Adaptive behavior of Scotocryptus melitophilus Reitter (Coleoptera, Leiodidae) to live with its host Melipona quadrifasciata Lepeletier (Hymenoptera, Apidae)

Abstract

ABSTRACT. Forty six beetles Scotocryptus melitophilus Reitter, 1881 collected in a nest of Melipona quadrifasciata Lepeletier, 1836 were studied. All beetles were put together in a large petri dish with 14 males, 14 virgin queens and 14 workers of M . quadrifasciata, which was not aggressive towards the S. melitophilus and flew with 3 to 10 beetles attached to them. When groups of 20 workers, 20 males and 20 virgin queens were put separately in three petri dishes, the workers become attractive to beetles afier they were seven days old, while the males afier the 19 days old. Only one virgin queen five days old attracted one beetle. The anatomic parts ofthe workers bees more attractive to the beetles when smeared to a filter papel" were the head (32%), abdomen (29%) and legs (29%). The part of the workers bees that less attracted the beetles was the thol"ax (10%). S. melitophilus, both males and females , are able to distinguish caste, sex and age differences of their host M. quadrifasciata, what can increase the adaptive value ofthe beetles involved in phoretic behavior. KEY WORDS. Scotocryptus, Melipona, adaptive behavior, phoresy, casteComparing ants and termites with social wasps and bees, the number of symbionts is large in the first two groups, whose majority are ground dwellers, and small in the last two groups (WILSON 1971;KISTNER 1982). However, the high-social stingless bees (Apidae, Meliponini) seem to be an exception to this rule. Their nests have many guests as mites, moths, cockroaches, flies, beetles, fungi and bacteria, some of they are obligate symbionts (WASMANN 1904;SALT 1929;NOGUEIRA-NETO 1970;MACHADO 1971;FLETCHMAN&CAMARGO 1979;ApONTE 1996; KERR et aI. 1996).Beetles associated with bees can be classified into two categories: a) parasites and predators and b) those that use the by-products ofthe bee's activities, such as honey, pollen, wax, fungi, propolis and garbage (YANEGA & LESCHER 1994 & WHEELER 1982). The melittophilous Scotocryptus are quite different from the other genera of Leiodidae because they are blind and flightless, lacking membranous wings. Some parts oftheir body (head, antennae and legs) can be folded and their tibiae rest in grooves on the femora. The median part of each mandible has a deep groove that allows the beetle firmly grasp onto the legs ofthe bees (ROUBIK & WHEELER 1982). Ali these characters facilitate their retention on the host's body, aIlowing the beetles to be moved phoreticaIly, their only way of dispersing from one host nest to another (WASMANN 1904;NOGUEIRA-NETO 1970; ROUBIK & WHEELER 1982). Their larvae also exhibit some adaptations for inquilinism, as dorso-ventral body compression and 10ss of stemmata (WHEELER 1985). The surface of the larva body is covered with strong setae that can help it not be threw out ofthe hive by the "garbage bee 2", that is the bee who gets the garbage from the "garbage mound" and takes it to the outside. A stingless bee colony profits from the Scotocryptus population, since it reduces the amount of garbage in the nest (ROU...

Two new species of the melittophilous beetleScotocryptus (Coleoptera, Leiodidae) associated with colonies ofMelipona fuscipes (Hymenoptera, Apidae) in Colombia

“…For example, larvae are blind, dorso-ventrally compressed, and are densely covered with stout hairs (Wheeler 1985); adults are rounded and compact, lack eyes and wings (Figs 1-16), and their mandibles are notched to allow them to grasp the legs of the bee during phoretic dispersal (Roubik & Wheeler 1982;Peck 2003). Scotocryptus adults can distinguish caste, sex, and age of their commensal bees and, therefore, can increase the opportunities to disperse (Bezerra et al 2000).…”

Ferramentas auxiliares na identificação de espécies de abelhas Meliponini, com ênfase no gênero Schwarziana (Lepeletier, 1836)

“…Os ninhos por nós coletados se encontravam em média de 1,0 m a 1,5 m abaixo do solo, e em algumas ocasiões alguns pequenos besouros da família Leiodidae estavam presentes junto à colônia. Bezerra et al (2000) descreveu o comportamento forético de coleópteros desta mesma família com colônias de Melipona quadrifasciata. No caso de Schwarziana, acredita-se tratar de uma relação comensal entre duas espécies de insetos, onde o pequeno coleóptero se beneficia alimentando-se do lixo produzido pela colônia (Imperatriz-Fonseca, informação pessoal).…”