Augmentative releases of the predatory earwig, Euborellia annulipes Lucas (Dermaptera: Labiduridae), for the management of the Asian corn borer, Ostrinia furnacalis (Guenee)

Issue Date

9-2006

Abstract

The effectiveness of the predatory earwig, Euborellia annulipes Lucas, in the management of the Asian corn borer (ACB), Ostrinia furnacalis (Guenee), the most destructive pest of corn in the Philippines, was evaluated in small- and large-scale field experiments. The use of earwigs as biocontrol agent to suppress ACB population on green corn (variety 'Lagkitan' and 'Asukar') and field corn (variety 'IPB-VAR-1') was subjected to different release regimens (3 times for green corn and 2 times for field corn, respectively, at the rate of 1 earwig/m2/release) and supplemented either with detasseling or microbial insecticide. The comparative treatments consisted of earwigs alone (T1), earwigs plus detasseling (T2), earwigs supplemented with microbial insecticide (T3), insecticide applications (farmers' practice) (T4) and an untreated control (T5). ACB damage was monitored 1 wk before and after earwig releases. The yield taken after harvest was converted to ton/ha. The calendared earwig releases (T1, T2 and T3) from the early whorl stage of the corn plant effectively controlled ACB infestation and prevented it from reaching the control action threshold (CAT) much later than the insecticide applications. Among the green corn treatments (small-scale field trials), earwig releases alone resulted in 45% higher yield than the untreated control. The increase in net income in the three corn varieties 'Asukar', 'Lagkitan' and 'IPB VAR-1' based on earwig releases alone (T1) was 21%, 18.45% and 78.55% more, over the farmers' practice of relying solely on insecticide application. For the field corn, all interventions increased the yield; however, the net income was low due to postharvest costs and low market price of shelled corn. Monitoring for the CAT after the last earwig releases and thereafter is recommended for determining the need and right timing of additional releases of the predatory earwigs or other interventions, especially in sweet corn varieties, which were verified to be more susceptible than the field corn variety.

Source or Periodical Title

Philippine Agricultural Scientist

ISSN

317454

Volume

89

Issue

3

Page

195-211

Document Type

Article

Language

English

Subject

Asian corn borer, Augmentative release, Control action threshold, Euborellia annulipes, Ostrinia furnacalis, Predatory earwig

Digital Copy

none

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