ABSTRACT
The semiochemicals produced by termites have been little studied compared to those of ants and bees. Among the limiting factors are the cryptic habits of termites, together with the difficulty in maintaining many species in the laboratory. The semiochemicals of Isoptera include trail, sex and alarm pheromones and a complex mixture of substances responsible for the recognition of nestmates. Although little is known about the semiochemicals of termites, available data indicate a strategy of pheromonal parsimony in the chemistry communication of these insects, i.e., the same compound is sometimes secreted by different glands, different species and for different functions.
Subject(s)
Isoptera/physiology , Pheromones/physiology , AnimalsABSTRACT
The semiochemicals produced by termites have been little studied compared to those of ants and bees. Among the limiting factors are the cryptic habits of termites, together with the difficulty in maintaining many species in the laboratory. The semiochemicals of Isoptera include trail, sex and alarm pheromones and a complex mixture of substances responsible for the recognition of nestmates. Although little is known about the semiochemicals of termites, available data indicate a strategy of pheromonal parsimony in the chemistry communication of these insects, i.e., the same compound is sometimes secreted by different glands, different species and for different functions.
Os semioquímicos dos cupins têm sido pouco estudados quando comparados aos de formigas e abelhas. Um dos fatores limitantes é o hábito críptico dos térmitas, aliado à dificuldade de manutenção de muitas espécies em laboratório. Entre os semioquímicos de Isoptera destacam-se os feromônios sexuais, de trilha, de alarme e uma mistura complexa de substâncias responsável pelo reconhecimento dos companheiros de ninho. Apesar de os semioquímicos dos cupins serem pouco conhecidos, os dados disponíveis indicam uma estratégia de parcimônia feromonal na comunicação química desses insetos, ou seja, algumas vezes o mesmo composto é secretado por diferentes glândulas, diferentes espécies e para diferentes funções.
Subject(s)
Animals , Isoptera/physiology , Pheromones/physiologyABSTRACT
Coptotermes gestroi is an exotic species of termite that is a pest of great economical importance in Brazil. This paper relates the occurrence of a coelomic gregarine (Apicomplexa: Neogregarinida) in the abdomen of the foraging workers recently collected from field colonies of this termite. The termite hosts presented large, white abdomens because they carried 1 up to 3 cysts of gregarines filled with numerous lemon-shaped spores. Earlier developmental stages of this gregarine were not observed in the scanning microscope preparations nor in the histological slides of the infected termites. However, the lemon-shaped spores suggest a parasite gregarine of Mattesia genus, family Lipotrophidae.
Subject(s)
Apicomplexa/pathogenicity , Isoptera/parasitology , Abdominal Cavity/parasitology , Animals , Apicomplexa/ultrastructure , Brazil , Spores, Protozoan/ultrastructureABSTRACT
The interaction between olfactory and visual cues in the landing responses of Chrysomya megacephala (Fabricius) was analyzed in a natural environment (grass) using three plain cardboard circles with the colors white, black and other being the own grass (control) with 30 cm in diameter. The circles were divided in four quadrants and five sectors using as bait 80 mg of carcass of fish and minced flesh put in the center. To check the interaction between visual and olfactory factors, we analyzed the relation among the direction of wind and the sectors, the quadrants and the color of circle where C. megacephala adults landed. In the presence of the black and white circles, flies landed closer to the central release point of the bait when the wind was present compared with the other control circle. The results show that while odor cues may enhance the induction of landing by C. megacephala, visual cues are important when selecting a final landing site. Improved understanding of this interaction may allow the development of more effective traps or targets, enhancing the control efficiency of these control devices.
Subject(s)
Diptera/physiology , Predatory Behavior/physiology , Smell/physiology , Visual Perception/physiology , AnimalsABSTRACT
A interação entre pistas visuais e olfativa na resposta de pouso de Chrysomya megacephala (Fabricius) foi analisada em ambiente natural. Para isso, foram utilizados três círculos planos de cartolina de cor branca, preta e outro com a própria grama (controle) com 30 cm de diâmetro. Os círculos foram divididos em quatro quadrantes e cinco setores circulares, tendo como isca 80 mg de carcaça de peixe e carne moída colocada no centro. Para verificar a interação entre as pistas visuais e a olfativa, foi analisada a relação entre a direção do vento e os setores, os quadrantes e a cor do círculo em que os adultos de C. megacephala pousavam. Na presença dos círculos preto e branco, as moscas pousaram mais próximo do ponto de liberação do odor das iscas quando o vento estava presente, em comparação com o círculo controle. Os resultados mostraram que a existência de odor pode melhorar a indução do pouso de C. megacephala e que pistas visuais são importantes para selecionar o local de pouso final. O entendimento dessa interação pode permitir o desenvolvimento de iscas e alvos mais efetivos, fortalecendo a eficiência de estratégias de controle.
The interaction between olfactory and visual cues in the landing responses of Chrysomya megacephala (Fabricius) was analyzed in a natural environment (grass) using three plain cardboard circles with the colors white, black and other being the own grass (control) with 30 cm in diameter. The circles were divided in four quadrants and five sectors using as bait 80 mg of carcass of fish and minced flesh put in the center. To check the interaction between visual and olfactory factors, we analyzed the relation among the direction of wind and the sectors, the quadrants and the color of circle where C. megacephala adults landed. In the presence of the black and white circles, flies landed closer to the central release point of the bait when the wind was present compared with the other control circle. The results show that while odor cues may enhance the induction of landing by C. megacephala, visual cues are important when selecting a final landing site. Improved understanding of this interaction may allow the development of more effective traps or targets, enhancing the control efficiency of these control devices.
