RESUMO
In environments undergoing constant transformation due to human action, such as deforestation and urbanization, the emergence of pests has become a challenge for agriculture and human welfare. In Brazil, over a thousand tonnes of pesticides are used annually, causing serious environmental damage such as the decline of insect populations. It is necessary to search for control alternatives in order to reduce the environmental impact caused by insecticides. This review aims to describe the use of social wasps as agents of biological control, focusing on the perspectives of their use in small farms and urban gardens, and to discuss the benefits of using this method. Studies have shown that 90-95% of the prey captured by wasps in small crops is made of leaf-eating caterpillars. In urban gardens, wasps diversify their prey, among which potential disease vectors, such as dipterans, stand out. We outline techniques for managing social wasp colonies in small farm and urban garden settings, including the use of artificial shelters. Among the advantages of using wasps as control agents, we highlight the practicality of the method, the low operational cost, the absence of prey resistance and the decrease of the use of insecticides.
RESUMO
The sterile insect technique (SIT) is a key element for the integrated management of pest populations of the Mexican fruit fly, Anastrepha ludens, in Mexico. Its success depends on the survival of mass-reared sterile males and their ability to mate with wild females. However, colonization and mass-rearing conditions can adversely affect their ability to avoid predators. To test if colony management strategies could contribute to improve field survival abilities of mass-reared flies, we compared the survival of males exposed to the orb-weaver spider Argiope argentata. Males compared originated from three strains with different colonization strategies: (a) a colony started from field-collected wild flies (replacement), (b) a colony started by hybridizing wild males with mass-reared adapted females (hybrid) and (c) a colony started with mass-reared males selected on the basis of their survival ability and mating competitiveness in field cages (selected). Mass-reared males and wild males were used as controls. Males were exposed to spiders under laboratory cage conditions. Overall, wild males showed better survival ability than mass-reared males. Regarding the colonization approach, wild males survived better than a hybrid, replaced and selected males. We conclude that mass-rearing conditions have a strong negative effect on the ability of males to escape spiders. The colonization systems evaluated did not counter this effect. The lower survival of males from the selected colony suggests that the selection over one generation did not contribute to improve males' predator avoidance and escape abilities and probably needs to be modified. Possible explanations for this and implications on colonization and colony management for SIT purpose are discussed.
Assuntos
Criação de Animais Domésticos/métodos , Comportamento Predatório , Aranhas/fisiologia , Tephritidae/fisiologia , Animais , Quimera , Feminino , Masculino , Controle Biológico de Vetores , Comportamento Sexual Animal , Tephritidae/genéticaRESUMO
The effect of routine captive procedures on the welfare of species used as experimental models in biomedical research is of great interest, since stress may alter the generalization and interpretation of results. This study investigated behavioral and endocrine (fecal cortisol) reactivity patterns in common marmoset (Callithrix jacchus) adult males (N = 10) and females (N = 9) subjected to three types of routine procedures in captivity: (1) moving to a same-sized cage (P1), to a smaller cage (P2), and (2) first-time pair formation (P3). Sexually dimorphic cortisol responses were detected in animals submitted to a physical environmental stressor (cage change). Females showed an increased response throughout P1, in relation to baseline (BP) cortisol, and a trend during P2. Males increased cortisol only during P2. On the other hand, males and females showed a similar endocrine response when management involved social challenge (pair formation), with both sexes increasing cortisol levels, but females exhibited a more intense and longer-lasting cortisol increase. Males and females exhibited similar behavioral responses to cage change, except for autogrooming, with males decreasing this behavior in P1. Only females demonstrated a significantly higher increase in piloerection frequency than that of males during the pair formation phase. These endocrine and behavioral changes must be taken into account when interpreting research data that involve these types of procedures. Further studies on the impacts of routine colony management are required to devise and include protocols in official husbandry guidelines.