The western corn rootworm Diabrotica vergifera vergifera LeConte (Coleoptera: Chrysomelidae) is an important pest on corn in Kansas. The larvae feed on roots and adults on the foliage and silks of corn. Bacillus thuringiensis (Berliner) is a naturally-occuring soilborne bacterium. It produces a proteinaceous parasporal crystalline inclusion which upon ingestion by insects, is solubilized in the midgut, releasing proteins called d-endotoxins which eventually lead to insect death. Bt corn plants were created by inserting selected exotic DNA from B. thuringiensis into the corn plant's own DNA.
This study was conducted to determine the effects of transgenic corn for corn rootworm control on nontarget soil mites (Prostigmata, Mesostigmata, Oribatids) and Collembola. Different Bt and non-Bt corn hybrids were planted in the field at eight locations in Kansas. Soil samples (5 cm x 5cm) were taken on three dates and were processed using Tullgren funnels. At all locations Prostigmata and /or Oribatids constituted the majority of the Acarina identified. With few exceptions there was no significant difference in their numbers between treatments at specific locations and specific dates. Collembola were present in moderate to low numbers at most locations and numbers of this group were more variable. In general there was no significant difference in numbers of Collembola between treatments. Based on our data, there seem to be no deleterious effects on soil microarthropods caused by the transgenic corn.
Species 1: Coleoptera Chrysomelidae Diabrotica virgifera virgifera (western corn rootworm)
Keywords: Transgenic corn, Nontarget microarthropods
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