Role Of Predators In Suppression Of The European Corn Borer Ostrinia Nubilalis Hubner On Sweet Corn

Author : Matthew Wayne Bickerton
Publisher :
ISBN 13 :
Total Pages : 90 pages
Book Rating : 4.:/5 (773 download)

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Download or read book Intercropping for Conservation Biological Control of European Corn Borer Ostrinia Nubilalis Hübner (lepidoptera: Crambidae) in Bell Peppers written by Matthew Wayne Bickerton and published by . This book was released on 2011 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: The European corn borer, Ostrinia nubilalis Hübner, is the most important insect pest of sweet peppers in New Jersey. Management of this pest has been dependent on insecticides. Numerous predators feed on the eggs and larvae of O. nubilalis and under certain conditions they can contribute high levels of biological control. Maximum control by these predators can be achieved by using selective insecticides and providing nutritional resources when prey is scarce. From 2008 to 2010, we tested the effects of bell peppers intercropped with flowering plants: dill, Anethum graveolens L.; coriander, Coriandrum sativum L.; and buckwheat, Fagopyrum escuelentum Moench on improving O. nubilalis egg predation and reducing its damage to the fruit. By placing O. nubilalis egg masses on sentinel plants, we found that the major predators in New Jersey were the coccinellid Coleomegilla maculata DeGeer, the anthocorid Orius insidiosus Say, and chrysopid larvae, Chrysoperla sp. Egg predation was negatively affected by aphid populations. Aphid populations were reduced and egg predation was enhanced in plots intercropped with flowering plants. Insecticide sprays were used to determine the compatability of a selective material, spinosad, on O. nubilalis suppression in both intercropped and non-intercropped systems. Unsprayed fruit damage was greater in non-intercropped plots with high O. nubilalis densities than intercropped plots, but not in spinosad-treated fruit. Thus spinosad may not be compatible with intercropping systems due to its toxicity to certain predators. In order to test for affects of floral provisioning on biological control, gut contents of O. insidiosus were screened for DNA from the flowers, O. nubilalis, and M. persicae. It was found that the dispersal of this predator from the flowers into the pepper crop was greatest when flowers began to senesce. However, O. nubilalis was not detected in the guts of O. insidiosus during late-June through mid-August sampling periods. Myzus persicae DNA was detcted, indicating that aphids were the primary food during and after peak aphid densities. The proportion of predators feeding on aphids was similar for intercropped and non-intercropped plots, indicating that aphids were a preferred host and that flowers did not distract O. insidiosus from feeding on aphids.