Diet affects male gonad maturation, female fecundity, and larval development in the granivorous ground beetleAnisodactylus punctatipennis

Abstract

1. Granivory is a specialised food habit in the Carabidae and is considered to have evolved from ancestral carnivory. Despite recent investigations, the mechanisms underlying this peculiar feeding shift have not been sufficiently elucidated. In particular, no studies have examined the effects of diet composition on male reproductive traits.2. This study examined male gonad maturation, female fecundity, and larval development under different diets (insect larvae, mixed seeds, and insect larvae + mixed seeds) for Anisodactylus punctatipennis (Coleoptera: Carabidae).3. Whereas sperm-bundle length, the durations of larval stages, and adult weight did not differ among diets, the weights of seminal substance-producing organs, fecundity, and larval survival were higher with diets containing seeds compared to the pureanimal diet. These findings provide the first conclusive evidence for granivory in Anisodactylus .4. This study is the first that demonstrates the effects of diet on male reproductive traits in a granivorous carabid. The results were consistent with similar observations for fecundity and larval performance in this and other studies. Thus, in addition to the female and larval traits, the dietary effects on male reproductive traits may also have played an important role in the evolution of granivory in the Carabidae.

Variable host phenology does not pose a barrier to invasive weevils in a northern hardwood forest

“…The ability to utilize a broad range of host plants is a common characteristic of many invasive invertebrates (Walter et al , 2010; Zhang et al , 2010). Dietary flexibility can provide a competitive advantage over conspecifics (Nylin & Gotthard, 1998) and be directly advantageous for the growth and development of eggs (Sasakawa, 2009), larvae (Unsicker et al , 2008; Morales Ramos et al , 2010; Trudeau et al , 2010) or adults (Marteleto et al , 2009).…”

Effects of diet on female fecundity and larval development in the carrion beetle Necrophila japonica

“…This result may indicate that in Silphinae, the diet shift from necrophagy to predatory habits occurs earlier in larvae than in adults. To test this hypothesis, future studies should investigate dietary effects on other life-history traits such as somatic maintenance (Fawki & Toft, 2005) and male reproductive traits (Sasakawa, 2009b). In addition, it is important to perform similar experiments in other species of Silphinae.…”

Full Issue

“…Instead, arthropod sequences were analyzed as present (or absent) within fecal samples and, for each prey item, its presence among all analyzed fecal samples is reported. All identified arthropod species found in more than one fecal sample were categorized by guild (predator, herbivore, detritivore, parasitoid, other) to further summarize the composition of adult and nestling fecal samples (Triplehorn and Johnson 2005, Sasakawa 2009, Marshall 2012, Evans 2014). The ''other'' guild includes species such as mosquitoes (Diptera: Culicidae) exhibiting intersex dietary differences.…”