Resistance to Chalkbrood Disease in Apis mellifera L. (Hymenoptera: Apidae) Colonies with Different Hygienic Behaviour

Chalkbrood disease affects the larvae of honeybees Apis mellifera L. and is caused by the fungus Ascosphaera apis. Infected larvae die when they are stretched in the cap cell and suffer a gradual hardening that ends in a very hard structure (mummie). Several studies have demonstrated that colonies that express an efficient hygienic behaviour (uncapping of cell and subsequent removal of dead brood) exhibit a higher resistance to the disease. However, it remains unclear whether the advantage of hygienic colonies over less hygienic ones lies in the ability to remove mummies or in the early detection of infected larvae and its cannibalization before they harden. To elucidate this aspect, the hygienic behaviour of 24 colonies, which were subsequently provided with pollen cakes containig A. apis, was evaluated. The number of mummies and the number of partially cannibalized and whole larvae in uncapped cells were recorded. The most hygienic colonies controlled the disease better. These colonies also had a higher tendency to uncap cells that contained infected larvae and cannibalize them. The presence of A. apis in partially cannibalized and whole larvae in uncapped cells indicate that the advantage of hygienic colonies over less hygienic ones lies in the early detection of infected larvae death and their quick removal from the cell before they become mummies.

Efeito da qualidade da água no ciclo de vida e na atração para oviposição de Aedes aegypti (L.) (Diptera: Culicidae) / The effect of water quality in the life cycle and in the attraction for the egg oviposition of Aedes aegypti (L.) (Diptera: Culicidae)

The present research aimed at evaluating the influence of the water quality in the life cycle and attraction of Aedes aegypti (L.) females to oviposit using different sources of water (raw sewage, effluent of UASB reactor, effluent of polishing lagoon, effluent of anaerobic filter, rain water and de-chlorinated water). The immature development time and survivorship were evaluated on a daily basis in two distinct feeding systems (with and without food). The quality of the water was shown to affect the egg and larval stages, but not the pupal or the adult. In the absence of food, no development was observed in rain water and de-chlorinated water. Immature development was faster in water sources from raw sewage, although with the lowest survivorship (37.3 percent). Free-choice tests indicated that females preferred to lay most of their eggs on water collected from the effluent of a UASB reactor, achieving the highest oviposition activity index (OAI) of 0.57. In non-choice tests, females laid larger batches of eggs in water collected from anaerobic filters (204.8 eggs), with the lowest number of eggs being laid on de-chlorinated water (37.3 eggs). It can be concluded that A. aegypti does not demonstrate any particular preference to lay eggs on clean water. This has serious implications for developing strategies to manage populations of this important vector in urban areas as it was shown to lay eggs and successfully develop on several different sources of water.

Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowing behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae)

The sandfly Lutzomyia longipalpis (Lutz & Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L.longipalpis on a soil substrate when exposed to the fire ant Solenopsis invicata (Westwood). When ants were absent, most larvae tended to remain at or close to the soil surface, but when ants were present the larvae burrowed into the soil. Sandflies seek refuges in the presence of generalist predators, thus rendering them immune to attack from many potential enemies.

Reflexões sobre o consumo responsável / Reflections on responsible consumption

Aborda desde a espetaculização dos alimentos promovida pela indústria agroalimentícia; o consumo irresponsável que coloca o planeta em risco; a relação entre a agricultura e os fenômenos da subalimentação e da fome; até a discussão da necessidade de promover uma política de consumo sustentável que leve em conta a realidade dos limites ecológicos da Terra, que promova justiça social e que seja politicamente viável.

A infância e seus destinos no contemporâneo / Influence and his his destines in contemporary

Partindo de uma concepção construcionista da infância, este artigo discute a afirmação de uma morte da infância no contemporâneo, frente às transformações que tendem a minimizar as diferenças entre adulto e criança. Pretende-se aqui neste trabalho exercitar novas possibilidades de se narrar a infância num duplo desdobramento: que estas narrativas possam localizar novas produções subjetivas dentro das mudanças histórico-culturais; e que a tentativa de se pensar o novo no contemporâneo possa também ser acompanhada de uma crítica cultural, ou seja, uma visão ético-política sobre nossa época.

Departing from a constructionist approach on childhood, this paper dis-cusses the issue of the death of childhood in contemporary times once thetransformations that tend to minimize differences between adults and chil-dren are taken into account. In this paper new possibilities to narrate child-hood are set forth in a twofold implication: first of all, that these narrativescan figure out new subjective productions as engendered by the historicaland cultural conditions of our times; secondly, that the attempt to thinknew productions can set in motion a critical perspective, that is, an ethicaland political outlook on our contemporary situation.

Comportamento adjunto: controvérsias e contribuições teóricas / Adjunctive behavior: controversial issues and theoretical contributions

A área de investigação sobre comportamento adjunto, cujas pesquisas tiveram início na década de 60, é extensa e controvertida. O presente trabalho analisa as interpretações mais importantes do fenômeno, e mostra que diversas características apresentadas como próprias do comportamento adjunto também estão presentes em outros comportamentos. Falk interpretou o comportamento adjunto como atividade deslocada, Staddon como comportamento induzido por esquema, Timberlake como parte de um sistema comportamental pré-programado, e Wetherington questionou a existência de uma terceira classe de comportamento. Conclui-se que as tentativas de sistematização, têm se mostrado incompletas devido à diversidade de topografias de comportamentos adjuntos e a sua dependência de variáveis tanto do esquema como da espécie e do ambiente.