Trachypus elongatus (Fabricius, 1804), 1925

Pereira, Felipe Walter & Gonçalves, Rodrigo Barbosa, 2021, Behavior notes and prey spectrum of three species of the bee-hunting wasp Trachypus Klug (Hymenoptera: Apoidea), Papéis Avulsos de Zoologia 61, pp. 1-7 : 3

Trachypus elongatus (Fabricius, 1804)

We found a sum of 24 nests distributed in seven divisions: 86 (n = 2); 88 (n = 5); 91 (n = 2); 92 (n = 7); 97 (n = 5); 198 (n = 1); 416 (n = 2). Nests in divisions 86 and 88 were located in a part of the bank exposed to the sun in the morning and partially covered in the shade from a bus stop in the afternoon. Those in divisions 91, 92, and 97 were continuously exposed to sunlight all day, while in 198 and 416 were in banks predominantly covered by shadows from trees. The latter was on soil with higher humidity from dew. Females were active from November to March (late spring and summer). Circular statistics revealed a non-uniformly abundance distribution along the year, a significant seasonal pattern (n = 72 observations; p <0.05, Rayleigh (Z) test) was found with the mean vector in December ( Table 1; Fig. 2A ). Males were observed only in December 2018, flying over the nest sites, but no mating behavior was observed.

Nest excavations by the wasps stopped around 1 PM, then each female stayed in its respective nest and exhibited guard behavior, with the following female patterns: (i) closing the nest entrance with its head; (ii) exposing its head outside the entrance and opening its jaws whenever another individual (same species or not) appeared near the nest. Defense behavior (iii) occurred more frequently against T. taschenbergi females that tried to enter the nest and then immediately retreated, without conflict. No evidence of two or more females sharing the same nest was observed. Foraging and provisioning activities were observed from November until March. In one case, a female left the nest and returned more than 30 minutes later with a prey. In total, we sampled seven prey items, six workers and one drone of the stingless bee Trigona spinipes (Fabricius, 1793) .

Figures

Figure 2.Rose diagrams forseasonal activities of (A) Trachypus elongatusand (B) Trachypus taschenbergi,consideringthe number of female observations per day of fieldwork.Months are treated as sectors of 30 degrees each,with January corresponding to 0 and December to 330.