SEXUAL SELECTION IN THE SPOTTED CUCUMBER BEETLE, DIABROTICA UNDECIMPUNCTATA HOWARDI (COLEOPTERA: CHRYSOMELIDAE): MALE TRAITS FAVORED BY CRYPTIC FEMALE CHOICE.

Open Access
Author:
Darlington, Mark Burton
Graduate Program:
Biology
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
December 08, 2006
Committee Members:
  • James Harold Marden, Committee Chair
  • Andrew George Stephenson, Committee Member
  • Shelby Jay Fleischer, Committee Member
  • Mark C Mescher, Committee Member
  • Douglas Cavener, Committee Member
Keywords:
  • sexual selection
  • cryptic female choice
  • mating display rate
Abstract:
Abstract In the spotted cucumber beetle Diabrotica undecimpunctata howardi (Coleoptera: Chrysomelidae), the female determines the final outcome of mating; internal muscle control allows her the capability of blocking the transfer of sperm from the male. Males respond to this “cryptic female choice” by rhythmically stroking the female with their antennae in a distinctive pattern. The rate of this “antennation” is the best known predictor of a successful outcome for the mating, males that have a higher antennation rate are more likely to pass a spermatophore to the female. I examined a number of male traits testing for correlations with antennal stroking behavior, and found two significant results: (1) Antennation rates increased with higher levels of inbreeding, the opposite of expectation, and (2) males with fast antennal stroking rates had a greater propensity to fly rather than run in a simulated escape test. Subsequent fieldwork indicated a high proportion of the beetles that appeared in squash fields early in the season were “flyers”.