Flight and crawling activities of Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae) in relation to morphometric traits

Abstract

Morphometric traits and body weight are often used to study changes in fitness. For the invasive alien maize pest, Diabrotica virgifera virgifera LeConte, little information is available regarding the possible relationship between morphometric traits and adult activity, which reflects the ability to disperse and invade. Flight and crawling activities of D. v. virgifera adults were investigated in relation to six different morphometric traits as well as body weight, sex and age. This laboratory study revealed that flight activity of D. v. virgifera differed between sexes and changed with age. Young adults of both sexes flew more frequently and took off faster than mature adults. Males flew more frequently and took off faster than females, regardless of age‐class. No such differences were found for crawling frequency, but young males crawled faster than young females. Further analysis revealed that fresh body weight and morphometric traits of young adults were better predictors of flight and crawling activity than the same measurements made on mature adults. Particularly pronotum and elytra measurements on young adults are recommended for bioassay studies on activity parameters of D. v. virgifera.

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

“…Although dispersal was not directly investigated in this study, we have provided morphological results (i.e., larger hind wings in females versus males) similar to that of Li et al (2009) andLi et al (2010) that are supportive of increased female D. v. virgifera longdistance dispersal capabilities, based on longer and broader elytra and now hind wings compared with males. We hypothesize that the observed sexual dimorphism in wing shape may be related to the sexspeciÞc dispersal behavior of D. v. virgifera and that newly mated females play a key role in the dispersal process and are likely to promote population establishment, as they likely form the leading edge of the invasion front.…”

“…They showed that elytra width and length were inßuenced by sex and that elytron width and length were signiÞcantly broader in females than in males, regardless of age. Li et al (2010) found that ßight activity was greatest in young adults, especially preovipositional but mated females, with females having signiÞcantly longer and broader elytra and implicated in the continued range expansion of this pest in Europe and the United States. Previously, Mabry et al (2004) found a similar result and showed that female elytra length was greater in rotation-resistant than susceptible individuals.…”

“…Previously, Mabry et al (2004) found a similar result and showed that female elytra length was greater in rotation-resistant than susceptible individuals. Li et al (2009Li et al ( , 2010 urge others to further explore the use of these phenotypic characters to better understand the dispersal capabilities and patterns of this pest, especially in light of its propensity for resistance.…”

“…Most morphometric work on Diabrotica species has used larval head capsule width to document aspects of their biology (Sweetman 1925(Sweetman , 1926Pitre and Kantack 1962;George and Hintz 1966;Branson and Ortman 1970;Clark and Hibbard 2004;Oyediran et al 2004), as a species diagnostic tool (Hammack et al 2003), and to document the effect of maize irrigation on this character (Agosti et al 2009). Li et al (2009Li et al ( , 2010 recognized a need to understand the relationship between D. v. virgifera morphometric traits and its dispersal and invasiveness. They showed that elytra width and length were inßuenced by sex and that elytron width and length were signiÞcantly broader in females than in males, regardless of age.…”

Phenotypic trait changes in laboratory – reared colonies of the maize herbivore,Diabrotica virgifera virgifera

“…Sixteen phenotypic traits were assessed according to Li et al (2009Li et al ( , 2010: five fitness traits (fecundity, overwintering egg survival, larva-to-adult survival, egg-to-adult survival, and adult lifespan), four activity traits (proportion of adults crawling, crawling speed, proportion of adults flying, and flight take-off response), and seven morphometric traits of adults (fresh body weight, elytra length and width, pronotum length and width, head capsule width, and hind tibia length). Assessments were conducted with D. v. virgifera from two rearing series (= repetitions) of each colony (Begley, 2013).…”