Inheritance of Host-Plant Choice in the Seed Beetle Callosobruchus maculatus (Coleoptera: Bruchidae)

Evolutionary genetics of lifespan and mortality rates in two populations of the seed beetle, Callosobruchus maculatus

“…The South India (SI) population was collected in 1979 from infested pods of mung bean and the closely related black gram (both V. radiata) in Tirunelveli, India (Messina and Slade, 1997). The Burkina Faso (BF) population was collected in 1989 from infested pods of cowpea (V. unguiculata) in Ouagadougou, Burkina Faso (Messina, 1993;Messina and Slade, 1997). These two populations differ in a whole suite of traits, including body size, lifetime fecundity, patterns of egg dispersion, oviposition preference, and adult longevity (see Introduction).…”

“…The SI and BF populations of C. maculatus differ substantially in adult size (SI are larger), adult longevity (SI live longer), larval competitiveness (SI are contest competitors, BF are scramble competitors), egg size, oviposition preference (SI prefer to oviposit on mung seeds, BF prefer cowpea), egg dispersion (SI disperse eggs more uniformly) and degree of paternal investment (greater male investment into reproduction in BF males) (Messina and Slade, 1997;Savalli et al, 2000). Some of these life history differences are directly attributable to seed size differences between mung and cowpea, which selects for differences in female egg-laying strategies, larval competitive ability, and body size.…”

“…For example, C. maculatus is a seed parasite. Host seed size variation between these two populations has driven differentiation in body size and larval aggressiveness; selection favors large beetles that are highly aggressive when larvae develop inside of Vigna radiata seeds, because the seeds are small and can only support the development of one or two larvae, but favors the evolution of less-aggressive larvae that are small and tolerant of scramble competition when larvae develop inside of the larger V. unguiculata (Messina, 1991;Messina and Slade, 1997). Relevant to this study is the observation that the large differences in body size between populations correspond to large differences in adult lifespan between populations (Figure 1), suggesting that host-associated selection on larval aggressiveness and body size may have driven large differences in other life history traits, including adult lifespan.…”

Genetic architecture underlying convergent evolution of egg-laying behavior in a seed-feeding beetle

“…Each unmated female was collected within 24 h of adult emergence, and was paired with a random non-sibling male from the same cross type. This design does not allow us to disentangle male from female effects on oviposition behavior, but we had no a priori reason to expect a significant effect of the source of the male (Messina 1989;Messina and Slade 1997). Females were allowed to oviposit for *24 h. Each female's distribution of eggs was scored using the uniformity index (U) of Messina and Mitchell (1989).…”

Inheritance of an oviposition behavior by an egg parasitoid

“…Thus, genetic variance in oviposition preference may be an initial requirement for the evolution of host specialization. A few studies of oviposition preference variation within phytophagous insect populations show variation in the genetic basis for this trait (reviewed in Jaenike and Holt, 1991;Tucié et al, 1997;Bossart and Scriber, 1999), and hybridization studies of different populations show wide variation in the number of loci affecting this trait, the relative contributions of dominance, additivity, and epistasis, and the roles of sexlinked versus autosomal genes (reviewed in Messina and Slade, 1997;Janz, 1998). The variable findings make generalizations difficult, although heritable variance, in the broad and narrow sense, has been uncovered in most of the species studied.…”