Researches Regarding the Attack Produced by Cur- culio glandium Marsh. in Production Unit II Badacin Belonging to the Şimleul Silvaniei Forestry Depart- ment * 1) 2) 1) 1 ) Ion OLTEAN , Nicolae FODORAN , Teodora FLORIAN , Mircea Ioan VARGA 1) , Romania. [email protected] Department of Environment2) and Plant Protection. University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Romania; Şimleul Silvaniei Forestry Department Print ISSN 1843-5254, Electronic ISSN 1843-5394 Bulletin UASVM Horticulture 71(1) / 2014 Abstract Curculio glandium Cydia (Laspiresia) amplana Curculio glandium Among the species of insects that attack acorns the most common are Marsh. (acorn weevil) and (rusty oak moth). The larvae of chew irregular galleries in the oak acorns, transforming the acorn cotyledons into a crumbly mass filled withCurculio black excrements.glandium Content acorns partially consumed by one larva, or are chewed entirely by two larvae. In theŞimleul period Silvaniei 2011-2012 forestry we proceededdepartment. to In monitor order to the evaluate frequency the frequencyof attack at of acorns, attack produced by the .Curculio The research glandium was conducted in 2011-2012 in production unit II Badacin, unit that belongs to Quercus petraea Quercus robur. acornIn weevil, , in three cantons (Măgura, Giurtelec and Cehei) was determined Curculiothree control glandium points.. Selected trees are: sessile oak and pedunculate oakCurculio glandium 2011 in the Măgura canton from the total acorns analyzed 304 were attacked by In Giurtelec canton in 2011 the frequencyby Curculio of acorns glandium attacked by was 52.4% and in Cehei canton the frequencyCurculio glandium of attacked acorns was 52.3%. In 2012, in Măgura canton 51.8% of the total acorn were attacked . In the canton of Giurtelec the frequency of attacked acorns by is 62.7% and in Cehei canton the frequency of attacked acorns is 51.2%. In all the cantons it was found an increase in frequency of attack Keywords: Curculio glandium acorn weevil, acorns, rusty oak moth, Quercus. from the basis of the slope to the top of the slope. , INTRODUCTION that the seedlings that proceed this regeneration In the oak stands increasingly is manifested have higher chances of growth and development a decline phenomenon. In general, forest decline (Holonec, 2007; Oltean and Stana, 2007). is determined by a complex of natural and In the natural regeneration of oak stands a anthropogenic factors that are interdependent. They great importance has the seed reserves existing in work with great aggressiveness in fragile forests the litter. After the seed fall to the ground, a part such as those from the boundary and outside natural of them is consumed by mammals, and those that vegetation areas and in stands strong ecological remain in the litter will germinate the following imbalances (pure stands, single stage,et al without year, whereas it needs a maturation period. The undergrowth, regenerated from shoots, grasslands, germination chances of the acorns decrease etwith al., polluted, etc.) (Holonec, 2004; Holonec ., 2008). the depth reaching the ground, and currently from Increasingly more foresters grant a great im por- the seedling survives less than 10% (Peason tance to the natural regeneration of forests, knowing 2002). Curculio glandium 67 Researches Regarding the Attack Produced by Marsh Among the biotic factors, the pest complex have precocious fallen. The degree of infestation has an important role in natural regeneration is assessed by the percentage of attacked acorns of forests. In this complex, the insects are best from all the fructification using the following scale: represented, followed by mites and nematodes poor infestation up to 10%,et middleal infestation and in the last period inclusive by nematodes. 10-25%,Curculio strong glandium infestation 25-50%, very strongCydia A particularity of pests that attacks the organs infestation over 50% (Roșca , 2011). of fructification is given by the lifestyle (hence present in the acorn, or different larvae of the damage modality) hidden, making their species can be distinguished easily, if they are not populations affected by fewer pests and natural Curculio we observe the excrements predators and the helpful entomophauna of this and emerge holes of adults from the acorn, so group is generally polyphagous pests. Cydia larvae has faeces like sawdust and the The most importantHymenoptera pests in this, group,Lepidoptera which, emerge hole is circular and larval excrement of Dipterain some and years Coleoptera can cause large economic losseset species are granulates and the emerge holes albelongs to the orders: is oval flat (György Csóka and Anikó Hirka, 2006). (Oltean, 2005; Holonec It should be noted that the number of emerging ., 2008). Curculionidae, holes from acorns is not a good indicator for the AmongCurculio the species glandium of insects that attack the acorns number of larvae inside (Anikó Hirka and György are the most common of the family Csóka, 2004) because were found situations especially (acorn weevil). This where from a single acorn through the emerging species attacks the acorn before release. hole came out 11 larvae (Csóka György and Anikóet al, This pest attacks acorns from the oak trees Hirka, 2006). found on the edge of forests or from isolated trees. According to some researchers (Branco The frequency and intensity of the attack are much 2002; Csóka György and Anikó Hirka, 2006) the higher in pure and rare stands. The adult is 5-9 mm infestation of acorns with acorns different species long, with a elongated oval body that varies from of carpophagous insects do not determine the lose dark brown to yellow gray to black. The rostrum of their germination ability. A large percentage of is long, thin and bent down and can reach half its acorns seems to keep the germination ability and body length in males and slightly longer in females. still MATERIALSbe able to produce AND viable METHODS seedlings. The larva is white, legless with a yellowish brown cephalic capsule full developed. The body is slightly Curculio glandium curved, robust with a strong tegument. The pest Monitoring of the attack frequency produced has usually one generation per year and winters by was carried out in the II as larvae in litter, in lodges made of granular soil Badacin production unit (UP), which has an area nymphs. In spring at an average daily temperature of 953.9 ha and is located in the area of the villages of 16-17 degrees Celsius the adults emerge from Badacin, Ilisua, Pericles, Lompirt, Giurtelecu the ground causing the maturation attack. For Şimleului, Cehei Sici and the city Şimleu Silvaniei. oviposition the females make deep holes in the From administrative point of view the production acorns and lay their eggs. The larvaeet will al chew unit is integrated into F.D. Zalãu, Şimleul-Silvaniei irregular galleries acorns transforming the acorn from the NationalCurculio Forest glandum “ROMSILVA”., in three cantons cotyledons into a crumbly mass (Roșca , 2011). To assess the frequency of attack produced by EspeltaQuercus et al, species with larger seeds are often acorn weevil attacked by weevils (Charnov, 1976 cited by (Măgura, Giurtelec and Cehei) were established 2009), these specieset al can be attacked three checkpoints. The checkpoints were installed at both by small and large species of acorn weevils the base of the slope, mid-of the slope and theQuercus slope (Mucunguzi, 1995; Espelta et al, 2009) and large petraeatop. For each control surfaceQuercus were roburselected. three seeds can feed the larvae before they reach the trees. The selected trees were sessile oak embryo (Mack, 1998; Espelta , 2009) and pedunculate oak The control of this pest is made in May- In the experimental trees was determined the June after the fly of the beetles that produce the horizontal projection of the crown on the ground. maturation attack (by shaking crowns on tilt) Under each tree were collected some fell acorns and in late summer and fall, after the acorns (harvesting was done uniformlyBulletin UASVM Horticultureover the 71(1) surface / 2014 68 et al OLTEAN projection). In the two years of observation, the In 2012 the Mãgura canton the surface acorn was harvested from control points between projection of the three trees from that were 20 to 30 September. harvested the acorns was 129.8 meters at the base The collected acorns were taken to the of the slope, 122.8 meters at middle of the slope laboratory, where we proceeded to sort the collected and 125.8 meters to the top of the slope. material on two categories: healthy acorns and Of the three2 monitoring points 953 acorns attacked acorns. All collected acorns were analyzed, were analyzed and were collected on average 2.4 in the sense that apparently healthy acorns were to 2.6 acorn/m average numbers of acorns per sectioned to detect all infestations. In the case of square meter crown projection was 39.2 units.Curculio attacked acorns the pest affecting it was determined. glandumWhen the seeds were analyzed was reported oligopodIn the caseslarvae where in the pests werepolypod still larvaein the that 494 acorns were attacked by acorn the identification was made by type of larvae , representing 51.8% of the total acorn ( weevil and analyzed, an increase of 11.4 percentage points in red caterpillar the acorn). In the acorns left by from year 2011 (Tab. 1). larvae, the identification was based on features of On all three points the attack frequency was leaving opening (circular hole in acorn weevil and 42.1% at the base of the slope (an increase of oval-oblongRESULTS hole AND in acorn DISCUSSIONS red caterpillar). 7.4% since 2011), of 49.3% in middle of the slope (increase of 10.4% than in 2011) and 63.6% at the top of the slope (increase of 16% since 2011). In 2011 the Măgura canton of three monitoring In the Giurtelec canton in 2011 of three points 752 acorns were analyzed and were collected monitoring points 763 acorns were analyzed (Tab.