ABSTRACT
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.
Subject(s)
Animals , Diptera/physiology , Predatory Behavior/physiology , Smell/physiology , Visual Perception/physiologyABSTRACT
A survey of attitudes, practices and perceptions of urban dwellers in Rio Claro, state of São Paulo, regarding insect pest problems and perticide usage was compared with a similar study from the US. Brazilians used urban pesticides more frequently than Americans. Americans noted more insect problems in gardens and sought professional help more often than Brazilians. Americans were generally better informed on pesticide usage and were more satisfied with their effectiveness than Brazilians. Americans changed their attitudes with respect to pesticides more than Brazilians. Of those who said they liked insects, beneficial reasons dominated for Americans while their esthetic value dominated for Brazilians. Brazilians cited honeybees, form honey, and butterfiles, for esthetics, more frequently than Americans, who considered predatory insects and spiders as being more beneficial. This survey indicates a general lack of knowledge of residential pesticide usage and of the economic and ecological importance of insects in urban Brazil.