Effectiveness of Trichogramma ostriniae and T. nubilale for controlling the European corn borer Ostrinia nubilalis in sweet corn

Abstract

Seven field releases of Trichogramma ostriniae and T. nubilale (Hymenoptera: Trichogrammatidae) were made separately and in combination in a sweet corn field to compare the level of parasitism in sentinel eggs of the European corn borer, Ostrinia nubilalis (Lepidoptera: Pyralidae). The results indicate that the levels of egg parasitism among different release dates differed mainly because of changes in weather and plant architecture within the season. The level of egg parasitism by releasing T. ostriniae alone was found to be 15% higher than that by releasing T. nubilale alone, and 20% higher than by releasing the combination of the two species. Further analyses using the logistic regression model for independent and correlated data indicated T. ostriniae to be more efficient at discovering host egg masses and to have higher levels of egg parasitism than T. nubilale. Mutual interference between T. ostriniae and T. nubilale was the main factor for the lower level of egg parasitism when T. ostriniae and T. nubilale were released together. The results suggest that T. ostriniae is the better candidate for augmentative releases for control of the European corn borer, and the two species should not be released into a corn field at the same time.

Field performance of entomopathogenic nematodes and an egg parasitoid for suppression of corn borers in Egypt

“…When the numbers of larvae were high on the control plots compared to release plots, it appeared that relative damage was considerably lower on the release plots. This corresponds with the findings of Wang et al (1999) and Wright et al (2002), who mentioned that ECB without releases of Trichogramma caused considerable losses to corn yield. The released plots achieved the highest yield Field performance of EPNs & Trichogramma to suppress corn borers 235 compared to the control plots as predicted by Bode and Calvin (1990).…”

Egg Parasitoids in Biological Control and Integrated Pest Management

“…Similarly, a combination of T. platneri and sterile insect release reduced fruit damage by codling moth in apples in field cages to a greater extent than either tactic used alone (Bloem et al 1998). An interesting field trial in which two different Trichogramma species, T. nubilale and T. ostriniae, were released either alone or in combination provided the surprising result that parasitism of European corn borer eggs was lower for the combined release than for either of the two species alone (Wang et al 1999). In contrast, a combination of egg and larval parasitoids was more successful for control of sugarcane borer in Brazil (Parra and Zucchi 2004).…”

Host-Foraging Success of Three Species of Trichogramma (Hymenoptera: Trichogrammatidae) in a Simulated Retail Environment

“…Furthermore, T. pretiosum has been collected from wild stored product moth populations in peanut warehouses (Brower 1984). T. ostriniae has been extensively explored as an augmentative biological control agent for O. nubilalis in field and sweet corn (Wang et al, 1997(Wang et al, , 1999Hoffman et al 2002;Wright et al 2002), was shown capable of parasitizing the eggs of P. interpunctella in bulk wheat (Jeffery Gardener, personal communication), and has a history of being reared on a similar stored product pyralid Ephestia kuhniella (Smith 1996). Likewise all three Trichogramma strains used in this study had been reared on E. kuhniella for more than 100 generations (Synthia Penn, personal communication; Jeffery Gardener, personal communication).…”