Phoresy on a Neotropical Bumblebee (Hymenoptera: Apidae) by Antherophagus (Coleoptera: Cryptophagidae)

On January 22, 1994, while collecting bumblebees in San Isidro, Costa Rica (702 m altitude), I observed a queen bumblebee (Bombus pullatus Franklin) carrying a beetle on her right leg and pollinating the flowers without any problem. I immediately caught the queen and her guest, and put them in an ethyl acetate killing jar where the beetle remained attached by its mandibles to the tibia of the right hind leg. The beetle (a female) which proved to be a new species of Antherophagus Latreille (Q.D. Wheeler & P. Fraissinet, pers. comm.) eventually released its hold in the killing jar. I found several records of this phoretic behavior in several North American bumblebee species Packard, 1864; J.B. Smith, 1909; Blatchley, 1910; Wheeler, 1919; Plath, 1934) as well as some European records (Redtenbacher, 1858; Carus and Gerstaecker, 1863; Eichhoff, 1866; Gorham, 1869; Perris, 1869-70; Bugnion, 1869-70; Seidlitz 1869-70; Hoffer, 1883; Fowler, 1889; Sharp, 1899; Wagner, 1907; Reitter, 1911; Sladen, 1912; Reuter, 1913; Alford, 1975), but to my knowledge this is the first record in a Neotropical bumblebee species. Although Crowson (1981) described an Antherophagus species associated with Bombus Latreille in Central America, he did not make any reference to the particular species involved. Also Roubik (1989) mentioned that Antherophagus apparently transfer between foraging Bombus at flowers. Antherophagus species have been found in nests of Bombus ephippiatus Say also in Costa Rica (Chavarrfa in prep.). But it is interesting to note that the author has collected three nests of Bornbus pullatus Franklin without beetles or any other ectosymbiont so in this case we can apply the term "phoresy." Since 1896 Lesne used