Natural parasitism of maize stemborers, Sesamia spp. (Lepidoptera: Noctuidae) eggs by Trichogramma evanescens (Hymenoptera: Trichogrammatidae) in Southeastern Turkey

Natural parasitism of the European corn borer eggs (Hübner) by Trichogramma spp. (Hymenoptera, Trichogrammatidae) was assessed in sweet corn field in north-west Serbia, region Vojvodina at the localities of Ruski Krstur, from 2004 till 2007. The rate of egg parasitism in 2004 varied from 35.89% to 73.58%. The parasitism in 2005 was lower than in 2004. On four different sampling dates in 2005 parasitism varied from 28.48% to 57.05% and averaged 39.4%. In 2006 parasitism fluctuated between 9.31 and 62.9%, averaging 32.15%. In 2007 parasitism varied from 36.8% to 54.54% and averaged 43.48%. The egg parasitoid species was identified as Trichogramma evanescens (Westwood). The study showed that this natural enemy occurred constantly in sweet corn fields but its number greatly fluctuated from year to year.

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Natural Parasitism and Release Efficiency of Trichogramma evanescens Westwood in Ostrinia nubilalis Hübner Attacking Maize in Turkey

Journal of Entomological Science ◽

10.18474/0749-8004-44.2.132 ◽

2009 ◽

Vol 44 (2) ◽

pp. 132-140 ◽

Cited By ~ 1

Author(s):

Sevcan Oztemiz

Keyword(s):

Ostrinia Nubilalis ◽

European Corn Borer ◽

Grain Weight ◽

Control Treatment ◽

Trichogramma Evanescens ◽

Insecticide Treatment ◽

Corn Borer ◽

Lepidoptera Pyralidae ◽

1000 Grain Weight ◽

Natural Parasitism

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.

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