Rice Water Weevil Females of Different Elytral Color Morphs: Comparisons of Locomotor Activity, Mating Success, and Reproductive Capacity

Abstract

Females and males of the rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Erirhinidae), have two elytral color morphs in Texas: the central pattern of their elytra is black (dark morph) or gray (light morph). In southeast Texas, the dark and light females exhibited similar proportions (28.6 and 32.0%, respectively) in populations collected during the spring. In this study, females of the two morphs were collected near rice fields in southeast Texas during April and May 2005. In the laboratory, light females were more active than dark ones. They mated equally successfully with males, irrespective of morph. For females supplied with males for 2 d or kept solitary, and then reared on rice seedlings for 48 d, no significant differences were found between the two morphs in oviposition period, number of eggs deposited, and survival rate. In both morphs, a proportion of mated females did not oviposit throughout the rearing period, implying that a mating experience might be necessary before reproductive development can be initiated. However, oviposition occurred in a proportion of females in which no mating experience could be detected, and their eggs produced larvae, which suggests the probability of existing parthenogenetic females in southeast Texas.