International audienceA molecular key for the identification of common Trichogramma (Hymenoptera: Trichogrammatidae) species found in agricultural settings around the Mediterranean is developed based on the sequence of the internal transcribed spacer 2 of the ribosomal cistron. Using the size of the ITS2 PCR product and restriction fragment length polymorphisms of the amplicon, ten Trichogramma species (T. bourarachae Pintureau and Babault, T. brassicae Bezdenko, T. cacoeciae Marchal/T. embryophagum Hartig, T. cordubensis Vargas and Cabello, T. dendrolimi Matsumura, T. euproctidis Girault, T. evanescens Westwood, T. nerudai Pintureau and Gerding, T. oleae Voegelé and Pointel, and T. pintoi Voegelé) can be distinguished
Essential oil vapors obtained by the hydrodistillation of Prangos ferulacea (Umbelliferae) were tested on the different stages of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) and egg parasitoid Trichogramma embryophagum Hartig (Hymenoptera: Trichogrammatidae). Extracts of the volatile fractions from P. ferulacea were analyzed by capillary gas chromatography-mass spectrometry. The major compound of the essential oil was detected as 2,3,6-trimethyl benzaldehyde (66.59%) and the minor compound was heneicosane (0.02%). The third instar larvae of E. kuehniella (LC 50 : 379.662 µL L -1 air and LC 99 : 538.755 µL L -1 air) and the pupal stage of T. embryophagum (LC 50 : 5.947 µL L -1 air and LC 99 : 19.568 µL L -1 air) were found to be the most tolerant stages. The essential oil was toxic to the adult stages of both the pest and its parasitoid with 100% mortality obtained after 24 h at 1.0 and 0.25 µL L -1 air, respectively. The LC 50 and LC 99 values of the essential oil against the egg stages of E. kuehniella and T. embryophagum were 320.372-486.839 µL L -1 air and 2.121-5.662 µL L -1 air, respectively. In general, the mortality rate increased with the increasing concentration of essential oil. The results of the study indicated that essential oil of P. ferulacea should be used as a control agent against E. kuehniella for an integrated pest management program.
Two egg parasitoid wasps, Trichogramma euproctidis (Girault) and Trichogramma brassicae (Bezdenko) (Hymenoptera: Trichogrammatidae) were identified in the study. The taxonomy of these wasps is problematic because of their small size and lack of distinguishable morphological characters. The DNA sequence variation from the internal transcribed spacer 2 (ITS2) region of nuclear ribosomal DNA (rDNA) was analyzed from these two Trichogramma species. This technique provides quick, simple and reliable molecular identification of Trichogramma species
This study was carried out to determine the efficacy of different applications of a biopesticide for reduction of aflatoxin contamination in peanut. The biopesticide, afla-guard, delivers a nontoxigenic Aspergillus flavus to the field where it competes with naturally occurring toxigenic fungus. Biocontrol treatments included: (ı) soil application during sowing, (ıı) multiple application during sowing and 40 days after planting, (ııı) foliar application at 60 days after planting (ıv) control (untreated plots). Biopesiticide was applied to peanut plots in 2015 and 2016 in Randomized Complete Block Design with four replications. Peanuts were collected from control and treated plots at harvest-drying-pre-storage periods and analysed for aflatoxins. Aflatoxin concentrations were generally quite low in 2015, also the aflatoxin concentration in treated samples (from 0.04 to 0.71 µg/kg) was reduced by 97.38 to 99.82% compared with controls (from 21.84 to 27.12 µg/kg). In 2016, reductions were also noted for all biocontrol treatments (from 89.07 to 92.39%) compared with controls. In conjunction with the reductions in aflatoxin contamination, biocontrol treatments produced significant reductions with biopesticide in peanut. Therefore, it can be said that a biological control method is a promising approach for controlling aflatoxin.
The natural parasitism rate and the release efficiency of the egg parasitoid, Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae), in the biological control of the European corn borer, Ostrinia nubilalis Hübner (Lepidoptera: Pyralidae), was determined in field plots of maize in the Eastern Mediterranean, Turkey. Parasitoids were released in maize plots as parasitized eggs of laboratory-reared Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). The parasitized eggs (n = 150,000) were released twice in a 10-d interval at the beginning of the oviposition period of the third generation of O. nubilalis in the second crop of maize in released treatment (without insecticides). Other treatments were an untreated control (without wasps and without insecticides) and an insecticide treatment (Lambda-Cyhalothrin, 50 g I−1 300 ml ha−1; without wasps). Ostrinia nubilalis egg masses, larvae and plant damage were regularly assessed until crop harvest. Parasitization of egg masses by T. evanescens was determined in each sample. The mean (± SD) percentage of parasitized O. nubilalis eggs was 86.2 ±l11.6 (± SD)%. Compared with the control treatment, the number of plants damaged by European corn borer larvae in the release treatment was reduced by 96%, whereas the number of larvae was reduced by 95.2%. Average grain yield was 8,800 ± 15.2 kg ha−1 (380.0 ± 1.6 g per 1000 grain weight) in the Trichogramma release treatment without insecticide, 7,000 ± 28.8 kg ha−1 (314.8 ± 2.9 g per 1000 grain weight) in the control treatment, and 8,533 ± 8.8 kg ha−1 (360.4 ± 8.5 g per 1000 grain weight) in the insecticide treatment. The grain yield and 1000 grain weight differences differed significantly (P ≤ 0.01) between the untreated control and the other two treatments (released treatment and insecticide treatment). Natural parasitization of O. nubilalis eggs by T. evanescens as observed in control and insecticide-treated plots was 30.2%. These results indicate that biological control of O. nubilalis with T. evanescens should be developed as an integral control method in integrated management programs for maize grown in Turkey.
Alatoxin (AF) and cyclopiazonic acid (CPA) contaminations are very important problems for peanuts and its products. The aim of the study was to detect alatoxin (types B and G) and cyclopiazonic acid (CPA) occurrence and critical periods of toxin production in peanuts collected from diferent research areas of Osmaniye and Adana, Turkey, in 2015. Peanut kernels toxin analysis was performed in four diferent periods during the harvest, drying, prestorage, and storage. Total alatoxin occurrence in peanut kernels was analyzed by immunoainity chromatography-reversed-phase high-performance liquid chromatography (IAC-HPLC) analysis and cyclopiazonic acid occurrence in peanut kernels was analyzed by thin layer chromatography (TLC). Alatoxin levels in 76 out of 102 contaminated samples were from 0.3 to 1333.42 μg/kg. Cyclopiazonic acid levels in 18 out of 102 peanut samples were from 16.6 to 44.44 μg/kg. An unusual patern of mycotoxin production (alatoxin types B and G simultaneously with CPA) was seen in 11 of 102 peanuts samples. Six of nine samples were from the storage period. Alatoxin contamination during harvesting (64%) and drying (75%) were higher than prestorage (53%). Alatoxin (93%) and cyclopiazonic acid (30%) were the most produced during storage. The results showed that storage period was signiicantly important for the presence of two mycotoxins according to the statistical analysis.
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