Wing Shape and Size of the Western Corn Rootworm (Coleoptera: Chrysomelidae) is Related to Sex and Resistance to Soybean-Maize Crop Rotation

Abstract

The western corn rootworm, Diabrotica virgifera virgifera LeConte, is a major pest of maize in the United States and more recently, Europe. Understanding the dispersal dynamics of this species will provide crucial information for its management. This study used geometric morphometric analysis of hind wing venation based on 13 landmarks in 223 specimens from nine locations in Illinois, Nebraska, Iowa, and Missouri, to assess whether wing shape and size differed between rotated and continuously grown maize where crop rotation-resistant and susceptible individuals are found, respectively. Before assessing differences between rotation-resistant and susceptible individuals, sexual dimorphism was investigated. No significant difference in wing (centroid) size was found between males and females; however, females had significantly different shaped (more elongated) wings compared with males. Wing shape and (centroid) size were significantly larger among individuals from rotated maize where crop-rotation resistance was reported; however, cross-validation of these results revealed that collection site resistance status was an only better than average predictor of shape in males and females. This study provides preliminary evidence of wing shape and size differences in D. v. virgifera from rotated versus continuous maize. Further study is needed to confirm whether wing shape and size can be used to track the movement of rotation-resistant individuals and populations as a means to better inform management strategies.

Effect of fruit host on wing morphology in Drosophila suzukii (Diptera: Drosophilidae): A first view using geometric morphometrics

“…Previous studies of differences in insect shape showed that GM can be used in pest population studies (Mikac et al 2013;Benítez et al 2014aBenítez et al , 2014bLemic et al 2014). Previous studies of differences in insect shape showed that GM can be used in pest population studies (Mikac et al 2013;Benítez et al 2014aBenítez et al , 2014bLemic et al 2014).…”

Evolutionary directional asymmetry and shape variation inDiabrotica virgifera virgifera(Coleoptera: Chrysomelidae): an example using hind wings

“…Then, an asymmetric component was computed from the differences between the original and reflected copies Klingenberg, Barluenga & Meyer, 2002). A general discussion of how Procrustes distances are used in geometric morphometrics is provided by Mikac et al (2013). To assess the significance of DA relative to ME, the left and right wings of 30 individual beetles were digitized twice .…”

“…approximately 1996) to the present time (2011) have revealed minimal genetic differences between populations and among regions (Lemic et al, 2013). Mikac, Douglas & Spencer (2013) recently used wing shape and size as a population marker to demonstrate that differences in hind wing shape were detectable among D. v. virgifera sampled from maize-soybean rotation resistant and susceptible populations in the USA. Indeed, Bouyer et al (2007) was able to demonstrate this for the tsetse fly Glossina palpalis gambiensis Vanderplank, when comparing wing shape and size differences with population genetic differences along an ecological cline, where geometric morphometrics analysis of wing shape and size demonstrated clinal differences, a result that was not mirrored by the microsatellite markers used.…”

“…Bouyer et al (2007) suggested that the influence of environment on the genotype of an organism takes much longer to manifest than on the phenotype of an organism and, as such, the study of environmental influences on populations and individuals should be made on phenotypic, rather than genotypic, characters. Mikac et al (2013) recommended the use of geometric morphometrics as a tool to understand how hind wing shape and size have changed during the invasion of maize-growing areas in the USA and Europe. Mikac, Douglas & Spencer (2013) recently used wing shape and size as a population marker to demonstrate that differences in hind wing shape were detectable among D. v. virgifera sampled from maize-soybean rotation resistant and susceptible populations in the USA.…”

Monitoring techniques of the western corn rootworm are the precursor to effective IPM strategies

“…shape analysis) renders the quantification of wing morphology (size and shape) a readily accessible tool for investigating population or geographic differences and for possibly inferring dispersal ability . Geometric morphometric is useful in quantifying the morphological variation within and among species, and geometric morphometric methods begin with the collection of two‐ or three‐dimensional coordinates of biologically definable landmarks, such as hind wing vein intersections in WCR . However, morphometric data are yet to be used to assist in the monitoring of existing or new populations or to inform or evaluate management practices by country or region.…”