What do we know about Neotropical trap‑nesting bees? Synopsis about their nest biology and taxonomy

Abstract

Cavity-nesting bees are enigmatic because they are difficult to observe in the wild, hence trap-nests (man-made cavities) provide the means by which these bees may be studied. Trap-nests is an efficient methodology to study these bees and are common worldwide. These traps have been used for a variety of reasons, including inventories, to examine pollen load, to study habitat disturbance, and bee conservation. However Neotropical trap-nesting bees’ taxonomy and biology are still poorly known and here we provide a review about these subjects. We searched for trap-nest bee studies in the Neotropical Region using Google Scholar and ISI Web of Science at any time in the past to December 2017. We found 109 independent studies, most of which were from Brazil (87 studies), followed by Argentina (10 studies), and other countries had fewer than five studies each. A total of 140 species, 24 genera, 10 tribes and three subfamilies were reported in trap-nests. Nest architecture was described for only 49 species. Taxonomy is only well-known for 14 genera, somewhat known for seven and is essentially unavailable for three genera. Construction material, closing plug and cell shape are similar among species in the same tribes and genera. Vestibular and intercalary cells, and the preliminary plug are variable, even at the specific level. Apinae is the most studied group with available data for all genera recorded in trap-nests. Colletinae is the least-studied group and nothing is known for their nesting biology. Megachilinae is intermediate, with some studies of taxonomy and nesting. We suggest that further trap-nest studies should provide more detailed information on nest architecture and construction materials, including explicit mention of structures that are absent. All Neotropical bees need more taxonomic studies, but some, such as Hylaeus and Megachile, require more attention since Hylaeus is essentially unknown and Megachile is very common on trap-nests.

Unveiling the trap-nesting bees and wasps’ fauna (Hymenoptera: Apocrita) and associated organisms of the Jardim Botânico do Rio de Janeiro, Brazil

“…Several researches started to put this issue an account and some studies investigating the fauna of insects in cities have come up in the last years (Hernandez et al, 2009;Martins et al, 2013;Cardoso & Gonçalves, 2018;Rocha-Filho et al, 2020). Also, the methods used to assess the Hymenoptera fauna are manifold (Prado et al, 2017), but some may gather additional data associated with the species collected, such as the trap-nest method (Krombein, 1967;MacIvor, 2017;Staab et al, 2018;Costa & Gonçalves, 2019), which is interesting when one thinks on conservation and management, whether natural areas or urban areas. In Brazil, studies using this method started in 1978 (Serrano & Garófalo, 1978) and much research was developed using trap-nests, but most of them focused on natural or semi-natural areas, and few assessed urban areas (Hernandez et al, 2009;MacIvor, 2017).…”

Heterogeneous agroecosystems support high diversity and abundance of trap‐nesting bees and wasps among tropical crops

“…Cavity‐nesting bees and wasps are difficult to observe in the wild; hence, trap nests (man‐made cavities) provide the means by which these animals may be studied. Trap nests are an efficient methodology to study these bees and wasps and have been used for a variety of reasons, including inventories, to examine pollen load, habitat disturbance, enhance pollination services, and bee and wasp conservation (Costa & Gonçalves, 2019). This methodology allows one to know part of the fauna of hymenopterans of the neotropical region, which is poorly known (Costa & Gonçalves, 2019).…”

“…Trap nests are an efficient methodology to study these bees and wasps and have been used for a variety of reasons, including inventories, to examine pollen load, habitat disturbance, enhance pollination services, and bee and wasp conservation (Costa & Gonçalves, 2019). This methodology allows one to know part of the fauna of hymenopterans of the neotropical region, which is poorly known (Costa & Gonçalves, 2019). However, for a more complete view of bees and wasps that inhabit the Brazilian savannah, complementary sampling methods should be encouraged.…”

A study of the biology of Epicharis (Epicharoides) picta using emergence-traps

“…Centridini is a neotropical tribe of oil-collecting bees, composed of only two wellsupported monophyletic genera (Moure et al 2012;Bossert et al 2019) of solitary bees: Epicharis Klug, 1807, which dig their nests in the soil; and Centris Fabricius, 1804, composed mostly of some species that dig their nests in the soil or sometimes in termite nests (e.g., Rozen and Buchmann 1990;Gaglianone 2001;Aguiar and Gaglianone 2003;Rozen et al 2011) and some that use pre-existing cavities (e.g., Costa and Gonçalves 2019). Even though nesting habits tend to be constant in some species, Centris' nesting behavior has some plasticity (Vinson and Frankie 1991;Martins et al 2014).…”