Somatic condition determines female mating frequency in a field population of the grasshopper Eyprepocnemis plorans

Abstract

Mating pairs and nonmating individuals of the grasshopper Eyprepocnemis plorans were collected in a natural population during the 1992 season, in order to determine whether sexual preferences of males and females are correlated with various morphological and physiological characters. These included condition based on body size and somatic and gonadal weight. A comparison of frequency distributions for these characters between the two types of individuals showed that mating frequency (the probability of being sampled while mating) was independent of the characters measured in males but was highly significantly dependent on somatic condition in females. Mating females showed a better somatic condition (defined as the residuals of the regression of somatic weight on body size) than nonmating ones. The implications of this finding in shaping the polygynandrous mating system of this species are discussed.

Chromosomal polymorphism, morphological traits and male mating success in Leptysma argentina (Orthoptera)

“…Male sexual selection may be exerted at the level of male mating success or as selection acting through sperm competition (Martín‐Alganza et al ., 1997). The present paper aims to detect possible effects of chromosome and morphometric variables on male mating success in the grasshopper Leptysma argentina by using univariate and multivariate approaches The results are discussed in the light of the previous knowledge of natural selection acting on other fitness components in this species.…”

Effects of B chromosomes and supernumerary segments on morphometric traits and adult fitness components in the grasshopper, Dichroplus elongatus (Acrididae)

“…Female sexual selection was associated with male reproductive investment. For example, there is compelling evidence showing the importance of feeding courtship through spermatophores in Orthoptera (Gwynne, 1981; Martín‐Alganza et al. , 1997) and yeast gifts in Drosophila buzzatii (Norry & Vilardi, 1996).…”

The evolution of sexual size dimorphism: the interplay between natural and sexual selection

“…In the grasshopper Leptysma argentina, sexual selection was stronger on male femur length than on female femur length, but selection on thorax length was stronger in females than in males (Colombo et al 2004). In the grasshopper Eyprepocnemis plorans, somatic condition (body size and somatic mass) and reproductive condition (gonad mass) were positively correlated to female, but not to male, mating success (Martín-Alganza et al 1997). In S. purpurascens the magnitude of selection on body size was similar in both sexes , 2002.…”