A scientific note: Foragers deposit attractive scent marks in a stingless bee that does not communicate food location

Abstract

Scent marking of profitable food sources improves foraging efficiency and helps social bees meet colony demands for unpredictable floral resources (Giurfa and Nunez, 1992). Sophisticated marking has evolved in the stingless bees (Apidae, Meliponini); several genera recruit nestmates to profitable food sources with scent signals (reviewed in Nieh, 2004). Scent cues such as “footprints” (Wilms and Eltz, 2008) can also facilitate navigation and orientation to rewarding parts of food patches. Scent marks may improve colonies’ competitive ability, especially in the tropics, where social bee abundance and diversity are high. We assessed scent mark use by the stingless bee Melipona quadrifasciata. This species poorly communicates to nestmates the location of rich food sources (Jarau et al., 2000), thus could benefit from within-patch orientation information provided by attractive odor marks. However, its ability to deposit and use fieldbased information is not known. We studied four Melipona quadrifasciata anthidioides colonies at the Universidade de Sao Paulo, Ribeirao Preto in July 2007, and July– August 2008, using feeder choice tests (see, for example, Hrncir et al., 2004). To begin a trial, we allowed foragers trained to feed on 1.5 M sucrose solution to recruit 15 nestmates not previously used in the experiment. The 15 bees freely fed at a “visited” feeder for 10 min, during which we counted the number of visits. Next, we aspirated all bees and replaced the original apparatus with the visited and clean feeders on clean tripods, separated by 30 cm.