Specialisation in prey capture drives coexistence among sympatric spider‐hunting wasps

Abstract

1. Sister taxa that coexist in the same space and time often face competition due to the use of similar resources. However, some closely related species can adopt fine-grained specialisation in resource use to coexist. This study investigated niche overlap between three sympatric spider-hunting wasp species of the genus Trypoxylon (Hymenoptera: Crabronidae) known to nest in three of the habitats found in the study area.2. First, the co-occurrence of these wasp species in the three habitats was estimated, as a proxy for potential competition. Then, the following hypotheses were tested: (i) niche partitioning is seen more often between species that co-occur in a habitat, whereas there is niche overlap between species nesting in distinct habitats (prey specialisation hypothesis); and (ii) wasp species capture prey according to their size (physical constraint hypothesis).3. Two pairs of wasp species were found consistently nesting in the same habitat. Niche partitioning based on prey taxa occurred regardless of the habitat preference. It was also found that differences in the size of wasps reflected distinctions in the size of their prey.4. These findings were consistent over the years, showing that the significance of specialisation in foraging activities and physical constraints during prey capture can play key roles in the coexistence of sympatric species. The distinctions in the foraging strategies of these wasps are discussed, as well as potential mechanisms driving the evolution in prey specialisation, with insights for future studies.

Predation avoidance behavior and web investment are not constrained by individual nutritional status in a shelter-building spider species

“…This behavior allows the reuse of proteins from the old web, which results in energy saving during the process of constructing new traps (Blackledge et al 2009). Orb-web spiders that build more persistent webs generally build shelters, which serve as protection from predators (Manicom et al 2008;Moura et al 2019).…”

“…Therefore, spiders can adopt foraging strategies to minimize the exposure time outside the shelter in periods of higher activity of their predators (Scharf et al 2011;Pekár 2014). Most predators are visually oriented and diurnal, such as birds (Gunnarsson and Wiklander 2015), lizards (Spiller and Schoener, 1988), hunting wasps from the Crabronidae family, specialized in capturing spiders (Moura et al 2019), as well as other spider species (Moura et al 2016;Meira et al 2021). Therefore, shelter-building spiders are more likely to be predated when capturing prey outside the shelter during the day.…”

Individual diet specialization in the spider Tidarren haemorrhoidale (Bertkau, 1880) (Theridiidae)

“…Animal species can exhibit distinct levels of specialization in resource use. Even the diet of closely related animal species can present a wide variation, ranging from one or a few food items (stenophagy) to a wide range of resources (euryphagy) (Hardy & Otto, 2014; Moura et al, 2019; Terraube et al, 2011). Similar patterns can be expected from individuals of the same species since intraspecific competition for similar prey types is usually more intense than interspecific competition (Araújo et al, 2011; Bolnick et al, 2003).…”

Never forget where you came from: Microhabitat of origin influences boldness and exploration in the hermit crab Clibanarius symmetricus (Diogenidae)

“…Populations may differ in behavioral traits because of local ecological conditions and genetic variation (Moura et al, 2019;Sugg et al, 1996). These behavioral differences can also be consistent within a population (Dall et al, 2012;Réale et al, 2007).…”