Hellenic Plant Protection Journal

Volume 6, Issue 1, January 2013 ISSN 1791-3691 Hellenic Plant Protection Journal

A semiannual scientifi c publication of the BENAKIBEB PHYTOPATHOLOGICAL INSTITUTE The Hellenic Plant Protection Journal (ISSN 1791-3691) is the new scientifi c publication of the Benaki Phytopathological Institute (BPI) replacing the Annals of the Benaki Phyto- pathological Institute (ISSN 1790-1480) which had been published since 1935.

Starting from January 2008, the Benaki Phytopathological Institute is publishing the Hel- lenic Plant Protection Journal semiannually, in January and July each year, and accepts for publication any work related to plant protection in the Mediterranean region regardless of where it was conducted. All aspects of plant protection referring to plant pathogens, pests, weeds (identifi cation, biology, control), pesticides and relevant environmental issues are topics covered by the journal.

Articles in the form of either a complete research paper or a short communication (including new records) may be submitted. Instructions on how to prepare the manuscript are available in BPI’s website (www.bpi.gr). Manuscripts should be submitted in electron- ic form either by e-mail at [email protected] or by post on a disk addressed to the Edito- rial Board, Benaki Phytopathological Institute, 8 St. Delta Str., GR-145 61 Kifi ssia (Athens), Greece. Only original articles are considered and published after successful completion Hellenic Plant Protection Journal Protection Hellenic Plant of a review procedure by two competent referees.

EDITORIAL BOARD Editor: Dr F. Karamaouna (Pesticides Control & Phytopharmacy Department, BPI) Associate Editors: Dr A.N. Michaelakis (Entomology & Agric. Zoology Department, BPI) Dr K.M. Kasiotis (Pesticides Control & Phytopharmacy Department, BPI) Dr N.I. Skandalis (Phytopathology Department, BPI) M. Kitsiou (Library Department, BPI) Technical Editor and Secretary: Asteria Karadima (Information Technology Service, BPI)

For subscriptions, exchange agreements, back issues and other publications of the In- stitute contact the Library, Benaki Phytopathological Institute, 8 St. Delta Str., GR-145 61 Kifi ssia (Athens), Greece, e-mail: [email protected].

This Journal is indexed by: CAB Abstracts-Plant Protection Database, INIST (Institute for Scientifi c and Technical Information) and SCOPUS.

The olive tree of Plato in Athens is the emblem of the Benaki Phytopathological Institute

Hellenic Plant Protection Journal also available at www.bpi.gr

REVIEW ARTICLE

Eriophyoid mites (Acari: Eriophyoidea) in Greek orchards and grapevine: A review

E.V. Kapaxidi

Summary Eriophyoid mites (Acari: Prostigmata: Eriophyoidea), one of the most diverse group of mites, are plant feeder specialists, causing various symptoms on plants, and many of them are economically important pests on orchards and grapevines. They are commonly known as gall, rust, bud, and blister mites. Up to date approximately a hundred species of eriophyoid mites have been reported in Greece, thirty three of them, belonging to the families Eriophyidae, Diptilomiopidae and Phytoptidae, in agricultural orchards and vineyards. Information about their hosts, damage and natural enemies is pre- sented. Also, the subjects of monitoring and chemical control of eriophyoid mites are discussed.

Additional keywords: blister mites, bud mites, control, natural enemies, rust mites

Introduction one host genus, and 99% on one host family (Skoracka et al., 2010). Among phytophagous mites, the eriophyoid Symptoms of their feeding are varying mites (Acari: Prostigmata: Eriophyoidea) are from simple russeting to complex gall forma- the most diverse group and many of erio- tion and may appear on buds, shoots, stems, phyoid species are economically important twigs, fl owers and leaves of the plants. Gall pests (Van Leeuwen et al., 2010). Around formation occurs as a result of mite attack on 3,700 species are currently recognized (Am- individual plant cells; it is a localized growth rine et al., 2003) on angiosperms, coniferous reaction of the host plant to the attack. Com- plants and ferns throughout the world. They mon examples are leaf galls, bud galls, and are commonly known as gall, rust, bud, and erineum. In some plants, elongation of fl ower blister mites. stems and lateral branches is inhibited, caus- Members of the Eriophyoidea are soft ing the development of contorted foliage, bodied, wormlike, or spindle shaped, fl owers, and branches. One of the most con- unique among the mites because they have spicuous examples is witches’-broom, which only two pairs of legs and size so small that is a cluster of brush like growth of stunted they are almost invisible to the unaided eye. twigs or branches on trees. Some eriophy- Eriophyoids are one of the most specialized id species arrest shoot development, caus- groups of plant feeders. They are character- ing leaf sheaths to become enlarged, closely ized by the intimate relationships they have packed, and bunched at stem nodes. Others with their hosts and the restricted range cause the well-known “big bud”, which con- of plants upon which they can reproduce. sists of an aggregation of swollen, thickened Eighty per cent of eriophyoids have been scale leaves. Eriophyids also cause an array reported on only one host species, 95% on of nongall abnormalities, such as leaf fold- ing and twisting, blisters, and discoloration. Russeting and silvering or bronzing of leaves Laboratory of Acarology and Agricultural Zoology, De- are also induced by eriophyid feeding. As a partment of Entomology and Agricultural Zoology, 8 St. Delta str., GR-145 61 Kifi ssia (Athens), Greece result of infestation fl owers or young fruits e-mail: [email protected] maybe falling off (Keifer et al., 1982).

Eriophyoid mites (Acari: Eriophyoidea) Damage: The plum blister mite infests main- have been recognized as important pests ly almond and plum. On almond, it causes in agriculture and forestry all over the world permanent irregular galls of various sizes (Lindquist et al., 1996). A number of erio- around the buds and deforms the fruit. In- phyoid species are considered to be main fested trees fail to form fruit buds and lose pests on some crops, while others are vigor. On plum, the mites form small, irregu- known to be a quarantine threat for several lar, subsphaerical galls, 1.3-1.8 mm in diam- countries. Nevertheless, several eriophyoid eter surrounding the buds and also deform- species seldom attain high population lev- ing the fruit. The galls may appear singly els and thus their economic importance is a or clustered around the buds and become matter of discussion (Duso et al., 2010). woody. There are quite a few diffi culties evalu- On almond the damage appears to be ating eriophyoid population densities and progressive and irreversible resulting in related yield losses in most cases of erio- death of the tree in 3-6 years. Unlike almond, phyoid infestations. Their minute size and infested plum trees often recover from mite concealed way of life (several species live attack and do not show permanent injury and reproduce well hidden in buds or in in- (Keifer et al., 1982). duced plant structures, like galls, erinea and In the area of Magnesia (Central Greece) blisters) represent an obstacle for detailed on “Skopelos” plum tree the mite starts to studies aiming at determining their impact migrate from the galls to new buds in mid- on agricultural crops. The small size and the April and the migration phase lasts 50 days. behavior of eriophyoids are frequently im- Population builts up until December with plied in misdiagnoses with implications for successive generations, not damaging the yield losses (Duso et al., 2010). In contrast, production or the tree (Papanikolaou and their symptoms are sometimes spectacular Bakoyiannis, 1991). but not of economic impact. Knowledge of the economic impact of eriophyoids on crop Aculus fockeui (Nalepa and Trouessart) yields and threshold levels is a fundamental [Phyllocoptes fockeui Nalepa and Troues- requirement for the improvement of IPM. sart, Vasates fockeui (Nalepa and Troues- Up to date approximately 100 species of sart)] eriophyoid mites have been reported from Syn: Phyllocoptes cornutus Banks [Aculus cor- Greece (Malandraki, 2012), thirty three of nutus (Banks); Vasates cornutus (Banks)] them in agricultural orchards and grape- Phyllocoptes paracornutus Keifer vines. In Table 1, the name of the mite spe- Common name: plum rust mite cies and the host plant species as well as the Damage: This is a pest mainly of plums, corresponding references are summarised. peaches/nectarines and cherries in orchards Most of the papers are dealing with the tax- and nurseries. This mite produces asteroid onomic status, distribution records and con- chlorotic spots on leaves. When populations trol. A few studies deal with their biology are high the leaf is wavy or slightly twisted and control. about its longitudinal axis. Heavy infestations of A. fockeui may form rosette shoots and keep leaves from expanding to nor- Eriophyoid species in Greek orchards mal size. Deutogynes hibernate in niches or near the current season growth. They crawl Eriophyoids of stone fruits into bark crevices, especially around inju- ries, but are also behind potentially active Acalitus phloeocoptes (Nalepa) [Phy- buds, or under available loose bud scales. toptus phloeocoptes Nalepa, Eriophyes As the buds expand in spring the deutog- phloeocoptes (Nalepa)] ynes crawl to, and feed upon, emerging em- Common name: plum blister mite bryonic leaves and lay eggs. Trees are losing

© Benaki Phytopathological Institute Eriophyoids in Greek orchards and grapevine 3 , 2010; , 2010; et al. et , 1994; Malandraki,, 1994; 2012. , 1963; Hatzinikolis, 1967; Hatz- Hatzinikolis,, 1963; 1967; et al. et , 1963; Hatzinikolis, 1967; Hatzinik- Hatzinikolis,, 1963; 1967; et al. et ., 1994; Tzanakakis, 2003 Tzanakakis, ., 1994; et al. et et al et , 1994; Malandraki,, 1994; 2012. , 1994 et al. et et al. et , 1994; Malandraki,, 1994; 2012. , 1994; Malandraki,, 1994; 2012. , 1994 , 1994 et al. et et al. et et al. et al. et , 1994; Papaioannou-Souliotis, 1994; and Markoyiannaki, 2003; Tzanakakis, 2003; Malandraki, 2012. Papaioannou-Souliotis Papaioannou-Souliotis Hatzinikolis Papaioannou-Souliotis and Kolovos,1985; olis, 1969a; Hatzinikolis,olis, 1969a; Hatzinikolis, 1969b; Mourikis 1970b; and Vassilaina – Alexopoulou, 1975; Papaioannou-Souliotis Hatzinikolis, 1970c; Papaioannou-Souliotis Papaioannou-Souliotis 1970c; Hatzinikolis, Soueref and Komblas, 1961; Pelekassis, BouchelosSoueref 1962; and Komblas, 1961; inikolis, Hatzinikolis, 1969a; Hatzinikolis, 1969b; Hatzinikolis, 1969c; Hatzinikolis,1970d; 1970b; Hatzinikolis, MourikisHatzinikolis, and Emmanouel, Vassilaina – Alexopoulou, 1981; 1971; 1975; Hatzinikolis Hatzinikolis,1984; Hatzinikolis, and Kolovos,1985; 1986; Papaioannou-Souliotis 1989; al. et Kavadas, 1927; Koroveos, 1939; Pelekassis, Bouchelos Koroveos, 1962; 1939; Kavadas, 1927; Hatzinikolis, Hatzinikolis, 1969b; Hatzinikolis, Papanikolaou 1970a; 1970b; and Bakoyiannis, 1991; Papaioannou-Souliotis Papaioannou-Souliotis Malandraki, 2012. L. L. L. Hatzinikolis, Hatzinikolis, Hatzinikolis, 1969a; 1967; Hatzinikolis, 1969b; Koveos 1970b; L. Hatzinikolis, Hatzinikolis, 1968; Emmanouel, Hatzinikolis, 1969c; Hatzinikolis, 1981; 1970b; 1974; L. Kolovos,1985 and Hatzinikolis L. Ηatzinikolis, Papaioannou-Souliotis 1989; L. (L.) Osbeck L. Pelekassis, Hatzinikolis, Hatzinikolis, 1962; Hatzinikolis, 1969a; 1967; Hatzinikolis, 1969b; 1970b; L. Issakides, Hatzinikolis, Hatzinikolis, Hatzinikolis, 1936; 1969a; 1967; Hatzinikolis, 1969b; 1970b; (Mill.) D.A.Webb (Mill.) L. (L.) Burm, L. Hatzinikolis, Hatzinikolis, Papaioannou-Souliotis 1969b; 1970a; Olea europaea Olea Juglans regia Juglans Citrus limon Citrus sinensis Olea europaea Olea terebinthusPistacia Pistacia vera Olea europaea Olea Prunus domestica Prunus dulcis granatum Punica Juglans regia Juglans Ficus carica Olea europaea Olea (Nalepa) (Nalepa) (Hatzinikolis) (Nalepa) (Ewing) (Canestrini and and (Canestrini (Nalepa) Hatzinikolis (Nalepa) Zacher and Abou- (Cotte) List of known in Greek Eriophyoidea orchards and grapevine. Aculops benakii Aceria tristriatus Aceria Aceria sheldoni Aceria SpeciesEriophyidae phloecoptes Acalitus Hosts References Aceria olivi ( Awad) pistaciae Aceria Aceria cretica Aceria erineus Aceria cus Aceria fi granati Aceria Massalongo) Aceria oleaeAceria Table 1.

© Benaki Phytopathological Institute 4 Kapaxidi , et al. et , 1994; , 1994; , 1994; , 1994; et al. et , 1994; Malan-, 1994; et al. et et al. et ., 1963; Bouchelos., 1963; , 1994 et al et et al. et , 1994; Papaioannou-Souliotis and and Papaioannou-Souliotis 1994; , , 1994; Papaioannou-Souliotis and and Papaioannou-Souliotis 1994; , et al. et et al. et , 1994; Savopoulou-Soultani, 1994; and Koveos, 1993. Malandraki,, 1994; 2012. , 1994; Malandraki,, 1994; 2012. ., 2008 ., et al. et al. et et al. et et al et , 1994 , 1963; Hatzinikolis,, 1963; Hatzinikolis, 1969b; Hatzinikolis, 1970b; ., 1960; Pelekassis, 1962; Bouchelos Pelekassis,., 1960; 1962; et al. et et al. et et al et Kolovos,1985; Katsoyannos, 1992; Papaioannou-Souliotis Papaioannou-Souliotis 1992; Katsoyannos, Kolovos,1985; 1965; Hatzinikolis, 1967; Hatzinikolis, Hatzinikolis,1965; Hatzinikolis, 1969a; 1967; Hatzinikolis, 1969b; Mourikis 1970b; and Vassilaina-Alexopoulou, Katsoyannos, Papaioannou-Souliotis 1992; 1975; draki, 2012. Markoyiannaki, 2003; Anagnou-Veroniki Papaioannou-Souliotis 1970c; Koutroubas and Bakoyiannis, 1990 Bakoyiannis, and Koutroubas Savopoulou-Soultani Malandraki, and Koveos, 1993; 2012. Hatzinikolis, Hatzinikolis, Hatzinikolis, Papaioannou-Souliotis 1969b; 1970a; 1978; Papaioannou-Souliotis 1978; Hatzinikolis, Papaioannou-Souliotis 1978; Hatzinikolis, Keifer, 1959; Pelekassis, 1962; Hatzinikolis, 1967; Hatzinikolis, 1969a; Hatzinikolis, 1969b; Hatzi- 1969b; Hatzinikolis, 1969a; Hatzinikolis, 1967; Hatzinikolis, 1962; Pelekassis, 1959; Keifer, Mourikisnikolis, Papaioannou-Souliotis and 1970b; Vassilaina – Alexopoulou, 1975; Malandraki, 2012. Markoyiannaki, 2003; Tzanakakis, 2003; Malandraki, 2012. 2003; Tzanakakis, Markoyiannaki, 2003; Prunus Citrus deli- Borkh Borkh, Malus domesti- Malus L. Hatzinikolis, Hatzinikolis, 1969b; Papaioannou-Souliotis 1970c; L. L. Hatzinikolis, Papaioannou-Souliotis 1978; Mill. L. Hatzinikolis, Hatzinikolis, 1969b; Hatzinikolis, Emmanouel, 1969c; Hatzinikolis 1984; 1981; and L. Hatzinikolis Papaioannou-Souliotis and Kolovos,1985; (L.) Batsh, (L.) Osbeck L., Miller D.A. Webb Hatzinikolis, Hatzinikolis, Hatzinikolis, 1969a; 1967; 1969b L. Pelekassis Issakides, 1935; (L.) Burm, . avium

spp. Miller D.A. Webb Ten Borkh Olea europaea Olea Corylus avellana Corylus avellana L. Vitis vinifera Vitis Olea europaea Olea ca Malus domestica sylvestris Malus Malus domestica Pyrus communis Prunus persica dulcis Prunus Citrus sinensis Citrus Pyrus communis Prunus dulcis Citrus limon ciosa (Keifer) Keifer Keifer (Nalepa) (Nalepa) Pelekassis, Bouchelos 1962; (Keifer) (Nalepa) (Pagenstecher) Castanogli (Nalepa) (Nalepa and Ditrymacus athiasella Coptophylla lamimani Cecidophyopsis vermiformis (Nalepa) Colomerus vitis Aculus olearius Aculus schlechtentali Aculus Calepitrimerus baileyi Calepitrimerus vitis Aculus fockeui Aculus Trouessart) Epitrimerus pyri Eriophyes padi SpeciesAculops pelekassi Hosts References

© Benaki Phytopathological Institute Eriophyoids in Greek orchards and grapevine 5 , 1994; Papaioannou-Souliotis and and Papaioannou-Souliotis 1994; , et al. et , 1963; Hatzinikolis, Hatzinikolis,, 1963; 1967; 1969a; , 1994 , 1994; Malandraki,, 1994; 2012. , 1994; Malandraki,, 1994; 2012. , 1994; Malandraki,, 1994; 2012. et al. et et al. et et al. et et al. et et al. et , 1994; Malandraki,, 1994; 2012. et al. et , 1994;Malandraki, 2012. 1994;Malandraki, , et al. et Issakides, 1935; Pelekassis, 1962; Bouchelos Pelekassis,Issakides, 1962; 1935; Hatzinikolis, Hatzinikolis, Mourikis 1969b; 1970b; and Papaioan- Vassilaina – Alexopoulou, 1975; nou-Souliotis Papaioannou-Souliotis 1978; Hatzinikolis, Papaioannou-Souliotis 1970c; Hatzinikolis, Markoyiannaki, 2003. Papaioannou-Souliotis 1983; Hatzinikolis, Papaioannou-Souliotis Hatzinikolis Papaioannou-Souliotis and Kolovos,1985; Markoyiannaki, 2003. (L.) Citrus med- Pru- insititia L. L., Borkh L. Pelekassis, Hatzinikolis, Hatzinikolis, 1962; Hatzinikolis, 1969a; 1967; Hatzinikolis, 1969b; 1970b; L. L. L. Hatzinikolis, Hatzinikolis, 1969b; Hatzinikolis 1969c; and Kolovos,1985. Hatzinikolis, Hatzinikolis, 1969b; Hatzinikolis, 1969c; Papaioannou-Souliotis 1970d; and L. L. Hatzinikolis, Hatzinikolis, Hatzinikolis, 1967; 1969a; Hatzinikolis, 1969b; Emmanouel, 1969c; 1981; Kolovos,1985 and Hatzinikolis (L.) Batsh ssp. (L.) Obseck (L.) Burm, L. Hatzinikolis, Papaioannou-Souliotis 1982; L. Citrus limon Ficus carica Corylus avellana C.K.Schneid. ica Citrus sinensis Prunus domestica Prunus persica nus domestica europaea Olea europaea Olea Pyrus communis Malus domestica Olea europaea Olea europaea Olea Prunus domestica ) (Na- Keifer (Ash- Keifer (Natcheff Nalepa (Keifer) (Keifer) Zacher and and Zacher (Pagenstecher) Phyllocoptruta oleivora oleivora Phyllocoptruta mead) cifoliae fi Rhycaphytoptus Phytoptidae avellanae Phytoptus lepa) Diptilomiopidae gigantorhynchus Diptacus Oxycenus maxwelliOxycenus Shevtchenkella oleae Tegolophus hassani SpeciesEriophyes pyri Hosts References Oxycenus niloticus Abou-Awad abaenus Phyllocoptes

© Benaki Phytopathological Institute 6 Kapaxidi their vigor, sometimes they produce small- of apple worldwide. It causes patchy felt-like sized fruits that drop off (Keifer et al., 1982). malformation and a yellowing of hairs be- The plum rust mite is a frequent pest on low the leaves, the upper surface of foliage peaches in northern Greece and in some appearing speckly, dull and faded. In heavy cases develops high populations in summer infestations, it damages terminal growth; (July to August) mainly in upper young leaves the leaves curl lengthwise and become rusty (Savopoulou-Soultani and Koveos, 1993). brown, which gives the tree the appearance of being aff ected by drought. It also produc- Diptacus gigantorhynchus (Nalepa) [Phyl- es fruit russeting. The deutogynes fi nd rest- locoptes gigantorhynchus Nalepa, Ep- ing places under lateral buds not far below itrimerus gigantorhynchus (Nalepa), Rhyn- terminals, or in crevices on old wood. In the caphytoptus gigantorynchus (Nalepa), spring they move to opening buds, especial- Diptilomiopus gigantorhynchus (Nalepa)] ly during the bloom period (Jeppson et al., Syn: Diptacus prunorum (Keifer) [Diptilomio- 1975). pus prunorum Keifer] Common name: big-beaked plum mite Calepitrimerus baileyi Keifer Damage: Mites are vagrants on under leaf Syn: Calepitrimerus aphrastus (Keifer) [Phyllo- surface causing no apparent symptoms. coptes aphrastus Keifer] In some cases leaf discoloration or even Damage: This mite causes browning on the defoliation (Carmona, 1973; Bayan, 1988; underside of apple leaves. It is considered to Schliesske, 1992) may occur. Alford (2007) re- be of no importance. ported similar leaf symptoms to A. fockeui. It is considered of not economic importance. Diptacus gigantorynchus (Nalepa) [see stone fruits] Eriophyes padi (Nalepa) [Phytoptus padi Damage: It is considered to be of no impor- Nalepa] tance. Syn: Eriophyes eupadi (Newkirk) [Phytoptus eupadi Newkirk] Epitrimerus pyri (Nalepa) [Tegonotus pyri Common name: plum leaf gall mite Nalepa] Damage: It causes prominent, fi nger shaped, Syn: Epitrimerus pirifoliae Keifer red or dark red galls on the upper surface of Common name: pear rust mite plum foliage. The galls are often clustered Damage: This mite attacks both pear leaves closely together but cause little or no distor- and fruit in the spring. High infestations tion of leaves (Alford, 2007). It is considered cause severe browning of leaves and russet- of not economic importance. ing of fruit. Lower populations may injure only the calyx end of fruit. Phyllocoptes abaenus Keifer Clear-skinned fruit varieties show the Damage: It lives on undersides of plum most injury. In Greece the pear varieties leaves, including ornamentals and fre- “Kontoula” and “Krystalli” show great sus- quents basal hairs along midribs, causing ceptibility to the infestation causing reduc- not apparent symptoms. It is considered of tion of the product quality with economic not economic importance. impact (Papaioannou-Souliotis, 2001).

Eriophyoids of pome fruits Eriophyes pyri (Pagenstecher) [Phytoptus pyri Pagenstecher] Aculus schlechtendali (Nalepa) [Phyllo- Common name: pear leaf blister mite coptes schlechtendali Nalepa, Vasates Damage: It causes small galls, green at the schlechtendali (Nalepa)] beginning of the infestation, that gradual- Common name: apple rust mite ly turn to reddish and fi nally to dark brown. Damage: This species is a widespread pest At fi rst, the galls are along sides of the main

© Benaki Phytopathological Institute Eriophyoids in Greek orchards and grapevine 7 vein but as attack develops they cover most ophyll collapse, chlorosis, and leaf drop. It is of leaf surface. Badly infested leaves die and potentially capable of causing more dam- fall off . It also damages the fruitlets and fruit age to its host than citrus rust mite Phyllo- stalks, which may drop prematurely. coptruta oleivora (Jeppson et al., 1975). Aculops pelekassi was fi rst found in Eriophyoids of Citrus Greece in 1958 and since then its presence is frequent all over the country (Papaioannou- Aceria sheldoni (Ewing) [Eriophyes shel- Souliotis, 1985; Papaioannou-Souliotis et al., doni Ewing] 1994). It is active during mild winters and Common name: citrus bud mite can develop more than fi ve generations per Damage: The citrus bud mite feeds within year. In population outbreaks it can cause the buds causing variable symptoms such up to 60% loss of yield (Papaioannou-Souli- as distortion of shoot growth, excessive and otis, 1985). grotesque deformation of fruit, foliage, and blossoms, discoloration of fruit, and more Phyllocoptruta oleivora (Ashmead) commonly the production of numerous Common name: citrus rust mite buds. The last may develop abortive twigs in Damage: Its feeding destroys the epidermal tight clusters resembling “witches broom” cells of the rind, producing silvering or rus- and bunged terminal growth of distorted set eff ects. The ring of the aff ected fruit is stems and leaves. Most malformed fruits thicker than normal, and the fruit tends to drop prematurely. Mature lemon fruits show be smaller. Another result of the infestations blackened areas on the rind beneath the se- on lemons and grapefruit is a condition pals (buttons), where large colonies of mites known as “shark skin”, in which the outer are concealed. Deformed leaves and blos- layer of the skin can be peeled. Heavy popu- soms have various shapes; the leaf plates are lations of mites feeding on leaves and twigs constricted at their middle, curled, twisted, can also cause bronzing. divided and divergent at the tips; the blos- Greek citrus orchards are mainly infest- soms are stunted and abnormal. The symp- ed by A. pelekassi and A. sheldoni, which can toms of injury on oranges are similar to cause serious damage on fruit production those on lemons except fruit deformation is when outbreaks of their population occur not so grotesque. Aff ected oranges usually (Papaioannou-Souliotis, 1985, 1991, 1996; develop to maturity, but they are common- Papaioannou-Souliotis et al., 1992). P. oleivo- ly fl attened, resembling the shape of toma- ra only occur in limited part of orchards (Pa- toes; or they are skinfolds, seams and ridges, paioannou-Souliotis et al., 1994). or small apertures in the stylar end. Aceria sheldoni has been found in all Eriophyoids of Nut trees Greek citrus-growing regions, causing damage mainly in lemons, which can be signifi - Aceria erineus (Nalepa) [Phytoptus tristri- cant only during years with high population atus var. erineus Nalepa, Eriophyes tris- levels (Papaioannou-Souliotis, 1985; Papaio- triatus var. erineus (Nalepa), Eriophyes annou-Souliotis et al., 1999). erineus (Nalepa)] Common name: persian walnut erineum Aculops pelekassi (Keifer) [Aculus peleka- mite ssi Keifer, Vasates pelekassi (Keifer)] Damage: The infestation caused by this mite Common name: pink citrus rust mite is most noticeable as shiny convex swellings Damage: Pink rust mites not only cause rus- on the upper surface of the leaf blade and on seting of fruit and leaves, but also mild to the underside as patches of shallow, large, severe distortion of new growth, brown le- solitary concavities lined with felty, yellow- sions on lower surfaces and along midribs ish hairs, among which the mites are found. of immature leaves, and may produce mes- These patches have well defi ned edges and

© Benaki Phytopathological Institute 8 Kapaxidi lie to the side of the midrib between the lat- bud galls, known as big buds, consisting of eral veins; the erineum growths miss the an aggregation of swollen, thickened scale small secondary veins and appear as thick- leaves, often containing hundreds of mites. ened partitions. The erineum is particularly Their feeding activities suppress the devel- characteristic in that each structure is cov- oping young leaves or infl orescences closed ered with short, minute, unicellular hairs. Al- within the scales. Eventually the enlarged though erineum patches are fewer on the buds become dark and reddish brown as leaves, they are easily recognized because the immature. of their size and color. Aceria pistaciae (Nalepa) [Eriophyes pist- Aceria tristriatus (Nalepa) [Phytoptus tris- aciae Nalepa] triatus Nalepa, Eriophyes tristriatus (Nale- Common name: pistachio bud mite pa)] Damage: Lives on pistachio and turpentine Common name: persian walnut leaf gall/ trees causing fl ower stalk brooming and blister mite some leaf deformation on certain pistachio Damage: It infests leaves, preferably young species. The brooms are reddish and notice- and produces small, brown, hard pustules able. that are about 1¼ mm in diameter. The mites place these galls along midribs and Eriophyoids of Olive tree larger lateral veins, but in heavy infestations blisters occur elsewhere. Badly galled leaves Aceria cretica Hantzinikolis are twisted and misshapen (Castagnioli and Damage: The mite is found on the under leaf Oldfi eld, 1996). surfaces causing subcircular patches (Hatz- inikolis, 1989). It is a species that is reported Cecidophyopsis vermiformis (Nalepa) [Phy- only from Crete Island. toptus vermiformis Nalepa, Cecidophyes vermiformis (Nalepa), Eriophyes vermi- Aceria olea (Nalepa) [Eriophyes oleae Nale- formis (Nalepa)] pa, Phytoptus oleae (Nalepa)] Damage: It is found on common hazel tree Common name: olive bud mite usually in association with Phytoptus avella- Damage: This mite is a pest of all varieties of nae. It is considered of no economic impor- olive in the Mediterranean area and is espe- tance. cially injurious to young trees or the trees that have pollarded. It causes leaf and fruit defor- Coptophylla lamimani (Keifer) [Phyllocop- mation, and seriously reduces the amount tes lamimani Keifer] and quality of olives available for pickling. As Damage: It lives as leaf vagrant on under- the result of mite infestations and due to the side of hazel nut leaves causing no evident distraction of the normal silvery stellate hairs, symptoms. It is considered of no economic mature leaves may show subcircular, irregu- importance. lar greenish patches that turn brown as ne- crosis progresses. These patches may bulge Phytoptus avellanae Nalepa [Phytocop- out as small chlorotic areas above the gener- tella avellanae (Nalepa)] al leaf surface, giving the leaf an embossed Syn: Acarus pseudogalarum Vallot [Phytoptus appearance. In heavy infestations, the mites pseudogalarum (Vallot)] extend their feeding to leaf margins, which Phytoptus coryli Frauenfeld results in deformations. Damage on young Phytoptus coryligallorum Targioti-Tozzeti fruit fi rst appears as silvering, then browning [Eriophyes coryligallorum (Targioti-Tozzeti)] and ends in fruit deformation. Mites congre- Common name: fi lbert bud mite gate in large numbers at the stem end of the Damage: This species is considered as a mi- fruit, and fi nd shelter under sepal rudiments. nor pest of cultivated hazelnut. It produces Most damage to fruit is confi ned to the stem.

Fruits that are fully developed before the formation and discoloration. It is usually mites become abundant do not show much found on the upper surface of young leaves, damage. The species overwinters under the the fl owering buds and small fruits (Hatz- stellate hairs of the leaves and migrates ear- inikolis, 1982) and for a short period of time ly in spring in the fl owers where it stays until on fl owers (Castagnoli and Papaioannou- the fruit is formed. Souliotis, 1982) and older leaves (Castagno- In Greece, this mite appears very fre- li and Pegazzano, 1986). It usually coexists quently in high population densities main- with the other eriophyids and it is diffi cult to ly in regions with mild winters and humid estimate the damage caused by this single summers. In many cases it is found associ- species. Hatzinikolis (1982) reported defor- ated with A. benaki, D. athiasella, T. hassani mation of leaves and fl ower and young fruit (Hatzinikolis and Kolovos, 1985), and it is dropping due to the bud infestations. considered an occasionally serious pest. Ditrymacus athiasella attacks on the buds causing malformed leaves and infl o- Aceria olivi (Zaher and Abou-Awad) [Erio- rescences that fall off before full develop- phyes olivi Zaher and Abou-Awad] ment. On the leaves, mite attack is evident Damage: The mite forms characteristic from the appearance of yellow-white spots concave patches on the undersides of the on their upper surface which correspond leaves, and may cause malformation to the with swellings on the lower surface. Attacks succulent terminal leaves (Zaher and Abou- on the fl owers result in drying and fall of Awad, 1979). It is not considered of impor- fl owers together with the secondary axes of tance in Greece as its distribution is quite infl orescences. Infestation of the fruits takes limited (Hatzinikolis and Kolovos, 1985). place only during the fi rst stages of development, leading to premature drop of the Aculops benakii (Hatzinikolis) [Aculus fruits (Hantzinikolis, 1984). It has caused benakii Hatzinikolis] economic problems in Argolis and Arcadia Common name: olive yellow spot mite (Hatzinikolis, 1991) and reported to occur in Damage: It lives on the underside of olive great population densities causing econom- leaves under the stellate hairs. As a result ic damage in the olive oil producing areas of the stellate structures drop off , making yel- Peloponnese and central Greece. low leaf spots. In Greece it has been found mainly in Oxycenus maxwelli (Keifer) [Oxypleurites coastal areas, with mild winters and relative- maxwelli Keifer] ly cool and humid summers. It attacks leaf Common name: olive leaf and fl ower mite and fl ower buds, fl ower and young fruits. Damage: O. maxwelli feeds preferentially on It is of great economic importance in olive the upper surface of terminal leaves, but in growing locations in Western Greece, Crete high infestations it also feeds on the lower and Lesvos (Hatzinikolis and Kolovos, 1985). leaf surface, buds, new shoots, fl owers and stems (Jeppson et al., 1975). Heavy infesta- Aculus olearius Castagnoli tions may cause premature fl ower drop as Damage: It is found only in the infl orescenc- well as leaf spotted discoloration and dis- es from the emergence of the fl ower buds to tortion. High infestation of the mite on the setting of the fruit. It causes the brown- young leaves can cause silvering and distor- ing and withering of the fl ower and small tion, which reduces light absorption and de- fruits. It is not considered of importance in creases photosynthesis. Another problem Greece as its distribution is quite limited (Pa- attributed to infestations by O. maxwelli is paioannou-Souliotis et al., 1994). the reduction in internodal length, leading to the formation of overbudding (bunch- Ditrymacus athiasella Keifer top). In young plants, bud infestation can Damage: It produces some leaf pitting, de- lead to defi cient plant growth (Castagno-

© Benaki Phytopathological Institute 10 Kapaxidi li and Oldfi eld, 1996). Although O. maxwelli can be defoliation of branches or of whole is frequently present in Greek olive groves, trees. These mites make no galls (Keifer et Hatzinikolis and Kolovos (1985) reported al., 1982). that it was found in small populations and that is not a pest of economic importance Rhyncaphytoptus fi cifoliae Keifer for Greece. Common name: fi g leaf mite Damage: It lives as a vagrant among the un- Oxycenus niloticus Zaher and Abou-Awad der surface leaf hairs, causing no apparent Damage: The mite infests leaves preferring symptoms. the upper surface around mid-vein (Zaher and Abou-Awad, 1979). It forms characteris- Eriophyoids of pomegranate tic concave patches on the underside of leaf and may cause deformation to the succulent Aceria granati (Canestrini and Massalon- terminal leaves. Its distribution in Greece is go) [Phytoptus granati Canestrini and limited (Hatzinikolis and Kolovos, 1985). Massalongo, Eriophyes granati (Canestri- ni and Massalongo)] Shevtchenkella oleae (Natcheff ) [Tego- Common name: pomegranate leaf curl mite notus oleae Natcheff , Lovonotus oleae Damage: Pomegranate leaf curl mite occurs (Natcheff )] throughout Mediterranean region. The mite Damage: It attacks leaves, stems, buds and tightly rolls the leaves from the sides down infl orescences. It has been found in small onto the undersurface; these leaves maybe populations, and it is considered of no eco- so tightly rolled as to produce a nearly leaf- nomic importance in Greece. less appearance to the twig but the twigs continue to elongate, indicating the twig Tegolophus hassani (Keifer) [Tegonotus terminal is not damaged. hassani Keifer] Pomegranate culture has become pop- Common name: olive rust mite ular during the last decade in Greece. Aceria Damage: It lives on both surfaces of olive granati was reported to infest the orchards leaves and apparently causes russeting and of northern Greece (Drama) (Koveos et al., some form of leaf deformation or defolia- 2010), however its status as a pest is not yet tion. determined, as the extent of the infested or- It reaches high population levels in many chards and damages has not been studied. regions of the country where it is found in association with the other eriophyid species Eriophyoids of grapevine (Hatzinikolis and Kolovos, 1985) and may cause loss of production (Hatzinikolis, 1972). Calepitrimerus vitis (Nalepa) [Phytoptes vitis Nalepa, Epitrimerus vitis (Nalepa)] Eriophyids of fi g tree Common name: grapevine rust mite Damage: Heavy infestations of this species Aceria fi cus (Cotte) [Eriophyes fi cus Cotte] prevent vines from growing normally during Syn: Eriophyes fi ci Ewing the earlier parts of the season. Internodes Common name: fi g bud mite are shortened, foliage becomes bunched, Damage: This mite not only injures fi g buds, which interferes with proper pruning; grape but it also transmits fi g mosaic virus, a dis- production is reduced. Damage to grape ease that is present in Greece (Martelli et al., clusters occurs either because fl owers are 1993). Feeding by mites that carry no virus injured or because development is delayed. produces variable symptoms such as rus- The foliage has a browning and russeting as- seting or surface browning, bud blasting, pect. The leaves present malformation fol- impedance of new growth, bad distortion, lowed by a premature dropping. As a result leaf chlorosis, and in severe cases the result of the shortened internodes and the devel-

© Benaki Phytopathological Institute Eriophyoids in Greek orchards and grapevine 11 opment of additional shoots after the death Among the phytoseiid species that use of the main bud, the vine presents “witches mostly eriophyoid mites as a food source broom” appearance. are Iphiseius degenerans (Berlese), Euseius fi n l a n d i c u s (Oudemans), Euseius stipulatus Colomerus vitis (Pagenstecher) [Phytop- (Athias-Henriot), Kampimodromus aberrans tus vitis Pagenstecher, Eriophyes vitis (Pa- (Oudemans), Amblyseius andersoni (Chant), genstecher)] Typhlodromus (Typhlodromus) pyri Scheuten, Syn: Eriophyes vitis (Landois) [Phytoptus vitis Typhlodromus (Typhlodromus) exhilaratus Ra- Landois] gusa, Typhlodromus (Typhlodromus) athiasae Common name: grape bud mite or grape Porath and Swirski, Paraseiulus talbii (Athias- erineum mite Henriot) and species of the genus Neoseiu- Damage: Three forms of C. vitis have been lus (Sabelis, 1996; McMurtry and Croft, 1997; reported to cause diff erent types of inju- Kreiter and Tixier, 2010). Also, stigmaeid ry to grape vines. One form feeds on the mites, Zetzellia mali Ewing and Agistemus leaves and causes the appearance of patch- spp. are well-known predators of eriophyoid es of felty erineum on the lower surface, fol- mites (Abou-Awad et al., 1998; Childers et al., lowed by blister-like swellings on the upper 2001; Gerson et al., 2003; Duso et al., 2008). surface. The erineum patches are whitish at In Greece, many phytoseiid species fi rst, then yellow and fi nally reddish brown. are found in fruit orchards and vineyards. At times they are abundant in early spring Among the phytoseids recorded in stone in commercial vineyards or throughout the fruits, E. fi nlandicus, E. stipulatus, A. anderso- season on abandoned and backyard vines. ni and K. aberrans are the more frequent and Another form of C. vitis attacks grape buds, abundant. The stigmaeid predator Z. mali is causing deformation of the primordial bud also very frequent (Papaioannou-Souliotis clusters, distortion of the basal leaves, stunt- et al., 1994). Papanikolaou and Bakoyiannis ing of the main growing point, and often (1991) reported a hymenopteran larva (un- death of the overwintering buds. This form identifi ed species, probably belonging to does not produce erineum on the leaves. the family Eulophidae) associated with galls The third form produces leaf curl and abnor- of A. phloeocoptes, which showed very low mal plant hairs at the colonies sites. predation. Typhlodromus pyri, A. andersoni and E. fi n- landicus are frequent in apple orchards (Pa- Natural enemies paioannou-Souliotis et al., 1994; Markoyian- naki-Printziou et al., 2000; Papadoulis et al., Much of the ongoing research aiming at 2009) and may play a major role in keeping controlling eriophyoid mites in the last de- apple rust mite populations below econom- cade has been focused on biological control ic damage levels (Easterbrook 1996; Duso with the use or conservation of predatory and Pasini 2003; Fitzgerald et al., 2003). mites (van Leeuwen et al., 2010). Phytoseiid predatory species found in Predators of the eriophyoid mites in- citrus orchards in Greece include E. stipula- clude insects (Chalcidoidea, Thysanoptera) tus, Euseius scutalis (Athias-Henriot), Typhlo- and predaceous mites of Phytoseiidae, Stig- dromus (Anthoseius) athenas Swirski and Ra- maeidae and Anystidae (Jeppson et al., 1975; gusa, T. (T.) athiasae, P. talbii, A. andersoni and Sabelis, 1996). The importance of the preda- I. degenerans (Papadoulis et al., 2009). Euseius tory phytoseiid and stigmaeid mites for the stipulatus is the main phytoseiid predator control of eriophyoid mite populations has holding 80% of the phytoseiid population in been well documented by several authors citrus groves (Papaioannou-Souliotis, 1991). (Abou-Awad and El-Banhawy 1986; Ama- Generalist predators such as E. stipulatus can no and Chant 1986; Abou-Awad et al., 1998; control the phytophagous mite populations Abou-Awad et al., 2005). at low densities (McMurtry et al., 1992).

Ozman Sullivan (2006) evaluated the bi- this method, if many individuals are noticed, ology of the phytoseiid K. aberrans, a possi- more intensive sampling should be consid- ble predator of the big bud mite P. avellanae, ered, ideally with a dissecting microscope. which is a common pest in Greek hazelnut Hall et al. (2005, 2007) investigated the ef- orchards, and concluded that K. aberrans can fects of reducing the sample size on the ac- play an important role in IPM programmes curacy of estimation of citrus rust mite den- to control P. avellanae when it is released in sities in oranges and proposed a binomial early spring to boost the population before sampling based on the proportion of erio- P. avellanae migration. phyoid infested samples. In olive groves, predatory species of Phy- toseiidae comprise A. andersoni, T. (A.) athenas, Typhlodromus (Anthoseius) foenilis Chemical Control Oudemans, Typhlodromus (Typhlodromus) cotoneastri Wainstein and K. aberrans (Pa- In general, eriophyoid mites prove to be fair- paioannou-Souliotis et al., 1994; Papadoulis ly susceptible to the most commonly used et al., 2009). Euseius stipulatus, K. aberrans, E. acaricides, as was demonstrated by Childers fi n l a n d i c u sand Phytoseius plumifer (Canestri- et al. (1996) who made a thorough review of ni and Fanzago) are the most common spe- the chemical control of eriophyoids. Since cies found on fi g trees (Papaioannou-Souli- then there have been changes to registered otis et al., 1994). acaricides mostly in Europe, and most of the On pomegranate, the following phyto- substances tested are no longer in use. How- seiid species have been reported T. (A.) ath- ever, a rather limited amount of reports has enas, Typhlodromus (Anthoseius) psyllakisi investigated the suitability of modern crop Swirski and Ragusa, T. (T.) athiasae (Papadou- protection compounds for controlling rust, lis et al., 2009). Koveos et al. (2010) found an gall, blister and bud mites. Moreover, these unidentifi ed stigmaeid mite in association reports are mainly restricted to a number of with A. granati on pomegranate. major crops like citrus and apple orchards On grapevine, the most common and and major pests as P. oleivora and A. schlech- abundant species of Phytoseiidae are K. ab- tendali, respectively. The main reason for the errans, E. fi nlandicus, P. plumifer, T. (A.) athe- lack of information on the toxicity and other nas, T. (T.) exhilaratus and P. talbii, (Soulioti et aspects of new compounds can be probably al., 1998; Papadoulis et al., 2009). The stig- brought back to the lower economic impor- maeid mites Zetzellia graeciana Gonzalez tance of these mites, in comparison to oth- and Z. mali have also been reported (Papa- er mite pests such as the spider mites (Acari: ioannou-Souliotis et al., 1994). Tetranychidae). In Greece, there are no thresholds for the damage caused by eriophyoid mites. Monitoring The usual practice is acaricide or sulfur treatment when the infestation is evident to af- Monitoring eriophioid mites is a diffi cult task fect the trees’ vigor or yield. Registered ac- due to their minute size (average 100 μ) and aricides (active substances) for control of concealed way of life. The presence of erio- mites in orchards and grapevine are given phyoids is usually transpicuous when the in Table 2. symptoms become apparent. In the case of The usual practice for the management rust mites, monitoring involves collection of of A. phloeocoptes and A. fokeui in stone fruit leaves or fruits and counting the number of orchards is application of selective acari- mites. To assess populations, leaves should cides. For A. phloeocoptes application time is be examined with a hand lens with at least in early spring (March) at the opening of the 10x magnifi cation. Although it is impractical buds when the mites are migrating to new to obtain accurate population counts with buds while for A. fokeui it is in summer (Pa-

Table 2. Registered acaricides of tree orchards and grapevine in Greece (Authorized Plant Protection Products Data Base, Hellenic Ministry of Rural Development and Food, 2012) (http://wwww.minagric.gr/syspest/syspest_ENEMY_crops.aspx).

Crops Active substance of registered acaricides

Stone fruits Plum paraffi n oil, clofentezine fatty acid potassium salt, paraffi n oil, etoxazole and clofentezine Almond fatty acid potassium salt, paraffi n oil, acequinocil, clofentezine, etoxazole, hexythiazox, spirodiclofen and pyridaben Peach paraffi n oil

Cherry paraffi n oil, fatty acid potassium salt, clofentezine ,hexythiazox, tebufenpyrad, etoxazole, acequinocyl Citrus spp. paraffi n oil, fatty acid potassium salt, clofentezine, difl ubenzuron, etoxazole, fenpyroximate, tebufenpyrad, pyridaben, milbemectin, acequinocyl

Olive paraffi n oil

Nuts Walnut fatty acid potassium salt Pistachio none Hazelnut fatty acid potassium salt Fig tree none

Pomegranate none

Grapevine paraffi n oil, fatty acid potassium salt, sulphur, copper oxychloride, hexythiazox paioannou-Souliotis, 2001). pelekassi and A. sheldoni in citrus orchards, The recommended practice for infesta- selective acaricides should be applied tions of apple rust mite is pre-blossom treat- against A. pelekassi in summer (beginning of ment with paraffi n oil and/or summer spray- June) and autumn (mid-September to mid- ing with acaricides (Papaioanou-Soulioti, November) and against A. sheldoni in spring 2001). No threshold limit is established in and at the beginning of June (Papaioannou- Greece for A. schlechtendali. Ontario Minis- Souliotis, 1985). try of Agriculture, Food and Rural Aff airs re- In olive groves when outbreaks of erio- ports a threshold on apple rust mite pop- phyoids occur under favorable weather con- ulation, which is 200-500 mites per leaf ditions, two applications with sulfur or par- (Solymar and Walker, 2011). In lower popu- affi n oil are recommended, the fi rst early in lation, application must be avoided because spring before fl owering and the second 10- the apple rust mite provides valuable prey 15 days later (Broumas and Katsoyiannos, for predatory mites. 2009). In citrus groves in Greece, A. pelekas- In grapevine, it is well demonstrated si and A. sheldoni may develop high popu- that sulfur sprayings applied early in the lations when weather conditions are favor- spring can control mite populations e.g. able. In the case of high infestation of A. sulfur sprayings applied at the onset of the

© Benaki Phytopathological Institute 14 Kapaxidi wooly bud stage when mites become ac- important of future outbreaks of the erio- tive, followed by a second spraying approx- phyoid mite pests. imately 10 days later when late-develop- In general, eriophyoid mites are suscep- ing buds open. Papaioannou-Souliotis et al. tible to most commonly used acaricides, (1998) investigated the eff ect of some com- some insecticides and fungicides (especial- monly used fungicides and insecticides on ly sulphur). Τhe European Union review pro- phytoseiid populations in vineyards in four gramme of the existing active substances regions of Greece. under the Directive 91/414/EEC, resulted in There are no registered acaricides in the reduction of the available substances Greece for fi g and pomegranate cultivations. with acaricidal eff ect. The lack of registered The cultivation of fi g tree is traditional in acaricides for some cultivations such as southern parts of mainland Greece and the pomegranate in Greece, may cause a prob- Aegean islands, yet yield loss due eriophyoid lem in the future. infestation has been reported (Vachamid- The main problem with the control of is and Vemmos, 2010). Pomegranate culture eriophyoids is getting the compounds in has become popular during the last decade contact with the mites due to hidden life- in Greece. Aceria granati has been reported style of a number of important species. to infest cultivations in northern Greece re- Mites hiding in galls, blisters and buds are cently (Koveos et al., 2010) but the possible not easily accessible. In these cases, an ac- eff ect on yield is not yet determined. curate timing of the applications is crucial, in order to reach the life stages that (tempo- rarily) leave the hiding places, and can, only Discussion at those times, be reached with pesticides. That is why, in most cases, control is direct- The economic importance of eriophyoid ed against the adults which are searching mites has been estimated in some coun- for spots to induce their hiding places for tries but the variability of environmental the immature life stages (gall mites) or for conditions, cultural practices, cultivar fea- existing shelters (bud mites) and for a lim- tures and market standards make a gener- ited time, few days or weeks. Hence, control alisation based on these studies diffi cult. A is best succeeded with acaricides providing number of eriophyoid species emerged as long residual activity. On the other hand, economically important and their pest sta- rust mites have a more superfi cial lifestyle tus has been reconfi rmed recently, mainly in on the underside of leaves, leaving them ex- crops like citrus, apples, grapes, hazelnuts, posed throughout their life cycle and result- coconuts and tomatoes (Van Leeuwen et al., ing in easier control. In cropping systems 2010). In Greece, the economic importance where eriophyoid mites cause economic of eriophyoid mites as pests of orchards damage, such as apple and citrus orchards, and grapevine has not been much exploit- and Tetranychidae are also main pests, ap- ed. Most of them are considered occasion- plication timing and product choice should al pests whereas outbreaks often occur after refl ect concerns on the economic damage warm winters and springs with high rain- of both species. (Van Leeuwen et al., 2010). falls. The change in control strategies main- The conservation of indigenous natural ly towards the use of fungicides lacking ac- enemies for controlling eriophyoid mites is aricidal activity and of insecticides having a gaining more attention in the last decade detrimental eff ect on predatory mites might (Smith and Papacek, 1991). Morover, the cause outbreaks of rust mites and result in search for exotic natural enemies and re- the permanent pest status of the species lease remains an option, in cases that local (Easterbrook, 1996; Croft and Slone 1998). predators fail or are less successful in con- In addition, the climate change might be trolling these mite pests (Argov et al., 2002).

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ΑΡΘΡΟ ΑΝΑΣΚΟΠΗΣΗΣ

Ακάρεα της υπεροικογένειας Eriophyoidea σε δενδρώδεις καλλιέργειες και αμπέλι στην Ελλάδα

Ε.Β. Καπαξίδη

Περίληψη Τα ακάρεα της υπεροικογένειας Eriophyoidea απαντώνται σε όλες τις δενδρώδεις καλλι- έργειες και αμπελώνες της Ελλάδας. Είναι εξειδικευμένα παράσιτα φυτών και κάποια είδη μπορεί να προκαλέσουν ζημιές στην παραγωγή. Τα συμπτώματα που προκαλούν ποικίλουν από παραμορφώ- σεις φύλλων, βλαστών ή καρπών μέχρι και μεταχρωματισμούς. Μέχρι σήμερα τριάντα τρία είδη έχουν αναφερθεί στις δενδρώδεις καλλιέργειες και το αμπέλι στην Ελλάδα, τα οποία ανήκουν στις οικογένει- ες Eriophyidae, Diptilomiopidae και Phytoptidae. Στην παρούσα εργασία δίδονται στοιχεία για τους ξε- νιστές, την συμπτωματολογία, τους φυσικούς εχθρούς και την αντιμετώπισή τους ως εχθρούς των Ελ- ληνικών οπωρώνων και αμπέλου.

Hellenic Plant Protection Journal 6: 1-18, 2013

Ability of nitrogen containing salts to control the root-knot nematode (Meloidogyne javanica) on tomato

M.R. Karajeh1* and F.M. Al-Nasir2

Summary The infl uence of diff erent nitrogen containing salts and sodium chloride at gradual electrical conductivity levels (ECs 2, 4, 6 and 8 mS/ cm) on the root-knot nematode (Meloidogyne javanica) and their interaction with tomato was evaluated under growth chamber and greenhouse conditions.

Both ammonium chloride (NH4Cl) and ammonium sulfate ((NH4)2SO4) were more eff ective than ammonium nitrate (NH4NO3) which was more eff ective than potassium nitrate (KNO3) and sodium chloride (NaCl) in suppressing M. javanica by reducing root galling and nematode reproduction on tomato cv.

GS12. Under greenhouse conditions, the minimum signifi cant galling index values assessed for NH4Cl, (NH4)2SO4, NH4NO3 and KNO3 were 1.60, 2.04, 2.30 and 3.30, respectively whereas the maximum value (4.01) corresponded to NaCl and was not statistically diff erent from the control (4.92). A signifi cant increase in tomato growth and protein content for (NH4)2SO4 and NH4NO3 was observed. On the other hand, in NaCl treatment, there was a decrease in dry weights and protein content due to salinity compared with the control. The higher salt ECs did not aff ect the pH of the rhizospheric soil but slightly increased its measured EC and salinity. Hence, (NH4)2SO4 is a more suitable candidate than NH4Cl for the eff ective control of the root-knot nematode when irrigation water is a limiting factor with high salinity level similar to NaCl. Therefore, the use of ammonium containing salts especially (NH4)2SO4 and NH4Cl alone or in combination with other control measures may result in controlling M. javanica.

Additional keywords: fertilizers, management, Solanum lycopersicum, suppression

Introduction M. incognita have been demonstrated to shield tomato (Solanum lycopersicum Mill.) Root-knot nematodes (Meloidogyne Goldi roots from root knot nematode infection 1892 - RKN) are obligate parasites of high- in soil (Marks and Sayre, 1964; Edongali and er plants distributed worldwide and consid- Ferris, 1982; Ismail and Saxena, 1977; Castro + + - ered major nematode pests, causing great et al., 1991), furthermore, NH4 , K and NO3 crop losses annually (Sasser, 1987; Sasser have been recognized as benefi cial for plant and Freckman, 1987; Nickle, 1991) and regrowth (Castro et al., 1991). Root galling duction of product quality on almost every and M. incognita reproduction effi ciency in- plant species (Anastasiadis et al., 2011). creased in tomato plants exposed to ammo- Tenuta and Ferris (2004) reported that nia at 76μg/m3, while treatments with higher Meloidogyne javanica (Treub) Chitw. reared concentration (152μg/m3) caused nematode on solid medium and in hydroponic cul- suppression (Khan and Khan, 1995). Ad- ture, were slightly more sensitive to specifi c ditionally, urea and ammonium sulfate at ion and osmotic eff ects than nematodes of rates of more than 250mg N/kg soil resulted similar colonizer-persister groups obtained in suppression of M. incognita population on from soil. Also, gradients of salts of the spe- tomato plants (D’Addabbo et al., 1996). + + - - cifi c ion repellents (NH4 , K , Cl , and NO3 ) for Stimulation or depression eff ects of some salts on various plant physiologi- 1 Plant Protection and IPM Department, Faculty of Ag- cal functions are already known, especially riculture, when combined with other stressful agents 2 Plant Production Dept., Faculty of Agriculture, Mutah University, Karak P.O. Box 7, 61710 Jordan such as nematodes (Edongali and Ferris, * Corresponding author: muwaff [email protected] 1982).

The objectives of this study were to in- were surface-sterilized with 0.5% NaOCl. vestigate the eff ects of fi ve salts at four elec- All Petri dishes were kept at room tem- trical conductivity (EC) levels (2, 4, 6 and 8 perature for one hour before inoculating mS/ cm) on the control of the root nema- the tomato seedlings through pouring the tode M. javanica. The test salts comprised of solutions into the rhizospheric region of four nitrogen containing salts; ammonium each seedling one week after transplant- chloride (NH4Cl), ammonium nitrate (NH- ing. Each treatment was replicated fi ve

4NO3), potassium nitrate (KNO3) and ammo- times. The plants were regularly irrigated nium sulfate ((NH4)2SO4), and sodium chlo- with water. The treated and control plants ride (NaCl). The interaction of the eff ects were arranged according to a completely of the salts, the EC levels and the root-knot randomized design (CRD) and maintained nematode on the susceptibility and growth in a growth chamber at 25°C and 16/8 hour of tomato were also assessed under growth light/dark regime. chamber and greenhouse conditions. Six weeks after inoculation, the plants were up-rooted and the galling index evaluated according to the 0-5 scale: 0=no Materials and Methods galling, 1=1-2 galls, 2=3-10, 3=11-30, 4=31- 100 and 5=over 100 galls (Taylor and Sass- Analytical reagent grade of fi ve salts, er, 1978). Egg-masses were picked from the

NH4Cl, NH4NO3, KNO3, NaCl and (NH4)2SO4, roots, extracted with a 0.5% NaOCl solution was used. Electrical conductivity for each for 30 seconds (Hussey and Barker, 1973) salt solution used was 2 (EC2), 4 (EC4), 6 (EC6) and quantifi ed under a compound micro- and 8 (EC8) mS/ cm and was achieved by scope at 10X magnifi cation level. Nematode dissolving 1.07, 2.14, 3.21 and 4.28 g/l NH4Cl, reproduction factor (RF) was calculated as

1.60, 3.20, 4.80 and 6.39 g/l NH4NO3, 2.02, the number of eggs per plant (Pf) divided

4.04, 6.06 and 8.08 g/l KNO3, 1.17, 2.34, 3.50 by the initial J2 inoculum number (Pi). and 4.67 g/l NaCl or 2.63, 5.28, 7.92 and 10.55 g/l (NH4)2SO4, respectively, in water. Greenhouse experiment A fi eld population of M. javanica previ- To determine the eff ects and interactions of ously collected from a cucumber fi eld at M. javanica with variable levels of electrical Ein-Sarah region in Karak Province of Jordan conductivity of the fi ve salts on the growth and extracted in the laboratory was used for of tomato in greenhouse conditions, one- this study. The nematode population was month old seedlings (about 15cm tall) of to- morphologically identifi ed and molecular- mato cv. GS12 were tested. The seedlings ly characterized using the sequence charac- were planted in 5dm3 pots fi lled with 1.5 terized amplifi ed region-polymerase chain kg of a 1:2 mixture of water-washed sand reaction (SCAR-PCR) test (Karajeh, 2004). and a non-sodic, non-saline sandy loam soil (EC 1.3 mS/ cm, pH 7.1, 0.6% organic matter,

Infectivity test 1.1mg/g total nitrogen, and 43% CaCO3) that Two-week-old seedlings (ca. 5 cm tall) of M. had been previously sterilized at 85ºC for 5 javanica-susceptible tomato cv. GS12 were days. One week after transplanting, the de- transplanted into 100 ml plastic pots (one sired level of electrical conductivity (EC2, seedling/ pot), fi lled with a sterilized mixture EC4 and EC8) was achieved and maintained of 1:1:1 peat: sand: perlite. For each treat- by irrigating the soil with saline solutions ment, one thousand 2nd stage juveniles to fi eld capacity level for three consecutive (J2s) of M. javanica were picked and trans- weeks. For the control treatments, the same ferred into a small Petri dish containing 10 procedure was followed except that tap wa- ml of each solution at each EC or sterile tap ter replaced the salt solution. water (served as control). The juveniles were Each treatment was replicated six times two-days-old and hatched from eggs which (one plant per pot) and each seedling was

© Benaki Phytopathological Institute Control of Meloidogyne javanica with N-containing salts on tomato 21 inoculated with 3000 nematode eggs. In- icant reduction in nematode reproduction oculation was performed one day after salt expressed as lower RF values (Figure 1b). treatment by pouring the egg suspension Results from the greenhouse experi- of the nematode into three holes made in ment revealed that nitrogen containing the rhizospheric soil. Non-inoculated plants salts caused signifi cant reduction in toma- were used as controls. The plants were to root galling index, compared to the NaCl transferred into a greenhouse (25 ±5 oC air treatment and control, and this reduction temperature and 12/12 hour light/dark re- was clearer at higher EC levels (Table 1). The gime) and maintained without fertilization. minimum signifi cant galling index value

All treatments were arranged in a random- was observed for the NH4Cl treatment (1.60), ized complete block design (RCBD). regardless the EC level, followed by the

At the end of the experiment, sixty days (NH4)2SO4 (2.04), NH4NO3 (2.30), KNO3 (3.30), post-inoculation, plants were removed NaCl treatments (4.01) and the control (4.92) from the pots and the roots were carefully (Table 1). A similar pattern was observed in washed to remove soil particles. Fresh and the case of RF values since KNO3, NaCl and dry weights of plant shoots and roots were control caused profound nematode repro- recorded. The galling index and nematode duction, while the other salts showed a sig- reproduction factor were evaluated as pre- nifi cantly reduced reproduction (Table 1). viously described. After sieving and ground- There was a signifi cant increase in to- ing of 10g of the rhizospheric soil (oven mato plant and root dry weights and pro- dried) and dissolving it in distilled water, soil tein content in the treatments (NH4)2SO4 and pH, EC and salinity were measured using NH4NO3 over the control whereas the treat-

PCSTestr35 (Eutech Instruments, USA). Rep- ments NH4Cl and KNO3 were not signifi cant- resentative random samples of oven dried ly diff erent from the control. Nevertheless, plants were fi nely grounded and analyzed a decrease in dry weight and protein con- for protein, potassium and phosphorus content was observed in the NaCl treatment tent (Lowry et al., 1951; Meiwes et al., 1984). compared to the control (Table 1). In general, there was a signifi cant reduction in phos- Statistical analysis phorus plant content in the salt treatments Data were analyzed statistically using gener- over the control. The highest and most sig- al linear model (GLM) procedure (SPSS soft- nifi cant potassium content was observed for ware version 11.5; SPSS Inc., Chicago, USA). the KNO3 treatment (ca. 40g/kg) compared Signifi cance of main factors and interac- to the other salts and the control. There tions was tested at the 0.05 probability level. were no signifi cant pH diff erences among Least signifi cance diff erence (LSD) test was the treatments. As the EC level increased, used for mean separation at the 0.05 prob- there was a gradual increase of soil EC. The ability level. highest measured EC was recorded for the NaCl treatment (3.33 mS/ cm) at the highest EC (EC 8) and the lowest for the control Results (1.84mS/cm). Measured salinity was signifi -

cantly higher for NaCl and NH4Cl treatments Under controlled growth conditions, all ni- than for the other treatments. Potassium nitrogen containing salts were able to reduce trate did not cause a signifi cant increase in the extent of root galling over the control, the level of measured salinity over the con- with the exception of NaCl with EC levels at trol (Table 1).

2, 4 and 6 mS/ cm. Both NH4Cl and (NH4)2SO4 Root galling of tomato plants was aff ect- were relatively more eff ective in reducing ed mainly by the nematode, salt type and root galling index to less than 2 as com- the interaction between them and by their pared to KNO3 and NH4NO3 (Figure 1a) and interaction with EC (Table 2). The salt ef- this reduction was accompanied by a signif- fect was signifi cant on plant and root fresh

(a) Root galling index

(b) Nematode reproduction factor

Figure 1. Eff ect of fi ve Nitrogen containing salts at four levels of electrical conductivity (EC) on (a) root-galling (LSD0.05= 1.58 at P= 0.05) and (b) reproduction factor (LSD0.05= 2.41) of the root-knot nematode, Meloidogyne javanica, in tomato under growth incubator conditions. and dry weights and on the measured EC KNO3 and NaCl in suppressing M. javanica by (P≤0.05). The presence or absence of nem- reducing the rate of root galling and nema- atode was important for root dry weight. tode reproduction on tomato under labora- Electrical conductivity level, as a main fac- tory and greenhouse conditions. Akhtar and tor, had no signifi cance on the tested pa- Mahmood (1994) reported that the addition rameters (Table 2). of (NH4)2SO4 (110kg N/ha) reduced the total population of plant-parasitic nematodes as Discussion well as root-galling induction by M. incognita Tomato is a high fertilizer-input crop in on tomato, whereas it increased the number which the form of nitrogen is particular- of free-living nematodes. Other ammonia- ly important because it infl uences plant releasing compounds; NH4OH, (NH4)2HPO4 growth (Atherton et al., 1986) and plant re- and NH4HCO3, were also found eff ective sponse to a range of diseases (Hendrix and and showed the greatest nematicidal ac- Toussoun, 1964; Huber and Watson, 1974). tivity on M. javanica at concentrations of Ammonium chloride was previously report- 300mgN/kg soil. In a fi eld experiment, the ed to be more eff ective than KNO3 on to- nematicidal effi cacy of NH4OH on toma- mato (Karajeh and Al-Nasir, 2008) and this to plants at doses of 1000 and 2000kgN/ result was confi rmed in this study where ha was equivalent to those of metham so- another two ammonium-containing salts dium in combination with cadusafos (Oka

((NH4)2SO4 and NH4NO3) were additionally and Pivonia, 2002). Furthermore, the appli- tested. Ammonium sulfate was as eff ective cation of ammonium salts had a nematicidal as NH4Cl but NH4NO3 was less eff ective than eff ect against Pratylenchus penetrans (Cobb) both of these salts and more eff ective than Filipjev et Schuurmans Stekhoven (Walker,

© Benaki Phytopathological Institute Control of Meloidogyne javanica with N-containing salts on tomato 23 (ppt) produc- Salinity EC (mS/ cm) pH (0-14) phosphorus, K: potassium. potassium. K: phosphorus, (mg/g) Protein content K (g/kg ) Content P (g/kg) Content (g) RDW erent at 0.05 probability level using LSD. , in tomato pot plants, in tomato and soil and on plant properties. cantly diff cantly (g) PDW RF 2.21 d c 9.14 bc 2.19 d 1.56 34.31 c a 165.23 6.58 a d 2.11 c 1.04 Meloidogyne javanica 3 cd 2 GI (0-5) 1 482 d 1.68 4 d 1.60 8 2.89 cd d2 1.35 2.33 cd d4 1.31 2.04 2.31 d d 8 b 10.29 1.84 d 3.85 b2 8.29 cd 3.30 bc d4 1.67 b 11.40 bc 1.92 3.45 bc ab 12.61 8 8.40 b bc 1.90 3.44 b 4.35 c ab 2.66 12.59 ab d 1.52 2.30 3.60 cd cd 2.35 b4 ab 10.97 b 1.99 cd 2.70 1.86 bc8 bc 1.67 4.69 c 34.52 c c 9.74 3.58 cd d 1.41 c 9.18 b 37.50 a 1.50 d 31.00 4.53 a 3.90 c e 1.24 ab 12.81 d 56.10 ab 4.01 bc 1.73 a 34.44 13.01 c bc 1.74 c 91.33 c 1.75 bc 108.51 d 31.63 b 7.97 a 14.88 2.21 bc a 6.70 d 1.40 c 4.17 b 135.40 2.28 1.88 b bc 6.60 a b a 6.42 37.51 a 150.33 bc 1.88 bc 1.75 de b 2.92 7.95 40.65 a 6.51 a 40.50 a c 1.75 1.88 e 9.58 c c a 3.14 91.13 6.48 a d 30.10 1.88 bc ab 1.50 cd 1.51 55.64 d 2.20 d c 92.75 d 31.23 bc 6.55 a 0.94 1.74 c 2.63 bc b 134.50 d a 1.65 31.14 1.44 d 6.50 a 6.55 a c 82.34 cd 1.12 d 1.56 6.63 a 2.54 bc c 109.47 b 1.30 b 37.56 2.60 bc bc 2.70 6.58 a 6.55 a d 31.22 d 2.11 bc 1.22 bc 1.28 c 91.89 bc 1.20 2.20 d bc 2.71 d 60.13 c 1.08 6.64 a bc 1.23 b 1.42 6.53 a bc 2.75 3.33 a 1.54 ab a 1.77 EC (mS/ cm) ect of four nitrogen containing salts and NaCl at four levels of electrical conductivity (EC) on the root galling index and re and index galling root the on (EC) conductivity electrical of levels four at NaCl and salts containing nitrogen four of ect Eff 4 3 SO 2 3 ) Cl 2 2.31 NO 4 4 4 EC: electrical conductivity, GI: root galling index, RF= Reproduction factor, plant PDW: dry weight, RDW: root dry weight, P: Average of 6 replicates per each treatment. Means within columns followed by the same letters are not signifi Table 1. SaltType Root-Knot nematode properties Plant 1 2 3 properties Soil (NH KNO NH NaClControl 2 0 4.86 a a a 4.92 12.71 a 13.34 6.05 e 8.66 cd cd 1.58 d 1.45 1.54 cd b 34.33 c 2.17 d 31.24 c 78.10 106.25 bc 6.62 a 6.55 a 2.48 c 1.84 e b 1.25 c 0.91 NH tion factor of the root-knot nematode,

1971). A higher ammonium level in nutrient medium, in the presence or absence of excised roots, decreased the total number of

H, EC and and EC H, J2s that hatched from dispersed eggs and egg-masses (Sudirman and Webster, 1995). Increasing of ammonium levels reduced the percentage of J2s, which penetrated the roots over time as compared to the control (Sudirman, 1992). The mode of action of ammonium on the root-knot nematode can be explained by the assumption that higher concentrations of ammonium may have been suffi - cient to modify malate dehydrogenase activity (Viglierchio, 1979). This would have

, salt and electrical conductivity on root (EC) subsequently a) decreased the energy available for egg hatching and plant invasion processes and/or b) signifi cantly aff ected the electrical potential around the root tip area where J2s penetrated and thus infl u- enced nematode penetration of the roots through diminished attractiveness of the root tips (Scott and Martin, 1962) and/or c) Meloidogyne javanica signifi cantly inhibited giant cell formation salts at EC 2, 4 and 8 mS/cm.

4 and nematode development without aff ect- SO

2 ing root growth (Orion et al., 1980; Orion et ) 4 al., 1995). proteins, phosphorus and potassium and on measured of tomato p Increasing the salt EC level from EC2 up to EC8 resulted in decreasing the development of the root-knot nematode on tomato , NaCl, and (NH 3 and increasing plant growth. The higher salt EC did not aff ect the pH of the rhizospher- , KNO 3 ic soil but slightly increased its measured EC NO 4 and salinity. Hence, (NH4)2SO4 is a more suitable candidate for the control of the nema- Cl, NH 4 tode than NH4Cl, which showed similar sa- PFW RFW PDW RDW Protein P K pH EC Salinity 0.002 0.031 0.003 0.032 0.320 0.123linity 0.799level to 0.115 NaCl. 0.001 0.629 In a previous report where the eff ect of ects of the (probability nematode values)

2 concentration gradient of KNO3 on horizon- 1 cant. tal migration of M. javanica J2s was studied, the juveniles moved preferentially toward the lower mineral salt concentration region (Prot, 1979). However, in our experiments,

high concentrations of nitrate as KNO3 did not considerably aff ect nematode infection or reproduction on the host. This is in Main and interaction eff an agreement with the results of other studies (Marks and Sayre, 1964; Ismail and Saxe- na, 1977). GI: root galling index, plant PDW: dry weight, RDW: root dry weight, P: phosphorus, K: potassium. Probability values ≤ 0.05 are signifi Nematode 0.002ECSalt x Nematode 0.353Salt x ECEC x Nematode 0.718Salt x Nematode x EC 0.030 0.726 0.039 0.284 0.011 0.245 0.171 0.111 0.317 0.084 0.803 0.110 0.320 0.310 0.612 0.609 0.415 0.967 0.320 0.722 0.478 0.081 0.310 0.706 0.295 0.797 0.101 0.224 0.062 0.583 0.715 0.894 0.157 0.659 0.124 0.145 0.210 0.198 0.400 0.577 0.104 0.141 0.251 0.078 0.147 0.048 0.257 0.766 0.233 0.806 0.046 0.764 0.061 0.592 0.097 0.892 0.057 0.276 0.158 0.288 0.540 0.322 0.530 galling, plant and root fresh and dry of weights, plant contents Table 2.:Table Source GI Experimental analysis based on 6 replicates for NH 1 2 Salt 0.028 salinity of rhizospheric soil at a pot experiment. Generally, ammonium was more effi -

© Benaki Phytopathological Institute Control of Meloidogyne javanica with N-containing salts on tomato 25 cient than nitrate. Meloidogyne incogni- This work is part of a research project fi nancial- ta resistant tomato cultivar ‘VFN-8’ and the ly supported by the Scientifi c Research Support moderately susceptible one ‘Rutgers’ grew Fund of Jordan and coordinated by the Scien- better when ammonium nitrate was com- tifi c Research Deanship of Mutah University, pared to the control. Ammonium could re- Karak, Jordan. duce nematode numbers less than nitrate in the resistant cultivar (Melakeberhan, 1998). The orientation of juveniles of M. incognita Literature Cited was induced by the constitutive salt cation e.g. calcium salts had no eff ect while other Akhtar, M. and Mahmood, I. 1994. Nematode pop- salts, especially those with ammonium were ulations and short-term tomato growth in response to neem-based products and other soil strongly nematode repellent (Le Saux and amendments. Nematropica, 24: 169-173. Queneherve, 2002). Anastasiadis, I., Kimbaris, C., Kormpi M., Polissiou, Compared with the nitrogen containing M.G. and Karanastasi, E. 2011. The eff ect of a salts, NaCl aff ected tomato growth due its garlic essential oil component and entomo- salinity eff ect, therefore it cannot be used pathogenic nematodes on the suppression of Meloidogyne javanica on tomato. Hellenic Plant for controlling the disease when irrigation Protection Journal, 4: 21-24. water is a limiting factor. Atherton, J.G. and Rudich, J. 1986. The Tomato Crop: No phytotoxicity was observed when ni- Scientifi c Basis for Improvement. London, UK, trogen containing salts were applied at all Chapman and Hall, 661 p. EC levels which complies with previous re- Castro, C.E., McKinney, H.E. and Lux, S. 1991. Plant ports that indicate induced phytotoxicity by protection with inorganic ions. Journal of Nem- atology, 23: 409-413. some nitrogen containing salts (Rodríguez- D’Addabbo, T., Filotico, A. and Sasanelli, N. 1996. Ef- Kabana, 1986), although this was considered fect of calcium cyanide and other ammonia fer- a dose-dependent issue. tilizers on Meloidogyne incognita. Nematologia The combination of nitrogen contain- Mediterranea, 24: 209-214. ing salts with other control measures e.g. Edongali, E.A. and Ferris, H. 1982. Varietal response soil-solarization may increase their effi cacy of tomato to the interaction of salinity and Mel- oidogyne incognita infection. Journal of Nema- on the control of root-knot nematode (Mc- tology, 14: 57-62. Sorley and McGovern, 2000). The manage- Gamliel, A. and Stapleton, J.J. 1993. Eff ect of chick- ment of M. incognita was improved when en compost or ammonium phosphate and so- soil-solarization was combined with ammo- larization on pathogen control, rhizosphere nium phosphate or composted chicken litter microorganisms, and lettuce growth. Plant Dis- ease, 77: 886-891. (Gamliel and Stapleton, 1993) while the ef- Hendrix, F.F.Jr. and Toussoun, T.A. 1964. Infl uence of fect of solarization was not enhanced by the nutrition on sporulation of the banana wilt and combination with ammonium amendments, bean root rot Fusaria on agar media. Phytopa- except for one instance where application of thology, 54: 389-392. Huber, D.M. and Watson, R.D. 1974. Nitrogen form ammonium bicarbonate or (NH4)2SO4 resulted in lower numbers of Belonolaimus longi- and plant disease. Annual Review Phytopatholo- caudatus than in the unamended control gy, 12: 139-165. (McSorley and McGovern, 2000). Moreover, Ismail, W. and Saxena, K. 1977. Eff ect of diff erent levels of potassium on the growth of root-knot Oka et al., (2007) reported that soil applica- nematode, Meloidogyne incognita, on tomato. tion of ammonium sulfate in combination Nematologica, 23: 263-264. with Neem extract signifi cantly reduced root Karajeh, M.R. 2004. Identifi cation, Distribution, and galling caused by M. javanica. Therefore, the Genetic Variability of the Root-Knot Nematodes use of (NH ) SO and NH Cl alone or in com- (Meloidogyne spp.) in Jordan. Ph.D. Thesis, Uni- 4 2 4 4 versity of Jordan, Amman, Jordan, 152 p. bination with other control measures e.g. or- Karajeh, M.R. and Al-Nasir, F.M. 2008. Salt suppres- ganic amendments and/or soil solarization sion of root-knot nematode (Meloidogyne ja- could improve the management of M. javan- vanica) in tomato. Nematologia Mediterranea, ica. 36: 185-190.

Khan, M.R. and Khan, M.W. 1995. Eff ects of ammo- Prot, J.C. 1979. Horizontal migrations of second- nia and root-knot nematode on tomato. Agricul- stage juveniles of Meloidogyne javanica in sand ture, Ecosystems and Environment, 53: 71-81. in concentration gradients of salts and in a mois- Hussey, R.S. and Barker, K.R. 1973. A comparison of ture gradient. Revue Nematologie 2:17-21. methods of collecting inocula of Meloidogyne Rodríguez-Kabana, R. 1986. Organic and inorganic spp. including a new technique. Plant Disease nitrogen amendments to soil as nematode sup- Reporter, 57: 1025-1028. pressants. Journal of Nematology 18: 129–135. Le Saux, R. and Queneherve, P. 2002. Diff erential Sasser, J. 1987. A Perspective on Nematode Problems chemotactic responses of two plant-parasitic Worldwide. Workshop on Plant-Parasitic Nema- nematodes, Meloidogyne incognita and Rotylen- todes in Cereal and Legume Crops in Temperate chulus reniformis, to some inorganic ions. Nema- Semiarid Regions, Larnaka, Cyprus, 1-5 March. tology, 4: 99-105 (abstract). Sasser, J. and Freckman, D. 1987. A World Perspec- Lowry, O.H., Rosebrough, N.J., Farr, A.L. and Randall, tive on Nematology: The Role of the Society. Pp. R.J. 1951. Protein measurement with the Folin- 7-14 In: Veech, J. and Dickson, D. (eds). Vistas on Phenol reagents. Journal of Biological Chemistry, Nematology. Society of Nematologists, Hyatts- 193: 265-275. ville, Maryland. 509 p. Marks, C.F. and Sayre, R.M. 1964. The eff ect of po- Scott, B.I. and Martin, D.W. 1962. Bioelectric fi elds of tassium on the rate of development of the root- bean roots and their relation to salt accumula- knot nematodes Meloidogyne incognita, M. ja- tion. Australian Journal of Biological Sciences, 15: vanica and M. hapla. Nematologica, 10: 323-327. 83-100. McSorley, R. and McGovern, R.J. 2000. Eff ects of Siddiqui, I.A. and Shaukat, S.S., Khan, G.H. and Ali, solarization and ammonium amendments on N.I. 2003. Suppression of Meloidogyne javanica plant-parasitic nematodes. Journal of Nematol- by Pseudomonas aeruginosa IE-6S+ in tomato: ogy, 32: 537-541. the infl uence of NaCl, oxygen supply and iron. Meiwes, K.J., König, N., Khanna, P.K., Prenze, J. and Soil Biology and Biochemistry, 35: 1625-1635. Ulrich, B. 1984. Chemische Untersuchungsver- Sudirman, I. 1992. Eff ect of Ammonium on Root-Knot fahren für Mineralböden, Aufl agehumus und Nematode, Meloidogyne incognita, in Excised To- Wurzeln zur Charakterisierung und Bewertung mato Roots. M.Sc. Thesis. Simon Fraser Universi- der Versauerung von Waldböden. Rep. Forst ty, Canada, 124 p. Ecosystem Research Center at the Göttingen Sudirman, I. and Webster, J.M. 1995. Eff ect of ammo- University (Göttingen, Germany) 7, 1-67. nium ions on egg hatching and second-stage Melakeberhan, H. 1998. Eff ects of temperature and juveniles of Meloidogyne incognita in axenic to- nitrogen source on tomato genotypes response mato root culture. Journal of Nematology, 27: to Meloidogyne incognita infection. Fundamen- 346-352. tal applied Nematology, 21: 25-32. Taylor, A.L. and Sasser, J.N. 1978. Biology, Identifi ca- Nickle, W.R. 1991. Manual of Agricultural Nematology. tion and Control of Root-Knot Nematodes (Melo- New York, NY: Marcel Dekker. 1035 p. idogyne spp.). North Carolina State University Oka, Y. and Pivonia, S. 2002. Use of ammonia-re- Graphic, Raleigh, NC, USA, 111 p. leasing compounds for control of the root-knot Tenuta, M. and Ferris, H. 2004. Sensitivity of nem- nematode Meloidogyne javanica. Nematology, 4: atode life-history groups to ions and osmot- 65-71. ic tensions of nitrogenous solutions. Journal of Oka, Y., Tkachi, N., Shuker, S. and Yerumiyahu, U. Nematology, 36: 85-94. 2007. Enhanced nematicidal activity of organic Viglierchio, D.R. 1979. Selected aspects of root-knot and inorganic ammonia-releasing amendments nematode physiology. Pp. 114-154. In: Root- by Azadirachta indica extracts. Journal of Nema- Knot Nematodes (Meloidogyne species) (Lam- tology, 39: 9–16. berti L. and Taylor C.E., eds). Academic Press, Orion, D., Wergin, W.P. and Endo, B.Y. 1980. Inhibi- New York, USA. tion of syncytia formation and root-knot nema- Walker, J.T. 1971. Populations of Pratylenchus pene- tode development on cultures of excised toma- trans relative to decomposing nitrogenous soil to roots. Journal of Nematology, 12: 196-203. amendments. Journal of Nematology, 3: 43-49. Orion, D., Wergin, W.P. and Chitwood, D.J. 1995. Root cortical cell spherical bodies associated with an induced resistance reaction in monoxenic cultures of Meloidogyne incognita. Journal of Nema- tology, 27: 320-327. Received: 15 May 2012; Accepted: 19 October 2012

© Benaki Phytopathological Institute Control of Meloidogyne javanica with N-containing salts on tomato 27 Αποτελεσματικότητα των ανόργανων αλάτων αζώτου στην αντιμετώπιση του νηματώδη Meloidogyne javanica στην τομάτα

M.R. Karajeh και F.M. Al-Nasir

Περίληψη Στην παρούσα εργασία μελετήθηκε η επίδραση διαφόρων ανόργανων αλάτων αζώτου και του χλωριούχου νατρίου σε συνδυασμό με αυξανόμενα επίπεδα ηλεκτρικής αγωγιμότητας (ECs 2, 4, 6 and 8 mmhos/cm) στον νηματώδη Meloidogyne javanica και η αλληλεπίδραση αυτών των παρα- γόντων σε φυτά τομάτας cv. GS12, σε συνθήκες εργαστηρίου και στο θερμοκήπιο. Το χλωριούχο αμ-

μώνιο (NH4Cl) και το θειικό αμμώνιο [(NH4)2SO4] ήταν περισσότερο αποτελεσματικά από το νιτρικό αμ- μώνιο (NH4NO3), το οποίο ήταν πιο δραστικό από το νιτρικό κάλιο (NH4NO3) και το χλωριούχο νάτριο (NaCl) στην καταστολή του M. javanica προκαλώντας μείωση των όγκων στις ρίζες και στην αναπαρα- γωγή των νηματωδών στα φυτά της τομάτας. Σε συνθήκες θερμοκηπίου, οι ελάχιστες σημαντικές τι-

μές του δείκτη παρουσίας όγκων στις ρίζες ήταν 1,60, 2,04, 2,30 και 3,30, στις επεμβάσεις με NH4Cl, (NH4)2SO4, NH4NO3 και KNO3 αντίστοιχα, ενώ η μέγιστη τιμή (4,01) παρατηρήθηκε στο NaCl και δεν διέ- φερε στατιστικά σημαντικά από το μάρτυρα (4,92). Επιπλέον, παρατηρήθηκε σημαντική αύξηση στην

ανάπτυξη των φυτών τομάτας και στην περιεκτικότητα τους σε πρωτεϊνη στις επεμβάσεις με (NH4)2SO4 και NH4NO3. Αντίθετα, στην επέμβαση με NaCl, το ξηρό βάρος των φυτών και η περιεκτικότητα σε πρω- τεϊνη ήταν μειωμένη λόγω της αλατότητας σε σχέση με τον μάρτυρα. Οι υψηλότερες τιμές ηλεκτρικής αγωγιμότητας στα διαλύματα των αλάτων αζώτου δεν επηρέασαν το pH του εδάφους της ριζόσφαιρας

αλλά αύξησαν ελαφρώς την ηλεκτρική αγωγιμότητα και την αλατότητά του. Συνεπώς, το (NH4)2SO4 εί- ναι καταλληλότερο άλας ανόργανου αζώτου από το NH4Cl για την αποτελεσματική αντιμετώπιση του νηματώδη M. javanica όταν το νερό άρδευσης είναι περιοριστικός παράγοντας με επίπεδα αλατότητας

ανάλογα με αυτά του NaCl. Η χρήση αμμωνιακών αλάτων, ειδικά (NH4)2SO4 και NH4Cl, από μόνη της ή σε συνδυασμό με άλλα μέτρα αντιμετώπισης μπορεί να είναι αποτελεσματική στην αντιμετώπιση του νηματώδη M. javanica.

Hellenic Plant Protection Journal 6: 19-27, 2013

Hellenic Plant Protection Journal 6: 29-39, 2013

Fumigant toxicity of six essential oils to the immature stages and adults of Tribolium confusum

G. Theou1, D.P. Papachristos2* and D.C. Stamopoulos3

Summary Six essential oils derived from Lavandula hybrida, Laurus nobilis, Thuja orientalis, Citrus sinensis, Citrus limon, and Origanum vulgare were evaluated in a preliminary fumigation screening test on 10-, 25- and 31-days-old larvae, 2-days-old pupae and 10- and 60-days-old adults of Tribolium confusum. Beetles were exposed to essential oils’ vapors at a series of concentrations ranging from 0.27 to 165 μl/l of air depending on the essential oil, insect developmental stage, age and sex. All but O. vulgare essential oils exhibited strong fumigant toxicity to all developmental stages of T. confusum. In general, 10 day-old larvae were the most susceptible and the 25 and 31 day-old larvae were the most tolerant. LC50 values ranging between 1.8 and 109 μl/l air depending on the essential oil and insect developmental stage, age and sex. Furthermore, pupae exposed to these essential oil vapours showed various degrees of inhibition of morphogenesis.

Additional keywords: Adultoids, developmental stage, inhibition of morphogenesis, mortality, larvae, pupae

Introduction mammalian toxicity (Hall and Oser, 1965; Is- man, 2000) and degrade rapidly in the envi- The measures used worldwide to con- ronment (Rebenhorst, 1996; Misra and Pav- trol stored product insect infestations rely lostathis, 1997). mainly on the use of fumigants such as me- Apart from their fumigant and acute tox- thyl bromide and phosphine. However, their icity against a wide spectrum of insect pests usefulness is severely limited by their ad- (Huang et al., 1997; Shaaya et al., 1997; Pa- verse eff ects on the environment and non- pachristos et al., 2004; Rajendran and Sriran- target organisms (Dansi et al., 1984; Fields jini, 2008; Michaelakis et al. 2009; Wang et and White, 2002) and by the development of al., 2009; Michaelakis et al., 2011), they can resistance (Boyer et al., 2012). This situation also act as repellents (Jilani et al., 1988; Pa- led researchers to develop safe, low-cost al- pachristos and Stamopoulos, 2002; Kumar et ternatives that are convenient to use and al., 2011; Giatropoulos et al., 2012), antifeed- environmentally friendly. Among the most ants or they can adversely aff ect the growth promising of these agents are essential oils rate, reproduction and behaviour of insect directly toxic to bacteria, fungi and insects pests (Stamopoulos, 1991; Liu and Ho, 1999; (Isman, 2000; Isman and Machial, 2006). Papachristos and Stamopoulos, 2002; Sta- Equally important, essential oils have low mopoulos et al., 2007; Papachristos and Sta- mopoulos, 2009; Ebadollahi, 2011). Insects belonging to the family Tenebri- 1 Laboratory of Applied Zoology and Parasitology, Ari- stotle University of Thessaloniki, GR-540 06 Thessalo- onidae and especially to the genus Tribolium niki, Greece are considered major pests of stored prod- 2 Laboratory of Agricultural Entomology, Department of Entomology and Agricultural Zoology, Benaki Phy- ucts. Both Tribolium confusum Jacquelin du topathological Institute, 8 St. Delta Str., GR-145 61 Ki- Val and Tribolium castaneum (Herbst) at- fi ssia (Athens), Greece tack a wide range of starchy materials such 3 Laboratory of Zoology and Aquatic Entomology, De- partment of Agriculture, Ichthyology and Aquatic En- as fl our, bran or cracked grain kernels, and vironment, School of Agriculture, University of Thes- can occasionally be found in dried fruits, saly, GR-382 21 Volos, Greece * Corresponding author: [email protected] spices and chocolate (Aitken, 1975; Mills and [email protected] Pedersen, 1990). Moreover, species belong-

© Benaki Phytopathological Institute 30 Theou et al. ing to genus Tribolium are known to secrete a Clevenger apparatus (Winzer®), from the carcinogenic chemicals known as quinones following plant parts: L. hybrida (whole fl ow- when they occur in large numbers (Hodges ering plants), L. nobilis (fruits and leaves), T. et al., 1996). orientalis (fruits), C. sinensis (peels from ma- Although the fumigant action of many ture fruits), C. limon (peels from mature essential oil vapours against T. castaneum fruits), O. vulgare (whole fl owering plants). has been studied thoroughly (Kim et al., The plants were collected in mid July from 2010; Liu and Ho, 1999; Mediouni et al., 2012; the region of Thessaloniki (Northern Greece) Mohamed and Abdelgaleil, 2008; Mondal except for the fruits of C. sinensis and C. and Khalequzzaman, 2010; Rice and Coats, limon, which were collected in December 1994; Safavi and Mobki, 2012), very little from the area of Arta (Western Greece). The relevant information is available on T. con- distilled essential oils were dried over anhy- fusum (Haouas, 2012; Işikber et al., 2006; drous sodium sulphate and stored in a freez- Işikber et al., 2009), a very common spe- er at -10ºC until use. cies in Northern Greece and well adapted at the cold-dry environments of most store- Bioassays houses (Stamopoulos et al., 2007). The two In order to test the toxicity of essential oil aforementioned species are known to diff er vapours to the immature stages and adults in many aspects of their response and sus- of T. confusum, gastight glass jars of 370 ml ceptibility to xenobiotic compounds (Amos volume with metal screw-caps were used as et al., 1974; Arthur, 2003). Moreover, essen- exposure chambers. A small piece (3 x 3 cm) tial oils while are generally active against a of Whatman No 1 fi lter paper was attached broad spectrum of stored product pests, in- to the undersurface of the cap to serve as an terspecifi c toxicity of individual oils is highly oil diff user after the appropriate amount of idiosyncratic (Isman, 2000). pure essential oil had been applied. Doses The present study was undertaken to in- were calculated based on nominal concen- vestigate the toxicity of Lavandula hybrida trations and assumed 100% volatilisation of Rev. (Lamiaceae), Laurus nobilis L. (Lauraceae), the oils in the exposure vessels. Thuja orientalis L. (Cypressaceae), Citrus sinen- In each jar, 20 insects were placed at the sis Osbeck. (Rutaceae), Citrus limon Osbeck. appropriate stage of development i.e. 10-, (Rutaceae) and Origanum vulgare L. (Lamiace- 25- and 31-days-old larvae, 2-days-old pupae ae) essential oil vapours on T. confusum larvae, (males and females were exposed separate- pupae and adults. The relation between the ly) and 10- and 60-days-old adults (males and age, stage and sex of the insect and its vulner- females were exposed separately) were used. ability to these vapours were also studied. Males and females were separated as pupae based on morphological characteristics of genital papillae and kept separately until Materials and methods their use. In females, the genital papillae are pointy, with 2 darker dots on the tip of each, Biological material and roughly half the size of the urogomphi Tribolium confusum larvae, pupae and whereas those of males are stubby, conjoined adults were obtained from laboratory cul- and barely noticeable (Park, 1934). tures maintained in large glass jars (30 cm After 48h of exposure to essential oil va- height, 8 cm diameter) with wheat fl our at pours, the insects were transferred to plastic 26 ± 1 °C, 65 ± 5% r.h. and a photoperiod of Petri dishes containing wheat fl our. All dead 12 h light, 12 h dark. insects were counted by the fourth day, except pupae which were kept for a further Isolation of essential oils 4 days, with those that failed to complete Essential oils were obtained by subject- morphogenesis and/or produced developing plant materials to hydrodistillation using mental intermediates or ‘adultoids’ (pupal-

© Benaki Phytopathological Institute Toxicity of essential oils against Tribolium confusum 31 adult mosaics) being counted as dead. Also increasing age was recorded, with females the larvae that survived the tests were kept being more tolerant than males, especially until pupation to examine possible delayed for 60-day-old adults, where the observed mortality or morphological deformations. diff erences were statistically signifi cant. Four to seven doses were tested for each The most susceptible stage to the va- essential oil and developmental stage com- pours of L. nobilis oil was that of the 10-day- bination. Each dose was repeated three or old larvae, and the most tolerant that of the four times. Due to diff erential toxicity, dos- 25-day-old larvae (Table 2). In the case of pu- es of the compounds tested ranged from pae, males were more susceptible than fe- 0.27 to 165 μl/l of air depending on the es- males to the essential oil vapours. Also, adult sential oil, insect developmental stage, age susceptibility to the vapours decreased with and sex (based on preliminary tests). All ex- increasing age, but no signifi cant diff erenc- periments were carried out in an incubator es between the sexes were observed. at 26 ± 1°C, 65 ± 5% r.h. and 12 h light/12 h The10-day-old larvae were the most vul- dark photoperiod. nerable to the vapours of T. orientalis oil, followed by pupae and adults (Table 3). Nev-

Statistical analysis ertheless, the calculated LC50 values for all Data obtained from each dose-response stages (except those for the young larvae) bioassay were subjected to probit analy- could not provide a clear picture of the de- sis and LC50 values and 95% confi dence lim- gree of susceptibility because in most cases its were estimated. The comparisons among the statistical analysis did not reveal signifi -

LC50 values were based on the overlap of cant diff erences. confi dence limits (Finney, 1971). All analyses A similar case to the T. orientalis oil was were conducted using the statistical pack- recorded for C. sinensis and C. limon, with age SPSS 14.0 (SPSS, 2004) young larvae being more susceptible than older ones (Tables 4 and 5). A slight (but not statistically signifi cant) decrease in suscepti- Results bility of adults to the citrus essential oil vapours with increasing age was observed. Fumigant toxicity of essential oils The essential oil of O. vulgare showed a

The fumigant toxicity (LC50 values) of the completely diff erent eff ect from all the oth- essential oils of L. hybrida, L. nobilis, T. ori- er essential oils tested. In fact, with the ex- entalis, C. sinensis, C. limon and O. vulgare ception of 10-day-old larvae and pupae, its against immature and adult T. confusum is vapours did not provoke mortality even at given in Tables 1, 2, 3, 4, 5 and 6, respective- doses up to 165 μl/l air (Table 6). ly. All but O. vulgare essential oils exhibited strong fumigant toxicity to all developmen- Eff ect on surviving larvae tal stages of T. confusum. LC50 values ranged The larvae that survived exposure to es- between 1.8 and 109 μl/l air depending on sential oils did not exhibit any noticeable the essential oil and insect developmental delayed mortality or any kind of morpho- stage, age and sex. logical abnormalities (data not shown). The most susceptible stage of T. confusum to the vapours of L. hybrida essential oil Eff ect on pupae was the 10-day-old larvae (LC50, 1.8 μl/l air), All the essential oils tested caused a while the most tolerant was the 31-day-old greater or lesser proportion of deformations larvae (LC50 109.9 μl/l air) (Table 1). The esti- in T. confusum pupae. These morphological mated LC50 values for female and male pu- deformations were noted in both males and pae were very close (37.3 and 38.7 μl/l air, females, with pupae trapped in the pupari- respectively). An increase in the adults’ sus- um, individuals with an appearance interme- ceptibility to the essential oil vapours with diate between pupae and adults (adultoids),

Table 1. Fumigant toxicity of Lavandula hybrida essential oil to larvae, pupae and adults of Tribolium confusum.

1 2 2 Life stage (n ) slope ± SE LC50 95% CL df χ Larvae 10-day-old (420) 0.7 ± 0.1 1.8 1.2 - 2.9 5 4.6 25-day-old (300) 3.6 ± 1.1 59.7 49.9 - 108.3 3 0.9 31-day-old (240) 2.2 ± 0.6 109.9 89.0 - 159.6 2 4.5 Pupae Females (300) 3.3 ± 0.5 37.3 32.9 - 42.7 3 3.2 Males (300) 4.2 ± 0.6 38.7 35.0 - 43.2 3 4.8 Adults 10-day-old Females (320) 3.9 ± 0.6 81.0 71.1 - 98.6 3 2.1 Males (300) 4.6 ± 0.7 61.0 54.1 - 73.1 3 7.43 Adults 60-day-old Females (240) 8.0 ± 1.2 46.3 41.9 - 51.7 2 0.7 Males (280) 6.6 ± 1.0 29.8 25.8 - 34.4 2 2.7 1 Number of insects tested. 2 LC50 values are expressed as μl/l air and are considered signifi cantly diff erent when the 95% confi dence limits (CL) fail to overlap. 3 Since the goodness-of-fi t test is signifi cant (P<0.1), a heterogeneity factor is used in the calculation of confi dence limits (CL).

Table 2. Fumigant toxicity of Laurus nobilis essential oil to larvae, pupae, and adults of Tribo- lium confusum.

1 2 2 Life stage (n )slope±SELC50 95% CL df χ Larvae 10-day-old (240) 0.3 ± 0.5 18.6 15.8 - 21.1 2 3.1 25-day-old (360) 8.8 ± 0.9 86.9 70.3 - 120.3 4 30.43 31- day-old (360) 1.7 ± 0.5 55.6 37.9 - 66.8 4 2.1 Pupae Females (240) 4.0 ± 0.7 42.6 38.7 - 48.5 2 0.1 Males (240) 4.9 ± 0.6 33.7 30.5 - 36.7 2 2.3 Adults 10-day-old Females (240) 10.9 ± 1.5 62.7 60.3 - 65.0 2 5.8 Males (240) 7.2 ± 0.9 57.8 54.4 - 61.2 2 2.6 Adults 60-day-old Females (240) 14.0 ± 1.4 40.5 38.9 - 42.2 2 5.4 Males (280) 14.0 ± 1.4 40.5 38.9 - 42.2 2 5.4 1 Number of insects tested. 2 LC50 values are expressed as μl/l air and are considered signifi cantly diff erent when the 95% confi dence limits (CL) fail to overlap. 3 Since the goodness-of-fi t test is signifi cant (P<0.1), a heterogeneity factor is used in the calculation of confi dence limits (CL).

Table 3. Fumigant toxicity of Thuja orientalis essential oil to larvae, pupae, and adults of Tri- bolium confusum.

2 2 Life stage (n1) slope ± SE LC50 95% CL df χ Larvae 10-day-old (240) 2.0 ± 0.3 20.8 17.0 - 26.2 2 0.2 25-day-old (360) 5.5 ± 0.6 99.2 74.7 - 140.0 4 27.13 31-day-old (300) 7.0 ± 0.7 96.0 90.8 - 102.5 3 2.6 Pupae Females (480) 4.3 ± 0.8 66.9 57.5 - 94.6 6 18.93 Males (480) 8.5 ± 0.9 52.0 46.5 - 64.2 6 39.63 Adults 10-day-old Females (300) 13.6 ± 1.4 64.6 55.1 - 88.7 3 19.33 Males (300) 12.4 ± 1.4 54.3 52.4 - 57.0 3 3.2 Adults 60-day-old Females (240) 9.7 ± 1.1 73.6 70.5 - 76.8 2 4.7 Males (360) 10.0 ± 1.0 53.6 49.7 - 60.7 4 10.63 1 Number of insects tested. 2 LC50 values are expressed as μl/l air and are considered signifi cantly diff erent when the 95% confi dence limits (CL) fail to overlap. 3 Since the goodness-of-fi t test is signifi cant (P<0.1), a heterogeneity factor is used in the calculation of confi dence limits (CL).

Table 4. Fumigant toxicity of Citrus sinensis essential oil to larvae, pupae and adults of Tribo- lium confusum.

1 2 2 Life stage (n ) slope ± SE LC50 95% CL df χ Larvae 10-day-old (240) 2.0 ± 0.3 19.0 12.3 – 35.6 2 8.83 25-day-old (240) 13.0 ± 1.7 104.5 100.4 - 108.0 2 5.9 31-day-old (300) 4.3 ± 0.5 79.6 45.1 - 105.5 3 11.23 Pupae Females (300) 7.8 ± 0.8 42.3 26.8 - 54.9 3 18.13 Males (240) 3.5 ± 0.8 39.4 35.3 - 45.0 2 2.8 Adults 10-day-old Females (320) 18.0 ± 2.2 33.1 30.3 - 38.8 3 12.63 Males (240) 20.8 ± 2.4 30.8 22.5 - 36.0 2 6.8 Adults 60-day-old Females (240) 10.3 ± 1.2 29.2 28.0 - 30.5 2 2.13 Males (360) 16.6 ± 1.7 27.8 26.2 - 30.3 4 14.73 1 Number of insects tested. 2 LC50 values are expressed as μl/l air and are considered signifi cantly diff erent when the 95% confi dence limits (CL) fail to overlap. 3 Since the goodness-of-fi t test is signifi cant (P<0.1), a heterogeneity factor is used in the calculation of confi dence limits (CL).

Table 5. Fumigant toxicity of Citrus limon essential oil to larvae, pupae, and adults of Tribo- lium confusum.

1 2 2 Life stage (n ) slope ± SE LC50 95% CL df χ Larvae 10-day-old (240) 4.3 ± 0.5 21.5 12.0 - 51.7 2 5.53 25-day-old (240) 0.03 ± 0.01 77.2 71.7 - 82.5 2 3.23 31-day-old (300) 4.1 ± 0.57 85.0 78.0 - 92.9 3 7.2 Pupae Females (240) 0.06 ± 0.01 51.3 48.4 - 54.4 2 2.1 Males (300) 7.0 ± 0.8 45.1 27.2 - 69.9 3 18.83 Adults 10-day-old Females (340) 0.2 ± 0.02 35.5 31.9 - 39.5 3 12.53 Males (240) 0.2 ± 0.02 33.7 32.5 - 34.8 2 2.0 Adults 60-day-old Females (240) 0.2 ± 0.02 31.9 26.3 - 35.9 2 4.0 Males (240) 0.3 ± 0.03 28.5 27.6 - 29.4 2 3.2 1 Number of insects tested. 2 LC50 values are expressed as μl/l air and are considered signifi cantly diff erent when the 95% confi dence limits (CL) fail to overlap. 3 Since the goodness-of-fi t test is signifi cant (P<0.1), a heterogeneity factor is used in the calculation of confi dence limits (CL).

Table 6. Fumigant toxicity of Origanum vulgare essential oil to larvae, pupae and adults of Tribolium confusum.

1 2 2 Life stage (n ) slope ± SE LC50 95% f.l. df χ Larvae 10-day-old (300) 1.0 ± 0.2 25.6 18.1 - 41.3 3 3.8 25-day-old (120) - >1653 --- 31-day-old (120) - >1653 --- Pupae Females (300) 4.0 ± 0.5 74.8 68.1 - 83.7 3 3.5 Males (300) 2.5 ± 0.4 73.0 63.7 - 84.5 3 3.2 Adults 10-day-old Females (120) - >1653 --- Males (120) - >1653 --- Adults 60-day-old Females (120) - >1653 --- Males (120) - >1653 --- 1 Number of insects tested. 2 LC50 values are expressed as μl/l air and are considered signifi cantly diff erent when the 95% confi dence limits (CL) fail to overlap. 3 Indicates the higher dose tested, oregano essential oil vapour failed to provoke mortality even at doses up to 165 μl/l air.

© Benaki Phytopathological Institute Toxicity of essential oils against Tribolium confusum 35 adults with malformed elytra and morpho- Discussion and Conclusions logical deformities ranging from aberration of the tarsi to legs reduced to stump-like ap- The essential oil vapours of L. hybrida, L. no- pendages. For all essential oils, the propor- bilis, T. orientalis, C. sinensis and C. limon ex- tion of the pupae trapped in the puparium hibited a strong toxic action against the im- was less than that of the adultoids, with the mature stages and adults of T. confusum. The exception of L. hybrida, where high doses fumigant toxicity of these essential oils de- had the opposite eff ect (Fig. 1). pended on the insect developmental stage.

Fig.1. Eff ects of essential oil vapours on pupae of Tribolium confusum.

© Benaki Phytopathological Institute 36 Theou et al. i.e. L. hybrida showed the highest toxic eff ect Essential oils of L. nobilis from various or- against 10 and 25 day-old larvae, L. nobilis igins were found to be also eff ective against was the most toxic for 31 day-old larvae and adults of T. castaneum, but the LC50 values C. sinensis and C. limon were the most toxic reported (ranged from 172 to 217 μl/l air) for adults. Lemon and orange essential oils were much higher than the present one cal- are particularly rich in limonene (Giatropou- culated for the adults of T. confusum (Jemâa los et al., 2012) which was found to be one et al., 2012). Nevertheless, the O. vulgare es- of the most toxic compounds among other sential oil vapours have been found to be a monoterpenes against adults of T. confusum highly eff ective fumigant against the adults

(Stamopoulos et al., 2007). of T. castaneum with LC50 value of 55 mg/l air Origanum vulgare essential oil vapours, (Kim et al., 2010). These results are indicative with the exception of 10-day-old larvae and of the highly idiosyncratic toxicity of individ- pupae, failed to result in mortality even at ual oils even between closely related species doses up to 165 μl/l air. Our results concern- such as T. confusum and T. castaneum. ing O. vulgare essential oil, are in correlation Susceptibility of adults to the essential with those obtained by Demirel et al. (2009) oils seems to increase with the adult’s age, which demonstrated that O. vulgare, O. on- even though this is not statistically proved ites L. and O. minutifl orum L. essential oils in most cases. Older insects tend to be more possessed the weakest toxicity among eight vulnerable to the essential oil vapours, per- diff erent essential oils evaluated against T. haps because they are less able to metabo- confusum. lise and/or detoxify these substances. According to our fi ndings, tolerance to In all but one case (L. hybrida), male pu- the essential oils increases as the immature pae seem to be relatively more susceptible stages grow older, which coincides with ex- than female pupae although, in most cases, posure data of T. confusum larvae to some the recorded diff erences were not statisti- monoterpenes (Stamopoulos et al. 2007) as cally signifi cant. Similar slight sex diff erenc- well as data of T. castaneum and Acanthos- es in susceptibility were also observed in the celides obtectus (Say) larvae to various essen- adult stage. These diff erences could be con- tial oil vapours (Huang et al., 1997; Liu and sistent with an innate diff erence in mode of Ho, 1999; Papachristos and Stamopoulos, action rather than with size, especially as 2002). A possible explanation is that the ex- the diff erence in size between males and isting diff erence in body size may be respon- females of T. confusum is almost negligible sible for the variations in susceptibility. and cannot justify the divergence in suscep- The L. hybrida, L. nobilis, C. sinensis and C. tibility observed in other stored product in- limon essential oils, in their vapour form, are sects (Papachristos and Stamopoulos, 2002; known to be eff ective against other stored Papachristos et al., 2004). product insect pests. Essential oils from L. The derailing of morphogenesis at the hybrida, L. nobilis and C. sinensis are eff ective pupal stage and the appearance of adul- against the bean weevil A. obtectus (Papach- toids and mutilated adults could be ex- ristos and Stamopoulos, 2002; Papachristos plained by assuming a direct eff ect on the et al., 2004) and essential oils of C. sinensis insect hormonal system similar to that of and C. limon are eff ective against adults and the insect growth regulators (IGRs). Accord- larvae of Callosobruchus maculates F., Sitophi- ing to the literature, L. nobilis essential oil lus zeamais Motsch. and Dermestes maculatus contains high amounts of 1,8 cineole (Me- Deg. (Don-Pedro, 1996). In all these cases, the diouni et al., 2012) and that of L. hybrida con-

LC50 values of essential oils were much lower tains 1,8 cineole and linalool (Papachristos from the one calculated for T. confusum in the et al., 2004). Lemon and orange essential present work indicating lower susceptibility oils consist almost of limonene (Giatropou- of T. confusum to essential oil vapours com- los et al., 2012) and the eff ects of these es- pared to other stored product insect pests. sential oils on T. confusum pupae morpho-

© Benaki Phytopathological Institute Toxicity of essential oils against Tribolium confusum 37 genesis could be attributed to the action of en that the mechanisms underlying the ap- some of their monoterpnenes components. pearance of adultoids and mutilated adults Such potent action on pupal morphogene- have been, to the best of our knowledge, in- sis has been demonstrated after exposure of adequately studied. T. confusum pupae to some monoterpenes Overall, essential oils tested with the ex- (terpinen-4-ol, 1,8-cineole, linalool, R-(+)-li- ception of O. vulgare essential oil were high- monene and geraniol) (Stamopoulos et al., ly toxic against larvae, pupae and adults of 2007). Moreover, some citrus essential oils T. confusum indicating the potential of their (lemon, sweet orange and grape fruit) ap- possible utilization as fumigants in protec- plied against the late third- and early fourth- tion of stored products in storehouses by instar larvae of Aedes (Stegomyia) albopic- reducing the risks associated with the use tus (Skuse 1894), the so-called “Asian tiger of synthetic insecticides. However, many mosquito”, produced insect growth regula- aspects of their release kinetics after ap- tor (IGR)-like properties (Giatropoulos et al., plication and the eff ect of factors such as 2012). Such eff ects were also observed by temperature, relative humidity and stored Amos et al. (1974) after incorporating various product commodities, must be studied to terpenoids into the diet of T. castaneum and determine whether these substances can T. confusum, and by other authors working be realistically applied as fumigants against with hydroprene (Bell and Edwards, 1999; stored-product insects in practice. Arthur, 2003; Arthur and Dowdy, 2003) Contrary to what observed for pupae, the larvae that survived the toxicity tests Literature Cited and were kept until pupation to examine possible delayed mortality or morphologi- Aitken, A.D. 1975. Insect travelers I: Coleoptera. Tech- nical Bulletin 31. London: HMSO, 190 p cal deformations did not exhibit such abnor- Amos, T.G., Williams, P., Du Guesclin, P.B. and malities. It is known that some terpenoids Schwarz, M. 1974. Compounds related to juve- display activity similar to that exerted by the nile hormone: Activity of selected terpenoids Juvenile Hormone analogues, when larvae on Tribolium castaneum and Tribolium confusum. of insects are subjected to their vapours for Journal of Economic Entomology, 67:474-476. a long time, performing extra moults and fi - Arthur, F.H. 2003. Effi cacy of a volatile formulation of hydroprene (Pointsourcet) to control Tribolium nally developing into either larval-pupal in- castaneum and Tribolium confusum (Coleoptera: termediates or normal pupae which pro- Tenebrionidae). Journal of Stored Products Re- duce both morphologically normal adults search, 39: 205–212. and adultoids (Amos et al., 1974; Semple, Arthur, F.H. and Dowdy, A.K. 2003. Impact of high 1992). Two likely explanations can be adopt- temperatures on effi cacy of cyfl uthrin and hydroprene applied to concrete to control Tribo- ed here: either the toxicity tests’ limited ex- lium castaneum (Herbst). Journal of Stored Prod- posure time (48h) was insuffi cient for the ucts Research, 39: 193–204. expression of the aforementioned phenom- Bell, H.A. and Edwards, J.P. 1999. The activity of (S)- ena or, as Semple (1992) reports, ‘larvae of hydroprene space spray against three stored most holometabolous insects such as Lepi- products pests in a simulated food production environment. Journal of Stored Products Re- doptera and Coleoptera are susceptible only search, 35: 117-126. at the end of the last larval instar, while the Boyer S. Zhangand H. and Lempérière G. 2012 A re- pupae are susceptible for several hours or at view of control methods and resistance mecha- most a few days after the last larval ecdysis’. nisms in stored-product insects. Bulletin of Ento- Although our fi ndings are preliminary, mological Research, 102: 213-229. they could form a basis for further investiga- Dansi, L., Van Velson F.L. and Vander Heuden C.A. 1984. Methyl bromide: carcinogenic eff ects in tion of the questions raised in this work. In the rat fore stomach. Toxicological and Applied particular, additional research is needed to Pharmacology, 72: 262-271. improve our understanding of how essential Demirel, N., Sener, O., Arslan, M., Uremıs, I., Uluc, oil vapours act during morphogenesis, giv- F.T. and Cabuk, F. 2009. Toxicological respons-

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Τοξικότητα των ατμών έξι αιθέριων ελαίων σε ανήλικα και ενήλικα άτομα του είδους Tribolium confusum

Γ. Θέου, Δ.Π. Παπαχρήστος και Δ.Κ. Σταμόπουλος

Περίληψη Προσδιορίστηκε η τοξικότητα των ατμών έξι αιθέριων ελαίων (Lavandula hybrida, Laurus nobilis, Thuja orientalis, Citrus sinensis, Citrus limon, και Origanum vulgare) σε προνύμφες, νύμφες και ενήλικα του είδους Tribolium confusum. Τα αποτελέσματα έδειξαν ότι όλα τα αιθέρια έλαια, με εξαίρεση αυτό του είδους O. vulgare, ήταν τοξικά για όλα τα στάδια ανάπτυξης του εντόμου. Τη μεγαλύτερη ευ- πάθεια στα αιθέρια έλαια εμφάνισαν οι προνύμφες ηλικίας 10 ημερών ενώ την μικρότερη οι προνύμφες

ηλικίας 25 και 31 ημερών. Οι τιμές των μέσων θανατηφόρων δόσεων (LC50) κυμάνθηκαν από 1,8 έως 109 μl αιθέριου ελαίου ανά l αέρα ανάλογα με το στάδιο ανάπτυξης του εντόμου και το είδος του αιθέ- ριου ελαίου. Η έκθεση των νυμφών στους ατμούς των αιθέριων ελαίων προκάλεσε αναστολή της μορ- φογένεσης και της εμφάνισης φυσιολογικών ενηλίκων εντόμων.

Hellenic Plant Protection Journal 6: 29-39, 2013

Hellenic Plant Protection Journal 6: 41-48, 2013

Interference between silverleaf nightshade (Solanum elaeagnifolium Cav.) and alfalfa (Medicago sativa L.) cultivars

I.S. Travlos*, A. Gatos and P.J. Kanatas

Summary Alfalfa (Medicago sativa L.) is the most widely grown forage legume in Greece and other Mediterranean countries. The successful establishment of the crop is crucial for its overall productivity. Weed infestations are a common problem, especially in spring-seeded alfalfa, with silverleaf nightshade (Solanum elaeagnifolium Cav.) being one of the most noxious weeds. The main objective of the fi eld experiment conducted in Greece in 2010 and 2011 was to evaluate the diff erences among three alfalfa cultivars (Gea, Dimitra and Hyliki) regarding their competitiveness against silverleaf nightshade and their forage yield during the fi rst crucial year of crop establishment. Moreover, density and fresh weight data of S. elaeagnifolium were also recorded. Our results showed that the presence of this weed caused an annual yield loss ranged from 8 to 26%, depending on the year and the cultivar. In particular, Hyliki was the most productive cultivar, while even with the presence of nightshade it produced signifi - cantly higher biomass than the other cultivars (up to 28%). Furthermore, Hyliki was the cultivar with the highest regrowth rate after each cutting. Weed density and biomass were also signifi cantly reduced in the case of Hyliki, while Gea was the less competitive cultivar. The results of the present study confi rm that the competitive ability of the alfalfa cultivars might have a substantial range and can be a helpful weed management tool for the growers, especially against noxious species such as S. elaeagnifolium.

Additional keywords: alfalfa cultivars, integrated weed management, noxious weeds, regrowth, competition

Introduction tablishment and early growth (especially in spring-seeded alfalfa), since the emerging Alfalfa or lucerne (Medicago sativa L.), crop plant is not a vigorous competitor and the most widely grown forage legume weeds emerging shortly after seeding can in Greece, could play a key role in organ- reduce alfalfa productivity (Pike and Stritz- ic crop-livestock systems, owing to its suit- ke, 1984; Fischer et al., 1988; Zimdahl, 2004). ability to low input, rainfed conditions, its The ability of several alfalfa cultivars to sup- positive eff ects on soil fertility and nitrogen press weed growth may allow crop produc- balance, and the high protein content and ers to reduce total costs (Ominski et al., 1999; quality of its forage (Entz et al., 2001; Kara- Arregui et al., 2001; Dillehay et al., 2011). manos et al., 2009). The successful estab- During the last years, there have been lishment of the crop is crucial for its overall complaints from several regions of Greece productivity (Stout et al., 1992). Established for reduced effi cacy of herbicides or in- stands of alfalfa are fairly competitive with creased competitiveness of many alien or weeds. However, new alfalfa seedlings are recently problematic species (Travlos, 2009; less competitive and more susceptible to Travlos and Chachalis, 2010). Silverleaf night- weed invasion (Annicchiarico and Pecet- shade (S. elaeagnifolium Cav.) is one of these ti, 2010). In fact, weed competition is one species, already present for many years in of the most limiting factors during crop es- the country (Economidou and Yannitsaros, 1975), with an ongoing dispersal in Greece especially during the last decade, accord- Laboratory of Agronomy, Faculty of Crop Science, Ag- ing to extensive weed surveys (Travlos et ricultural University of Athens, 75, Iera Odos St., GR- 11855 Athens, Greece al., 2011; Travlos, 2013). Silverleaf nightshade * Corresponding author: [email protected] has spread in many arid regions of the world

(Boyd et al., 1984) and is a deep-rooted, per- and subplot sizes were 6 by 4 m and 2.5 by 4 ennial, broadleaf weed that propagates by m, respectively. seed, root segments, and creeping lateral Irrigation and other common cultural roots (Cuthbertson et al., 1976). Moreover, S. practices were conducted as needed during elaeagnifolium is now considered as a nox- the growing seasons. Mean monthly tem- ious and invasive alien weed, against which perature and rainfall data are given in Ta- international measures have to be taken in ble 1. In each cutting, forage yield was mea- many areas (OEPP/EPPO, 2004). sured, while the total fi rst-year cumulative Quantitative information regarding the yield was also recorded. The dry weight of potential suppressive eff ect of alfalfa culti- forage was determined after oven drying at vars on weeds in current cropping systems 70oC for 48 h. In the same days (65, 100, 145 is rather lacking. Therefore, the objectives of and 210 DAS) measurements of the density this study were to evaluate the diff erences and biomass of silverleaf nightshade were among three alfalfa cultivars (Gea, Dimitra also taken. Visual estimation of regrowth and Hyliki) regarding their competitiveness ability of each cultivar was also conduct- against the noxious weed S. elaeagnifolium ed 15 days after each harvest (cutting) by and their productivity (forage yield) during means of a scale, comparing the most vig- the fi rst year of crop establishment. orous stands (high and dense, scored as 5) with the lowest and fewer plants (scored as 1). Materials and Methods An analysis of variance (ANOVA) was conducted for all data and diff erences be- A fi eld experiment was conducted during tween means were compared at the 5% 2010 (and repeated in 2011) in the exper- level of signifi cance using the Fisher’s Pro- imental fi eld of Agricultural University of tected LSD test. Linear regression was also Athens (37ο 59’ 12’’ N, 23ο 42’ 96’’ E, 29 m alti- performed for the three cultivars relating tude) in order to study the competitive abili- the forage yield and silverleaf nightshade ty of three alfalfa cultivars (Gea, Dimitra and biomass. All statistical analyses were con- Hyliki) against silverleaf nightshade. ducted using the Statistica 9 software pack- The soil was clay loam (Bouyoucos, 1962), age (StatSoft, Inc. 2300 East 14th Street, Tul- with pH 7.29 (1:1 H2O), 15 g/kg organic mat- sa, OK 74104, USA). ter (Wakley and Black, 1934) and 160 g/kg

CaCO3. Hand-sowing took place at the rate of 20 kg/ha on 28 March, 2010 and 23 March, Results and Discussion

2011. The fi eld was fertilized with P2O5 and

K2O as recommended by soil analysis for The analysis of variance of our data revealed alfalfa (Hall, 2008). Alfalfa crop was mown that alfalfa forage yield and silverleaf night- each time it reached 10% bloom. This result- shade growth (density and biomass produced in four harvests each year at 65, 100, 145 tion) were signifi cantly aff ected by the al- and 210 days after sowing (DAS). Rhizomes falfa cultivar and the presence or absence of S. elaeagnifolium (5-6 cm in length) were of the weed. The year was also a signifi cant uniformly planted horizontally (12-15 g/m2 factor for the forage yield of the crop and in a depth of 4-5 cm), while other weed spe- for the density of S. elaeagnifolium plants, cies emerged within the experimental area while it had no signifi cant eff ect on the fresh were removed by hand-hoeing. weight of the weed. Moreover, the interac- The experimental design was a split-plot tion between the above-mentioned factors in a randomized complete block with four was signifi cant for most parameters except blocks (replicates). Alfalfa cultivar was the the biomass of silverleaf nightshade on indi- main plot factor and the weed presence (or vidual plant’s level (Table 2). absence) was the subplot factor. Main plot In particular, the harmful eff ects of silver-

© Benaki Phytopathological Institute Competitiveness of alfalfa cultivars against silverleaf nightshade 43 leaf nightshade on the forage yield of alfalfa 34 and 51-57% lower than the correspond- are shown in Table 3. The presence of S. elae- ing values for Dimitra and Gea, respective- agnifolium was responsible for signifi cant ly. The more rainfalls during 2011 resulted to reductions, up to 26, 15 and 14% in the an- a higher weed density compared with the nual yields of the cultivars Gea, Dimitra and fi rst, drier year of experimentation. Hyliki, respectively. The higher yields of all Concerning the weed biomass, the three alfalfa cultivars during the second year mean growth of individual silverleaf night- of experimentation (2011) compared with shade plants in the plots with Hyliki was 43 the fi rst year (2010) were probably due to and 60% lower than the corresponding val- the signifi cantly higher precipitation (38%) ues for Dimitra and Gea, respectively. Addi- during 2011 (Table 1). It has also to be not- tionally, in the fourth harvest of alfalfa (210 ed that the maximum yield reductions were DAS), the number of S. elaeagnifolium plants observed in the second and third harvest. in the case of Hyliki was 65% lower than that This fi nding may be attributed to the vigor- of Gea, while the fresh weight per plant was ous growth of silverleaf nightshade during also signifi cantly lower (82%), as shown in summer (mostly July and August) and is in Table 5. full accordance with previous studies (Trav- This less vigorous and less dense pres- los, 2012). Our results also proved that even ence of the weed in the plots of Hyliki is prob- in the presence of silverleaf nightshade, the ably due to the recorded faster regrowth annual forage yield of Hyliki was 23 to 28% rate of this cultivar of alfalfa, compared with and 12 to 13% higher than the yield of Gea the other two cultivars. Indeed, according to and Dimitra, respectively. our observations the regrowth ability of Hy- Regarding the density of silverleaf night- liki after each harvest was signifi cantly high- shade, the weed was present at densities er (scored as 4) than the other two cultivars ranging between 2 and 7 plants/m2 in the (scored as 2). It is considered that diff erenc- plots of Gea during the fi rst year, while for es among alfalfa cultivars in their ability to Hyliki the maximum density was only about develop canopy structures early in the sea- 3 plants/m2 (Table 4). The mean density of son could aff ect weed emergence (Huarte the weed plants in the case of Hyliki was 31- and Benech Arnold, 2003). Alfalfa has the

Table 1. Mean monthly rainfall and temperature during the fi eld experiment in 2010 and 2011.

Rainfall Temperature Month 2010 2011 2010 2011 mm °C January - - - - February - - - - March 11 25.6 14.4 12.2 April 0 40 17.9 15.5 May 7 40.8 22.2 20.3 June 12 30.4 25.9 25.5 July 0 0 29.3 29.7 August 0 0.6 28.4 28.8 September 22.6 3.4 24.9 26.6 October 81.8 38.4 19 17.5 November 15.6 2.2 18.4 12.3 December 25 100.8 13.7 12 Total 175 282.2 - -

Table 2. Analysis of variance for alfalfa cultivar (A), presence of Solanum elaeagnifolium (S), and year (Y) eff ects on alfalfa forage yield, density and biomass of the weed plants.

Silverleaf nightshade Silverleaf nightshade Source df Alfalfa forage yield density biomass

A2*** * S 1 ** ** ** A x S 1 * ∗ * Y2** ns Y x A 2 * * ns Y x S 1 * * ns Y x A x S 2 * * ns * Signifi cant at the 0.05 level ** Signifi cant at the 0.01 level

Table 3. Forage yield of three alfalfa cultivars (Gea, Dimitra, Hyliki) (dry weight in tn/ha) with the presence of Solanum elaeagnifolium and under a weed-free situation in a two-year fi eld experiment (2010, 2011). Each number represents the mean yield of a cultivar per cutting or the total mean yield of a cultivar in 2010. In parentheses the corresponding values for 2011 are also shown.

With S. elaeagnifolium Gea Dimitra Hyliki Cuttings Dry weight (tn/ha) 65 DAT 2.84 (3.3) b 3.35 (3.89) a 3.66 (4.04) a 100 DAT 1.88 (2.2) d 2.49 (2.63) cd 2.81 (3.09) c 145 DAT 1.67 (1.88) f 2.21 (2.29) ef 2.58 (2.82) e 210 DAT 2.55 (3.01) h 2.91 (3.04) h 3.36 (3.61) g Total 8.94(10.39) k 10.96 (11.85) j 12.41 (13.56) i Without weeds Gea Dimitra Hyliki Cuttings Dry weight (tn/ha) 65 DAT 3.72 (3.98) m 4.36 (4.14) l 4.21 (4.29) l 100 DAT 2.66 (2.82) o 2.97 (3.13) no 3.52 (3.38) n 145 DAT 2.35 (2.42) q 2.43 (2.77) q 3.05 (3.25) p 210 DAT 3.38 (3.44) rs 3.15 (3.3) s 3.71 (3.82) r Total 12.11 (12.66) u 12.91 (13.34) tu 14.49 (14.74) t Means within a row followed by the same letter are not signifi cantly diff erent (p < 0.05) according to Fischer’s LSD test.

Table 4. Density of Solanum elaeagnifolium plants in plots of three alfalfa cultivars (Gea, Dimitra, Hyliki) in a two-year experimental fi eld (2010, 2011). Each number represents the mean number of weed plants for an alfalfa cultivar per cutting or the total mean number of weed plants for each cultivar in 2010. In parentheses the corresponding values for 2011 are also shown.

Density of S. elaeagnifolium (plants/m2) Cuttings Gea Dimitra Hyliki 65 DAT 2.2 (3.1) a 1.2 (2.1) b 1.3 (2.1) b 100 DAT 5.3 (7.2) c 2 (3.6) d 2.2 (3.4) d 145 DAT 7.1 (7.4) e 5.2 (4.5) e 3 (3.1) f 210 DAT 3.4 (4.1) g 3.3 (5.4) g 1.2 (2.1) h Mean 4.5 (5.45) i 2.9 (3.9) ij 1.9 (2.7) j

Means within a row followed by the same letter are not signifi cantly diff erent (p < 0.05) according to Fischer’s LSD test.

Table 5. Biomass of Solanum elaeagnifolium plants (fresh weight in g/plant) in plots of three alfalfa cultivars (Gea, Dimitra, Hyliki) in a two-year experimental fi eld (2010, 2011). Each number represents the mean fresh weight of weeds for a cultivar per cutting in both experimental years or the total mean fresh weight of weeds for each cultivar.

Fresh weight of S. elaeagnifolium (g/plant) Cuttings Gea Dimitra Hyliki 65 DAT 2.3 a 2.6 a 2.4 a 100 DAT 9.8 b 6.4 c 5.2 c 145 DAT 12.4 d 8.4 e 4.8 f 210 DAT 11.9 g 8.6 g 2.2 h Mean 9.1 i 6.5 j 3.7 k Means within a row followed by the same letter are not signifi cantly diff erent (p < 0.05) according to Fischer’s LSD test. ability to suppress weed growth (Peters and this study (Fig. 1) suggests that maintaining Linscott 1988) and appears to exert a long- a high crop biomass is important to avoid term eff ect on weed population dynamics the invasion of the silverleaf nightshade and (Ominski et al., 1999). Several weeds are ex- this is in full accordance with previous stud- pected to be eff ectively suppressed by M. ies showing a similar relationship between sativa, and thus including alfalfa in crop ro- alfalfa and weeds (Grewal, 2010). Moreover, tations regime can be part of an integrat- it could be said that the greater suppression ed weed management strategy for weeds of silverleaf nightshade in the case of Hyliki such as Avena fatua, Brassica kaber, Cirsium was partly due to the high productivity of arvense, Rumex crispus, Amaranthus quitensis this specifi c cultivar as previously shown in (Ominski et al. 1999; Huarte and Benech Ar- the weed-free situation in Table 3. nold, 2003). In moderate to severe weed infestations, The inverse linear relationship (R2 be- alfalfa yield can be reduced through compe- tween 0.72 and 0.83) between alfalfa forage tition for light, water, and nutrients and the yield and S. elaeagnifolium biomass found in forage quality can be lowered by decrease

Figure 1. Relationship between forage yield of alfalfa and biomass of Solanum elaeagnifolium for three alfalfa cultivars (Gea, Dimitra, Hyliki) and four harvests during the fi rst year of crop establishment. in digestibility and protein content of the during the establishment year reduces stress alfalfa hay (Cords 1973). Usually, alfalfa and on alfalfa and ultimately increases yield in weeds are harvested together and thus the the following years (Stout et al., 1992; Trav- quality of the hay is signifi cantly degraded. los, 2011). Consequently, the careful selec- This degradation is even higher, especially tion of the most productive and weed com- in the case of weeds such as silverleaf night- petitive alfalfa cultivars could be of great shade that animals are reluctant to graze be- importance during the crucial year of crop cause of the spiny leaves and stems (David et establishment. al., 1945). For the eff ective control of silverleaf nightshade, several mechanical (David et al., 1945), biological (Keeling and Aber- Conclusions nathy, 1980; Parker, 1986), or chemical methods (Philips and Merkle, 1980; Eleftherohori- Our results showed that the weed compet- nos et al., 1993; Westerman and Murray, 1994) itive ability and forage yield of alfalfa cul- have been proposed. However, an integrat- tivars might have a substantial range and ed weed management approach based on a should be certainly taken into account. An- rotation regime with competitive alfalfa cul- nual forage yield loss in the case of less tivars is rather required for an eff ective con- weed competitive alfalfa cultivars was high trol of noxious species, such as silver night- and up to 26%, while after the selection of shade. the most productive and competitive cul- Another critical thing to be taken into ac- tivar (i.e. Hyliki) the reduction was signifi - count is that for a perennial crop like alfal- cantly lower and forage yield could be up to fa, high weed populations in the fi rst year 28% higher, even with the presence of the may adversely aff ect crop yield and quali- noxious silverleaf nightshade. Similar stud- ty in subsequent years (Smith et al., 1990). It ies should be continued including diff er- is well documented that controlling weeds ent alfalfa cultivars, soil and climatic condi-

© Benaki Phytopathological Institute Competitiveness of alfalfa cultivars against silverleaf nightshade 47 tions, weed species and weed densities. The ic farms in the eastern portion of the northern ability of alfalfa to suppress weed growth Great Plains. Can. J. Plant Sci., 81: 351-354. can provide a viable alternative to chemical Fischer, A.J., Dawson, J.H. and Appleby, A.P. 1988. In- terference of annual weeds in seedling alfalfa weed control and allow crop producers to (Medicago sativa). Weed Sci., 36: 583-588. reduce herbicide inputs. Moreover, our re- Grewal, H.S. Fertiliser management for higher pro- sults highlight the underestimated impor- ductivity of established Lucerne pasture. New tance of alfalfa cultivar selection for a suc- Zeal. J. Agric. Res., 53: 303-314. cessful establishment of the crop being also Hall, M.H. 2008. Forages. In Kirsten, A. (ed.) The eff ective against noxious weeds. This is im- Agronomy Guide 2009-2010, #AGRS-026. Univer- portant, especially in cases of organic agri- sity Park, PA: Penn State University, p. 87-108. Huarte, H.R. and Benech Arnold, R.L. 2003. Under- culture and in any other agricultural situa- standing mechanisms of reduced annual weed tions where herbicides are missing or they emergence in alfalfa. Weed Sci., 51: 876-885. should not be applied. Karamanos, A.J., Papastylianou, P.T., Stavrou, J. and Avgoulas, C. 2009. Eff ects of water shortage and air temperature on seed yield and seed performance of lucerne (Medicago sativa L.) in Literature cited a Mediterranean environment. J. Agronomy & Crop Sci., 195: 408-419. Annicchiarico, P. and Pecetti, L. 2010. Forage and Keeling, J.W. and Abernathy, J.R. 1980. Rope appli- seed yield response of lucerne cultivars to cation of herbicides to perennial weeds. Proc. chemically weeded and non-weeded manage- South. Weed Sci. Soc., 33: 357. ments ad implications for germplasm choice in organic farming. Europ. J. Agron., 33: 74-80. OEPP/EPPO (European Plant Protection Organiza- tion). 2004. Invasive alien plants in the EPPO re- Arregui, M.C., Sanchez, D. and Scotta, R. 2001. Weed gion (2004/040). Reporting service no. 3. Paris, control in established alfalfa (Medicago sativa) France. with postemergence herbicides. Weed Technol., 15: 424-428. Ominski, P.D., Entz, M.H. and Kendel, N. 1999. Weed suppression by Medicago sativa in subsequent Bouyoucos, G.J. 1962. Hydrometer method im- cereal crops: a comparative survey. Weed Sci., 47: proved for making particle size analyses of soils. 282-290. Agron. J., 54: 464-465. Parker, P.E. 1986. Nematode control of silverleaf Boyd, J.W., Murray, D.S. and Tyrl, R.J. 1984. Silver- nightshade (Solanum elaegnifolium), a biologi- leaf Nightshade (Solanum elaeagnifolium), ori- cal control project. Weed Sci., 34: 33-34. gin, distribution, and relation to man. Econ. Bot., 38: 210-217. Peters, E.J. and Linscott, D.L. 1988. Weed and weeds control. In Hanson, A.A. et al. (eds.). Alfalfa and Cords, H.P. 1973. Weeds and alfalfa hay quality. Weed Alfalfa Improvement. Agronomy Monograph No. Sci., 21: 400-401. 29. Madison, WI: American Society of Agrono- Cuthbertson, E.G., Leys, A.R. and McMaster, G. 1976. my, p. 705-735. Silverleaf nightshade–a potential threat to agri- Philips, M.W. and Merkle, M.G. 1980. Control of sil- culture. Agric. Gaz. (New South Wales), 87: 11-13. verleaf nightshade using S-734, fl uridone, trifl u- David, C.H., Smith, T.J. and Hawkins, R.S. 1945. Eradi- ralin and glyphosate. Proc. South. Weed Sci. Soc. cation of the white horse-nettle in southern Ar- 33: 184. izona. University of Arizona, Agric. Exp. Stn. Bull. Pike, D.R. and Stritzke, J.F. 1984. Alfalfa (Medicago No. 195. sativa)–cheat (Bromus secalinus) competition. Dillehay, B.L., Curran, W.S. and Mortensen, D.A. 2011. Weed Sci. 32: 751-756. Critical period for weed control in alfalfa. Weed Smith, B.S., Pawlak, J.A., Murray, D.S., Verhalen, L.M. Sci., 59: 68-75. and Green, J.D. 1990. Interference from estab- Economidou, E. and Yannitsaros, A. 1975. Recher- lished stands of silverleaf nightshade (Solanum ches sur la fl ore adventice de Grece. III. Morpho- elaeagnifoium) on cotton (Gossypium hirsutum) logie, development, et phenologie du Solanum lint yield. Weed Sci. 38: 129-133. elaeagnifolium. Candollea, 30: 29-41. Stout, W.L., Byers, R.A., Leath, K.T., Bahler, C.C. and Eleftherohorinos, I.G., Bell, C.E. and Kotoula-Syka, Hoff man, L.D. 1992. Eff ects of weed and inver- E. 1993. Silverleaf nightshade (Solanum elaeag- tebrate control on alfalfa establishment in oat nifolium) control with foliar herbicides. Weed stubble. J. Prod. Agric., 5: 349-352. Technol., 7: 808-811. Travlos, I.S. 2009. Seed germination of several inva- Entz, M.H., Guilford, R. and Gulden, R. 2001. Crop sive species potentially useful for biomass pro- yield and soil nutrient status on 14 organ- duction or revegetation purposes under sem-

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Αλληλεπιδράσεις μεταξύ του ζιζανίου σολανό (Solanum elaeagnifolium Cav.) και τριών ποικιλιών μηδικής (Medicago sativa L.)

Η.Σ. Τραυλός, Α. Γάτος και Π.Ι. Κανάτας

Περίληψη Σε συνθήκες αγρού διερευνήθηκε ο ανταγωνισμός μεταξύ τριών ποικιλιών μηδικής (Medicago sativa L.) και του ζιζανίου Solanum elaeagnifolium Cav. Συγκεκριμένα, στον αγρό του Ερ- γαστηρίου Γεωργίας του Γ.Π.Α. έγινε πειραματισμός για δύο συνεχή έτη (2010, 2011) με τρεις ποικιλί- ες μηδικής (Gea, Δήμητρα, Υλίκη). Ίση ποσότητα ριζωμάτων του ζιζανίου ενσωματώθηκε ομοιόμορφα σε κάθε πειραματικό τεμάχιο, ενώ υπήρχαν και πειραματικά τεμάχια χωρίς την παρουσία του ζιζανίου (μάρτυρας). Μελετήθηκε η απόδοση των τριών ποικιλιών κατά τη διάρκεια των τεσσάρων κοπών για το κάθε έτος πειραματισμού, ενώ παράλληλα λαμβάνονταν μετρήσεις της πυκνότητας και του νωπού βάρους και του σολανού. Τα αποτελέσματα έδειξαν ότι το συνολικό ξηρό βάρος της παραγόμενης βι- ομάζας των ποικιλιών της μηδικής ανά έτος μειώθηκε παρουσία του ζιζανίου S. elaeagnifolium σε σχέ- ση με τους μάρτυρες από 8 έως 26% και ανάλογα με τη χρονιά και την καλλιεργούμενη ποικιλία. Από τις τρεις ποικιλίες η Υλίκη ήταν η περισσότερο παραγωγική ακόμη και σε συνθήκες παρουσίας του σο- λανού με απόδοση σημαντικά υψηλότερη από τις άλλες. Η Υλίκη ήταν επίσης η ποικιλία με τον υψηλό- τερο ρυθμό αναβλάστησης μετά από κάθε κοπή. Επιπλέον, τα αποτελέσματα έδειξαν ότι η πυκνότη- τα και το νωπό βάρος του ζιζανίου ήταν σημαντικά μικρότερα στα πειραματικά τεμάχια της Υλίκης σε σχέση με τα αντίστοιχα της Gea. Η μελέτη αυτή επιβεβαιώνει τις διαφορές ως προς την ανταγωνιστική ικανότητα των ποικιλιών της μηδικής έναντι των ζιζανίων και τη σημασία της σωστής επιλογής της κα- τάλληλης ποικιλίας για την επιτυχή διαχείριση δυσεξόντωτων ζιζανίων όπως το σολανό, ιδιαίτερα μά- λιστα σε βιολογικές καλλιέργειες.

Hellenic Plant Protection Journal 6: 41-48, 2013

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M.R. Karajeh και F.M. Al-Nasir Αποτελεσματικότητα των ανόργανων αλάτων αζώτου στην αντιμετώπιση του νηματώδη Meloidogyne javanica στην τομάτα 19-27

Γ. Θέου, Δ.Π. Παπαχρήστος και Δ.Κ. Σταμόπουλος Τοξικότητα των ατμών έξι αιθέριων ελαίων σε ανήλικα και ενήλικα άτομα του είδους Tribolium confusum 29-39

Η.Σ. Τραυλός, Α. Γάτος και Π.Ι. Κανάτας Αλληλεπιδράσεις μεταξύ του ζιζανίου σολανό (Solanum elaeagnifolium Cav.) και τριών ποικιλιών μηδικής (Medicago sativa L.) 41-48

Hellenic Plant Protection Journal www.bpi.gr © Benaki Phytopathological Institute Volume 6, Issue 1, January 2013 ISSN 1791-3691

Contents H Hellenic Plant Protection Journal e l l e E.V. Kapaxidi n Eriophyoid mites (Acari: Eriophyoidea) in Greek orchards and i

grapevine: A review 1-18 c

M.R. Karajeh and F.M. Al-Nasir P

Ability of nitrogen containing salts to control the root-knot l a nematode (Meloidogyne javanica) on tomato 19-27 n

G. Theou, D.P. Papachristos and D.C. Stamopoulos t

Fumigant toxicity of six essential oils to the immature P

stages and adults of Tribolium confusum 29-39 r o

I.S. Travlos, A. Gatos and P.J. Kanatas t

Interference between silverleaf nightshade (Solanum e

elaeagnifolium Cav.) and alfalfa (Medicago sativa L.) cultivars 41-48 c t i o n

J o u r n a l