Small-scale area effect on species richness and nesting occupancy of cavity-nesting bees and wasps

Abstract

Small-scale area effect on species richness and nesting occupancy of cavity-nesting bees and wasps. The research was conducted in an urban forest remnant in southeast Brazil. We tested the predictions of the following hypotheses: (1) larger areas present higher species richness of bees and wasps, (2) solitary bees and wasps occupy more nests in larger areas, (3) rare species occupy more nests in smaller areas. We sampled Aculeate bees and wasps using trap nests from February to November 2004. We placed trap nests in sampling units (SU) with different size (25, 100 and 400 m²) located in 6 ha of secondary mesophytic forest. One hundred and thirty-seven trap nests were occupied by seven species of bees and four species of wasps. We found an increase in wasp, but not bee species richness following increase in SU size. Hymenoptera richness (i.e. bees plus wasps) was also greater in larger SU. Both the number and density of occupied nests increased with SU size. The wasp Trypoxylon lactitarse responded significantly to area size, larger SU having more occupied nests. The same pattern was exhibited by the wasp Auplopus militaris, the Megachile bee species, and the bee Anthodioctes megachiloides. Only Trypoxylon sp. was not affected by SU size. Our results show that cavity-nesting bee and wasps respond differently to the area effects. Such findings must be complemented by information on the frequency and dynamics of area colonization and nest occupancy by species of solitary Hymenoptera.<br>Efeito de área em pequena escala sobre a riqueza e comportamento de nidificação de abelhas e vespas solitárias. Este trabalho foi realizado em fragmento florestal urbano localizado na região sudeste do Brasil. Foram testadas as predições das seguintes hipóteses: (1) áreas maiores apresentam maior riqueza de espécies de abelhas e vespas que nidificam em cavidades pré-existentes, (2) espécies de abelhas e vespas que nidificam em cavidades pré-existentes ocupam mais ninhos em áreas maiores, (3) espécies raras ocupam mais ninhos em áreas menores. Estes insetos foram amostrados por meio de ninhos-armadilha de fevereiro a novembro de 2004. As armadilhas foram dispostas em unidades amostrais com diferentes tamanhos (25, 100 e 400 m²), alocadas em um fragmento de floresta mesofítica de 6 ha. Cento e trinta e sete armadilhas foram ocupadas por sete espécies de abelhas e quatro espécies de vespa. Observamos um aumento na riqueza de vespas associado a uma maior área amostral; não observamos o mesmo para abelhas. A riqueza de espécies de Hymenoptera (abelhas e vespas, em conjunto) foi maior em áreas maiores. Tanto a abundância quanto a densidade de ninhos ocupados por abelhas e vespas aumentou com o aumento da unidade amostral. Trypoxylon lactitarse ocorreu mais frequentemente em áreas maiores. O mesmo padrão foi observado para Auplopus militaris, espécies do gênero Megachile e Anthodioctes megachiloides. Apenas Trypoxylon sp. não foi afetada pelo tamanho da unidade amostral. Os resultados do estudo mostram que abelhas e vespas solitárias respon...

Vertical diversity patterns and biotic interactions of trap-nesting bees along a fragmentation gradient of small secondary rainforest remnants

“…Most studies investigating whole communities of trap-nesting bees with large sample sizes in tropical countries have been done in agroecosystems or along land-use gradients (Klein et al 2002;Tylianakis et al 2005;Klein et al 2006), but few studies have investigated the trap-nesting bee communities in tropical forests (Morato and Campos 2000;Morato 2001;Thiele 2003;Loyola and Martins 2006;Loyola and Martins 2011). None of the studies investigated a fragmentation gradient that included different tree locations in order to measure edge effects of secondary forest remnants, which is important due to their potential for conservation and maintenance of ecosystem services for agricultural areas (Klein et al 2003;Brosi et al 2007a;Ngo et al 2013).…”

Trap-nesting solitary wasps (Hymenoptera: Aculeata) in an insular landscape: Mortality rates for immature wasps, parasitism, and sex ratios

“…in pre-existing cavities, the use of trap-nests has provided information not only on the occurrence of species in a given habitat, but also on the wasp community composition and their natural enemies, on the nesting biology of the species, on food sources used to rear the immatures (e.g., Krombein, 1967;Gathmann et al, 1994;Camillo et al, 1995;Camillo & Brescovit, 1999;Zanette et al, 2004;Tylianakis et al, 2006;Buschini et al, 2006;Asís et al, 2007;Buschini, 2007;Santoni & Del Lama, 2007;Buschini & Woiski, 2008;Ribeiro & Garófalo, 2010;Musicante & Salvo, 2010;Loyola & Martins, 2011;Polidori et al, 2011). Habitat quality, the effects of habitat fragmentation and of landscape complexity on community composition and predatory-prey interactions (Tscharntke et al, 1998;Morato, 2001;Steffan-Dewenter, 2002;Kruess & Tscharntke, 2002;Tylianakis et al, 2007;Loyola & Martins, 2008;González et al,2009;Holzschuh et al, 2009;Schüepp et al, 2011), and how urban environments can support such insects (Zanette et al, 2005) have also been assessed with the use of trap nests.…”

Islands in the desert for cavity‐nesting bees and wasps: Ecology, patterns of diversity, and conservation at oases of Baja California Peninsula

“…On the other hand, since trap‐nesting hymenopterans are spatially limited by available pre‐existing cavities, food, and physiological fly restrictions, local habitat configuration become crucial (Gathmann & Tscharntke, ; Loyola & Martins, ; Zurbuchen et al, ). This may partially support the striking contrast in abundance and species composition between oases and desert habitats, indicating that local conditions are playing a major role in the structure of their communities.…”