ABSTRACT
Abstract Galls are neoformed plant structures created by cell hyperplasia and hypertrophy induced by a number of organisms, especially insects. After adult insects hatch, senescent galls may remain on the host plant and be occupied by a succession of fauna, the most important and dominant being ants. This study aimed at characterizing the ant fauna successor of stem galls induced by microlepidoptera in Microgramma squamulosa (Kaulf.) de la Sota (Polypodiaceae). Four collections were carried out in the municipality of Nova Friburgo, Rio de Janeiro state, Brazil. The galls were packed in plastic bags and taken to the laboratory. Ants were euthanized and conserved in 70° GL alcohol and later identified. A total of 49 stem galls were collected and analyzed, 15 containing microlepidoptera galler larvae, one a parasitoid wasp and 33 without the microlepidoptera or parasitoid (67%). Twelve of these galls (39%) contained ants. Six ant species were recorded (Camponotus crassus, Crematogaster curvispinosa, Crematogaster sericea, Procryptocerus sampaioi, Tapinoma atriceps, and Wasmannia auropunctata), all native to Brazil. Ant occupation in M. squamulosa seems to be associated with senescent galls due to hatching of the galler insect, which leaves a hole that allows ants to colonize it, in other words, an opportunistic domatia. Senescent galls resulting from the death of galler insects do not seem to facilitate ant occupation.
ABSTRACT
ABSTRACT In this study we document for the first time flight patterns along a 24 h time range for an ant assemblage in one of the most diverse ecosystems on Earth, the Brazilian Atlantic Forest. Malaise traps were used to analyze the diurnal nuptial flights of a Neotropical ant assemblage during five days. Traps captured 802 individuals, revealing a remarkably high diversity (42 ant species), with samples strongly male biased (1:22). Contrariwise to similar studies, we found only a small proportion of species engaged in nocturnal nuptial flights, with diurnal flights accounting for an impressive 95% of all ant flight activity recorded. For the 18 most common species, three ant groups could be identified regarding flight period: sunrise, sunset, and continuous flight activity. Similarity analyses, however, suggest that closely related time ranges of flight activity may actually not be continuous. Further, three species showed pulsed flight activity, at varied hours of the day. Two species of Hypoponera showed flight activity at different periods of the day, suggesting congeneric staggered nuptial flights. Our results match long-term studies of ant assemblages showing high diversity of flight phenologies in hyperdiverse tropical ant assemblages and provide the first data on the reproductive phenology for several Neotropical ant species.