Journal of Pest Science (2019) 92, 443-451

Katarina M. Mikac, Darija Lemic, Hugo A. Benítez and Renata Bazok (2019)
Changes in corn rootworm wing morphology are related to resistance development
Journal of Pest Science 92 (2), 443-451
Abstract: The western corn rootworm, Diabrotica virgifera virgifera LeConte, is the most serious pest of maize across the US Corn Belt and now Europe. The beetle has repeatedly demonstrated its ability to adapt to pest management strategies through evolution of resistance to conventional insecticides, the cultural practice of crop rotation and now to the Bacillus thuringiensis (Bt) toxin which is produced by genetically modified maize. In this study, the wing morphology of 358 western corn rootworm adults from Iowa, Indiana and Illinois, USA, was investigated using geometric morphometric procedures. The populations investigated comprised resistant (i.e. soybean–maize rotation and Bt-maize variants) and non-resistant beetle populations. Data analysis was divided into two groups: (1) resistant versus non-resistant and (2) rotation-resistant versus Bt-maize rootworm populations. Results showed that morphological differences exist in the hind-wing shape of both rotation and Bt-maize-resistant versus non-resistant populations and rotation-resistant versus Bt-maize-resistant variants. Across all three types of rootworm variants investigated, the movement of landmarks 8, 9 and 14 drove the wing shape differences found. These landmarks relate to the basal radial vein and are a key anatomical character used to distinguish different wing morphotypes in rootworm. This study demonstrates the utility of hind-wing morphology/shape as an inexpensive and accessible population biomarker for rootworm. With simple equipment (camera mounted microscopes or flatbed scanners) and readily available free software to capture and analyse landmark (shape and size) data, it is possible to effectively monitor pest resistance development and associated field-based population-level differences. The biological implications of the differences in wing shape found and how this relates to rootworm flight and consequently its dispersal and invasion capabilities are also explored.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Katarina M. Mikac, Darija Lemic, Renata Bazok

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Diabrotica virgifera	Maize/corn (Zea mays)	U.S.A. (mid N)
	Diabrotica virgifera	Maize/corn (Zea mays)	U.S.A. (NE)
Bacillus thuringiensis genes in crops (entomopathogen)	Diabrotica virgifera		U.S.A. (mid N)
Bacillus thuringiensis genes in crops (entomopathogen)	Diabrotica virgifera		U.S.A. (NE)