ABSTRACT
The myrmecophile larva of the dipteran taxon Nothomicrodon Wheeler is rediscovered, almost a century after its original description and unique report. The systematic position of this dipteran has remained enigmatic due to the absence of reared imagos to confirm indentity. We also failed to rear imagos, but we scrutinized entire nests of the Brazilian arboreal dolichoderine ant Azteca chartifex which, combined with morphological and molecular studies, enabled us to establish beyond doubt that Nothomicrodon belongs to the Phoridae (Insecta: Diptera), not the Syrphidae where it was first placed, and that the species we studied is an endoparasitoid of the larvae of A. chartifex, exclusively attacking sexual female (gyne) larvae. Northomicrodon parasitism can exert high fitness costs to a host colony. Our discovery adds one more case to the growing number of phorid taxa known to parasitize ant larvae and suggests that many others remain to be discovered. Our findings and literature review confirm that the Phoridae is the only taxon known that parasitizes both adults and the immature stages of different castes of ants, thus threatening ants on all fronts.
Subject(s)
Ants/parasitology , Diptera/physiology , Host-Parasite Interactions/physiology , Larva/parasitology , Animals , Brazil , Female , Predatory Behavior/physiology , Symbiosis/physiology , Trees/physiologyABSTRACT
Ants are among the most common arthropods that colonize termite nests. The aim of this study was to identify the ant fauna associated to termite nests found in a cacao plantation in the county of Ilhéus, Bahia, Brazil, with emphasis on the fauna that uses the nests as foraging and/or nesting environment. For this purpose, 34 active, decadent and abandoned nests of Nasutitermes corniger, N. ephratae and Nasutitermes sp., with different volumes and degrees of activity, were dissected. A total of 54 ant species, belonging to 23 genera and five subfamilies, was found in the constructions. The active, decadent and abandoned termite nests presented, respectively, six, eight and 48 ant species. Crematogaster acuta and Ectatomma tuberculatum were the most frequent species in the active and decadent nests, respectively, while the most frequent species in the abandoned nests were Solenopsis pollux, Thaumatomyrmex contumax and Thaumatomyrmex sp. Twenty-six ant species had true colonies within the termitaria. The Formicidae species richness in the nests was inversely related to the degree of termite activity in the nests. The occurrence of living, decadent or abandoned termitaria of Nasutitermes spp. in cacao plantations foments the heterogeneity of habitats available in the plantations and favors the maintenance of high diversity of organisms that use obligatory or opportunistically this substrate.
As formigas estão entre os mais comuns artrópodes colonizadores de ninhos de térmitas. Este estudo teve como objetivo identificar a mirmecofauna associada a ninhos de térmitas encontrados em um cacaual no município de Ilhéus, Bahia, Brasil, com ênfase na fauna que utiliza os ninhos como ambiente de forrageio e/ou nidificação. Para tanto, 34 ninhos ativos, decadentes e abandonados de Nasutitermes corniger, N. ephratae e Nasutitermes sp., com diferentes volumes e graus de atividade, foram analisados. Um total de 54 espécies de formigas, pertencentes a 23 gêneros e cinco subfamílias, foi encontrado nas construções. Os ninhos de térmitas em atividade, decadência e abandonados apresentaram, respectivamente, seis, oito e 48 espécies de formigas. Crematogaster acuta e Ectatomma tuberculatum foram as espécies mais freqüentes nos ninhos em atividade e em decadência, respectivamente. Nos ninhos abandonados, as espécies mais freqüentes foram Solenopsis pollux, Thaumatomyrmex contumax e Thaumatomyrmex sp. Vinte e seis espécies de formigas possuíam colônias verdadeiras dentro dos termiteiros. A riqueza de espécies de Formicidae nos ninhos mostrou-se inversamente proporcional ao grau de atividade dos térmitas nos ninhos. A ocorrência de termiteiros ativos, em decadência ou abandonados de Nasutitermes spp. em cacauais amplia a heterogeneidade dos habitats disponíveis nas plantações e favorece a manutenção de uma elevada diversidade de organismos que utilizam obrigatoriamente ou oportunamente esse substrato.
