First Report of Eriococcus ironsidei Williams (: Coccomorpha: Eriococcidae) on (Macadamia integrifolia Maiden & Betche and Macadamia tetraphylla Johnson: Proteaceae) in South Africa Author(s): P.S. Schoeman & I.M. Millar Source: African Entomology, 26(1):247-249. Published By: Entomological Society of Southern Africa URL: http://www.bioone.org/doi/full/10.4001/003.026.0247

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BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. First report of Eriococcus ironsidei Williams (Hemiptera: Coccomorpha: Eriococcidae) on macadamia (Macadamia integrifolia Maiden & Betche and Macadamia tetraphylla Johnson: Proteaceae) in South Africa

P.S. Schoeman1* & I.M. Millar2 1ARC-Tropical and Subtropical Crops, Private Bag X11208, Nelspruit, 1200 South Africa 2ARC-Plant Protection Research, Private Bag X134, Queenswood, Pretoria, 0121 South Africa

It is not clear when were first planted 30°59’37”E) on approximately 16 ha of mature in South Africa, but according to De Villiers (2003) macadamias. The method of introduction of this the Durban botanical garden already had a tree by species is currently unclear, but it is suspected that 1915. The first commercial seedlings were estab- it may have been accidentally imported with lished about 16 years later in the Nelspruit area, propagative material. The newly introduced but the industry only got underway during 1957 species joins three other introduced eriococcid when approximately 60 000 seedlings were sold by species (E. coccineus Cockerell, E. araucariae Maskell the Reims nursery in KwaZulu-Natal (De Villiers and E. leptospermi Maskell) and the only native 2003). species (Calycicoccus merwei Brain) (Gullan et.al. Since these humble beginnings, the industry has 2006). Specimens from the Barberton locality were grown significantly, and currently there are more submitted to the South African National Collec- than 23 000 ha under production in South Africa. tion of (ARC-Plant Protection Research, According to Giuricich (2016), it is expected that Pretoria), where their identity was confirmed as the 2018 crop will be in excess of 55 000 t. Eriococcus ironsidei by the second author (I.M.M.). Initially, pest and disease problems were negligi- Slide mounts of the specimens were deposited in ble. The polyphagous pest Pseudotheraptus wayi the National Collection under accession number Brown (Hemiptera: ) was only identified HC 7291 for permanent reference. on macadamias during 1977. The main pest of Ironside (1970) reported on the damage which macadamia, Bathycoelia distincta Distant (Hemi- this caused to macadamias in Queensland, ptera: Pentatomidae), was identified seven years Australia, and named it the ‘Macadamia felted later, but Bruwer (1992) already recorded 35 coccid’. Soon after this, it was described as a new kernel-feeding Hemiptera species in the Levubu species, Eriococcus ironsidei by Williams (1973) in area. By 2016 annual crop losses due to the his account of scale insects that occur on macada- Hemiptera pest complex ranged upwards of R400 mia. Miller & Gimpel (1996) transferred this million. This value is based on current crop species to the genus Acanthococcus Signoret, 1875. volumes and long-term average annual stink bug- They subsequently considered Acanthococcus to be induced crop losses of 10 % (Anon. 2015). a synonym of Eriococcus Targioni Tozzetti, 1868 Since the 1990s, large macadamia monocultures and the species returned to its original placement have been established in all major production in the latter genus (Miller & Gimpel 2000). How- regions. Most of the trees planted since then have ever, the status of Acanthococcus is currently not now matured, and because macadamia trees are resolved and certain authors (e.g. Kozár 2009; very large as well as dense, the orchards have Hodgson & Miller 2010) retain its validity. provided excellent sheltering sites for a plethora of Slide-mounted specimens of E. ironsidei can be new pests. Van den Berg et al. (2001) listed about 60 readily diagnosed as this species by comparison pests or potential pests from six insect orders on with the detailed illustration and morphological macadamia. account in the original description by Williams In April 2017 severe infestations of another new (1973). It is the only member of the scale insect insect pest, Eriococcus ironsidei Williams (Cocco- family Eriococcidae which is known so far to occur morpha: Eriococcidae), were observed in the on macadamia, and can thus be readily distin- Barberton valley in Mpumalanga (25°42’11”S guished from other Coccomorpha species that

*Author for correspondence. E-mail: [email protected]

Received 6 June 2017. Accepted 20 October 2017

ISSN 1021-3589 [Print]; 2224-8854 [Online] African Entomology 26(1): 247–249 (2018) DOI: https://doi.org/10.4001/003.026.0247 ©Entomological Society of Southern Africa 248 African Entomology Vol. 26, No. 1, 2018 feed on this crop host. Eriococcus ironsidei is host dispersal rates of this pest are very low and that specific, occurring only on species of Macadamia dispersal tends to occur primarily within infested (Miller & Gimpel 2000). trees. This is of particular interest for South African In the field, E. ironsidei can be recognised by growers as it indicates that this introduction could the ‘felted’ appearance of its protective sac or be relatively contained by quarantining the area scale cover. Certain armoured scale insect species and by treating affected trees diligently with (Diaspididae) that colonise macadamia may appropriate pesticides. appear superficially similar, but differ by having Macadamias are large trees and Drew (2003) smoother,hard scale covers with the exuviae of the mentioned that canopy volumes/ha often exceed first and second stages embedded in the adult 60 000 m3. This means that spray coverage in the female scale cover. The adult female scale of apical regions of trees is often inadequate. Fortu- E. ironsidei is dirty white or pale yellow, about nately, Wright & Conant (2009) found that in big 1.5 mm in length, with a raised circular opening at trees E. ironsidei prefers basal tree portions (tree the posterior end, while that of the male is white trunks, branches and foliage). Smaller trees on the and about 1.0 mm long (Williams 1973). Important other hand are often infested right to the upper- features of the adult female can be observed under most parts of the canopy. a stereo microscope by dislodging the scale cover According to Wright & Conant (2009), E. ironsidei from the bark or leaves of the plant with fine is a severe pest of macadamias in Hawaii but forceps and turning it over to expose the specimen occurs at low densities for long periods of time. beneath. The body is elongate-oval to rotund, 0.75 Sporadic outbreaks, however, have a devastating to 1.25 mm long, with a pair of pointed, conical impact on the trees and this pest is therefore elongate lobes at the end of the abdomen expected to have direct negative impacts on the (Williams 1973), and is orange in colour. Colour long-term profitability of the crop in South Africa. photographs of the various life stages are pro- Insecticidal oils have a low negative environmen- vided in Zarders & Wright (2016). tal impact and are very effective in controlling the The macadamia felted coccid is native to Austra- sessile adults. Unfortunately, this remedy will lia and is a significant quarantine pest threat have a lower impact on immature stages as severe which will affect trade and movement of propa- encrustations of adults often shield immature gative material between various producing coun- stages from the effect of pesticides. A follow up tries. Williams (1973) reported that it was inter- application a few weeks after the initial applica- cepted in 1954 on macadamia species imported tion may therefore be required. An appropriate into Hawaii. Fifty years later, this pest was found commercially available insect growth regulator to have become established there, when it was should also be effective against immature stages. observed for the first time in the Kona area of According to Wright & Conant (2009) parasitism in Hawaii (Conant et al. 2005). It had probably been Hawaii was relatively high at more than 80 % accidentally introduced shortly before then. Popu- mortality, suggesting that serious consideration lations of the coccid caused substantial damage to should be given to an integrated pest manage- well-established trees in the region. Damage ment programme, which may include the impor- included leaf malformation and die-back of large tation of parasitoids from Australia. The current portions of the trees. Ironside (1973) also men- pesticide-focused crop protection programme in tioned that dense infestations could cause flower South African macadamia orchards should, how- drop, leaf die-back and subsequent reductions in ever,be re-examined as a matter of utmost urgency nut set. as this practice will be detrimental for biological Wright & Conant (2009) observed that natural control of E. ironsidei.

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