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ARS Home » Research » Publications at this Location » Publication #72941
Title: DNA HYBRIDIZATION PROBE FOR ENDOPARASITISM BY MICROPLITIS CROCEIPES HYMENOPTERA: BRACONIDAE) (REVISE TITLE AND JOURNAL)

Author
item Greenstone, Matthew
item EDWARDS, MARTEN - UNIV OF ARIZONA

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/19/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: The cotton bollworm and tobacco budworm cause hundreds of millions of dollars in yield loss and costs of control annually in Southern cotton. The application of Integrated Pest Management methods to the control of these pests is hampered by a lack of simple tools for assessing the impact of naturally occurring parasitic insects. We describe a DNA fingerprinting gmethod for the most common species of parasitic micro-wasp which attacks these two pests. This method is able to detect the youngest immature stages of the wasp inside bodies of bollworm and budworm caterpillars, and is as accurate as older methods which are very tedious and require highly skilled personnel. It should be possible to perform the entire procedure in one day, making this prototype technology useful as a pest management tool. Properly used, this method could reduce the use of costly insecticide treatments by alerting growers to the presence of other, naturally occurring, forms of control.

Technical Abstract: We describe the first DNA hybridization assay for an insect endoparasitoid. The probe is a digoxigenin-labeled 438 base-pair fragment from a genomic library of the braconid Microplitis croceipes, a larval endoparasitoid of heliothine noctuids. The assay is run on nylon membranes and can detect 125 picograms of target DNA. Estimates of parasitization rate in large samples of simultaneously parasitized larvae of the host, Helicoverpa zea, made by hybridization probe assay of unamplified host homogenates and by dissection, are not statistically distinguishable for first or second instar parasitoid larvae. It should be possible to perform the entire procedure, from host collection and DNA extraction to evaluation of assay results, in one day, making this prototype technology useful as a pest management tool.