Male lifetime mating success in relation to body size in Diabrotica barberi

Authors: French, Bryan; HAMMACK, LESLIE - Retired ARS Employee

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/21/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Body size is often an important component of male lifetime mating success in insects, especially when males are capable of mating several times over their lifespan. We paired either a large or small male northern corn rootworm with a female of random size and noted copulation success. We observed courtship and copulation durations and offered each male a virgin female up to three times a week. Of 87 males (38 large, 49 small), 72 (83%) mated successfully when first offered a female, 36 for both the large (95%) and small (73%) males, resulting in the small males showing a higher frequency of female rejections. No difference in longevity occurred between the large (69 d) and small (74 d) males. There were 1346 mating opportunities for the large (644) and small (702) males, with a mean of 19 females per male. The small males showed a higher percentage (35%) of unsuccessful pairings compared with the large males (20%). For both the large and small males, the probability of successful copulation decreased as the males aged. For the successful pairings, the courtship duration did not vary with male size, but the small males copulated for longer periods than the large males, with the copulation duration longest for small males mating large females and shortest for large males mating small females. Resistant males could have a reproductive disadvantage or advantage over susceptible males depending on whether resistance to Bt corn were to reduce or enhance male size, respectively.