Comportamento de corte e cópula e papel do tamanho e simetria na seleção sexual de Dysdercus maurus Distant, 1901 (Hemiptera: Pirrhococoridae)

Abstract

This study investigated the hole of size and corporal symmetry in the sexual selection of D. maurus, an insect-plague responsible for serious economic injuries in cotton cultures. Aspects of the courtship and mating behavior of this species were also described. In order to obtain the morphometric measurements, 30 single males and 30 couples were used for slide confection. For corporal biomass assessment, 40 single males and 90 couples were weighted. Moreover, 50 single females and 50 single males were used for the observation of the courtship and mating behavior. The morphometric measurements achieved were simplified by the Principal Component Analysis in order to attain a multivaried index of size. The corporal asymmetry was estimated by calculating an index of Fluctuating Asymmetry (FA). The morphometric measurements, the weight and the indexes of size and FA were compared between paired and single males by using the t test. The relationship between male and female sizes was verified by using the simple linear regression. In all mating attempts male-female struggles were observed and the courtship was always performed by males. The t test indicated significant differences in the individuals weight, in the length of the 1° fore tarsus and in the FA index of the hind tibia between paired and single males. There is a relationship between the couple s weights. Thus, females of D. maurus choose indirectly the male based on morphometric and behavioral characteristics that allow the males to be good manipulators. Larger males with more symmetrical hind tibias and longer fore tarsus are more successful in sexual selection.