Stingless bees (Apidae: Meliponini) at risk in western Mexico

Stingless bees were sampled by direct search, following Sutherland’s (1996) proposal. At each site, two people searched for bees for a minimum of four to a maximum of six consecutive hours in an area of 2 Km2. Searching time differences depended on the number of bee species observed, if after four hours no more new bee species appeared we stopped the sampling in that site. Sampling days began 8-9 am depending on weather conditions. At each location we chose sites where flowering was evident, with water sources or salt deposits nearby. Bees were collected with entomological nets or entomological aspirators. We also considered information provided by local people about sites with bee aggregations, bee nests and floral patches. A single sampling session was performed at each site between February 2018 and June 2019. Because meliponine bees are active throughout the year, they were sampled when plants where flowering according to the type of vegetation and on days without rain or strong winds.