Parasitoids and predators of pseudococcidae (hemiptera: coccoidea) in Ankara, Turkey

Natural enemies of mealybugs were surveyed in Ankara, Turkey, during the years 2001 to 2003. Twenty-three predatory species belonging to the insect orders Coleoptera (Coccinellidae, 17), Diptera (Chamaemyiidae, 3) and Neuroptera (Chrysopidae, 2; Hemerobiidae, 1); and 22 parasitoid species belonging to Hymenoptera (Aphelinidae, 2; Encyrtidae, 14; Platy-gasteridae, 1; Pteromalidae, 3; Signiphoridae, 2) were determined. The following ten species are newly recorded for the Turkish fauna:Sidis biguttatus Motchulsky,Nephus sinuatomaculatus Sahlberg (Coccinellidae),Leucopomyia alticeps Czerny,Parochthiphila (Euestelia) decipia Tanasijtshuk (Chamaemyiidae),Leptomastidae matritensis Mercet,Prochiloneurus bolivari Mercet,Rhopus sp.nr.acaetes (Walker),Stematosteres sp.,Eunotus acutus Kurdjumov, andChartocerus kurdjumovi (Nikol’skaya) (Chalcidoidea). http://www.phytoparasitica.org posting July 19, 2006.     

马尾松毛虫蛹、卵期寄生性天敌调查初报

通过对常山县松毛虫蛹、卵期寄生性天敌的调查，初步查得寄生蜂7科25种，寄生蝇2科7种，并分析子寄生性。     

四川省大邑县舞毒蛾天敌的研究*

１９９３年在大邑县共收集到舞毒蛾天敌３０种，其中寄生性昆虫１９种，捕食性昆虫９种，病毒和虫霉菌各１种。卵期平均寄生率为２７．０６％±０．５４％，大蛾卵跳小蜂是主要天敌。幼虫期天敌有病毒、斑痣悬茧蜂、毒蛾镶颚姬蜂和绒茧蜂等，平均杀死幼虫５１．５９％±６．４８％。蛹期主要天敌有寄蝇、广大腿小蜂和脊腿囊爪姬蜂等，平均寄生率达３２．９１％±２６．４０％。在舞毒蛾卵－蛹期，累计约有８７．６２％的个体被天敌致死。     

Effect of egg parasitoid density on the population suppression of Sunn Pest, Eurygaster integriceps (Hemiptera: Scutelleridae), and its resulting impact on bread wheat grain quality

The impact of the density of Sunn Pest egg parasitoids, Trissolcus grandis Thomson (Hymenoptera: Scelionidae), at three levels of Sunn Pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae), infestation was assessed on bread wheat variety Cham 6 in screened cages in the field for percentage of egg parasitism and grain quality. Percent parasitism ranged from 60.1 to 83.9%. No statistically significant differences were detected at parasitoid densities of 1, 2, or 3 insects per square meter at Sunn Pest densities of 2 or 4 insects per square meter. The quality of grain collected from all Sunn Pest infested cages without egg parasitoids was unacceptable for baking purposes and was significantly lower than grain from both non-infested plots and plots where either two or three egg parasitoids were present. The abundance of egg parasitoids in Al Hassakeh province in Syria was also determined. Egg parasitism was observed 1 week after the initiation of Sunn Pest oviposition and ranged between 22 and 59% in non-insecticide treated fields, while no parasitoids were recovered from insecticide treated areas within the same region. The impact of feeding by Sunn Pest on different wheat stages indicated that only feeding prior to the spike stage does not affect the bread-making quality of the grain.     

Temperature-dependent functional response of two aphid parasitoids, Aphidius colemani and Aphidius matricariae (Hymenoptera: Aphidiidae), on the cotton aphid

The functional response of two aphid parasitoids, Aphidius colemani Viereck and Aphidius matricariae (Haliday) (Hymenoptera: Aphidiidae), on the cotton aphid, Aphis gossypii Glover (Homoptera: Aphididae), was examined. Five constant temperatures (10, 15, 20, 25, and 30°C) and six host densities (2, 4, 8, 16, 32, and 64) were used during a 24-h period. At each temperature, 2–64 third-instar nymphs of A. gossypii were exposed to individual wasp mating pairs. A type II functional response model for both parasitoid wasps was fit separately for each temperature. The results showed that instantaneous attack rate (a) in A. colemani increased linearly as the temperature increases from 10 to 30°C, but in A. matricariae, (a) increased almost linearly with temperature to reach a maximum at 25°C, and then decreased at 30°C, displaying an asymmetrical dome-shaped pattern. The highest instantaneous attack rate for A. colemani and A. matricariae were calculated 0.940 ± 0.144 day⁻¹ at 30°C and 0.687 ± 0.157 day⁻¹ at 25°C, respectively. Handling time (T _h) for A. colemani was inversely proportional to temperature and ranged from 0.093 ± 0.026 day at 10°C to 0.032 ± 0.004 day at 30°C, but in A. matricariae, (T _h) was between 0.078 ± 0.015 day at 10°C and 0.036 ± 0.014 day at 20°C. A. colemani achieved higher parasitism rate than A. matricariae at higher temperatures. This observation suggests that A. colemani maybe more effective for biological control of the cotton aphid during warmer periods.     

Overwintering of the egg parasitoids Trichogramma brassicae and T. cacoeciae (Hymenoptera: Trichogrammatidae) in the Thrace region of Turkey

Classic biological control is generally understood as an environmentally safe practice of insect pest management. We investigated the overwintering abilities of Trichogramma brassicae Bezd. and T. cacoeciae Marchall in Tekirda Turkey. Parasitized eggs of Ephestia kuehniella Zell (Lep.: Pyralidae) by T. cacoeciae and T. cacoeciae were exposed under outdoor conditions between 17 August and 9 October. Emergence of T. brassicae and T. cacoeciae for the five exposure dates occurred in the same year. An emergence of 99% was observed in the following offspring for all of the tested parasitoid species exposed on 17 September. For eggs that were parasitized later than 9 November 2003, the emergence of parasitoids was in spring, on 19 March 2004. We found that T. brassica and T. cacoeciae were able to overwinter successfully on E. kuehniella. Fecundity of T. brassicae and T. cacoeciae females that overwintered on E. kuehniella was significantly different from the fecundity of control females that were reared under optimal conditions at 25°C. Our results demonstrate that the egg parasitoids T. brassicae and T. cacoeciae are able to overwinter successfully in Turkey .     

Parasitoid complex of<Emphasis Type="Italic">Cameraria ohridella</Emphasis> (lepidoptera: Gracillariidae) in Serbia

Fourteen species in two families of the order Hymenoptera: Ichneumonidae (1 sp.) and Eulophidae (13 spp.), were recorded during the study ofCameraria ohridella parasitoids at eight localities in Serbia. Among the observed parasitoids, the most significant species wereMinotetrastichus frontalis, Pediobius saulius, Pnigalio agraules andClosterocerus trifasciatus. In addition, at some localities the speciesMinotetrastichus platanellus andCirrospilus talitzkii were also significant. The parasitoids do not have a significant effect on the abundance ofC. ohridella because in the majority of study samples parasitism levels did not exceed 20%. http://www.phytoparasitica.org posting Feb. 23, 2004.     

Effect of milbemectin on the sweetpotato whitefly,Bemisia tabad

Milbemectin has a chemical structure close to the group of avermectins, which are derived fromStreptomyces avermitilis, and is considered primarily an efficient miticide. Effects of milbemectin on the sweetpotato whitefly,Bemisia tabaci Gennadius, were investigated under laboratory and field conditions. In bioassays conducted under controlled chamber conditions, the compound affected 1st instars ofB. tabaci, resulting in a LC₉₀ of 0.06 mg a.i. I-1. Later stage larvae were much less affected. Milbemectin is highly photodegradable in sunlight. In laboratory assays, when treated cotton seedlings were subjected to 3 h of sunlight before being exposed toB. tabaci adults, no mortality of the whiteflies was observed. Milbemectin at a concentration of 2 mg a.i. I-1 applied in combination with 0.2% ‘Ultra Fine’ mineral oil showed a residual activity of 67% adult mortality 10 days after application, whereas milbemectin alone had no appreciable activity. The effect of milbemectin on whitefly populations in a cotton field was compared with that of cypermethrin and of untreated control. Although milbemectin was not applied with mineral oil, it was more effective than cypermethrin in controlling the whitefly populations. This insecticide/miticide seems not to affect appreciably natural enemies ofB. tabaci. Milbemectin may be considered a compound with the potential for controllingB. tabaci populations. Mineral oils enhanced the potency of milbemectin on both whitefly larvae and adults. http://www.phytoparasitica.org posting July 27, 1999. Contribution No. 501/99 from the Inst. of Plant Protection, Agricultural Research Organization.     

广东美洲斑潜蝇寄生性天敌初步研究

本文对广东菜区美洲斑潜蝇Ｌｉｒｉｏｎｙｚａ ｓａｔｉｖａｅ寄生性天敌的种类及寄生情况进行了初步调查。结果表明,常见的美洲斑潜蝇寄生蜂有５种,其中以底比斯釉姬小蜂Ｃｈｒｙｓｏｃｈａｒｉｓ ｒｅｎｔｈｅｕｓ和冈崎釉姬小蜂Ｃｈｒｙｓｏｎｏｔｏｍｙｉａ ｏｋａｇａｋｉｉ为优势种。