To understand the molecular mechanisms induced by stress that contribute to the development of tolerance in eukaryotic cells, the filamentous fungus Aspergillus nidulans has been chosen as a model system. Here, the response of A. nidulans germlings to heat shock is reported. The heat treatment dramatically increased the concentration of trehalose and induced the accumulation of mannitol and mRNA from the catalase gene catA. Both mannitol and catalase function to protect cells from different reactive oxygen species. Treatment with hydrogen peroxide increased A. nidulans germling viability after heat shock whilst mutants deficient in catalase were more sensitive to a 50 mC heat exposure. It is concluded that the defence against the lethal effects of heat exposure can be correlated with the activity of the defence system against oxidative stress.

Neotropical Entomology 37(5): 606-608 (2008) Conopídeos (Diptera: Conopidae) Parasitando Centris (Heterocentris) analis (Fabricius) (Hymenoptera:Apidae, Centridini) RESUMO -Parasitas de abelhas adultas são quase exclusivamente moscas e dentre os mais importantes estão os conopídeos. Nesta comunicação relata-se pela primeira vez a associação de espécies de Physocephala (Diptera: Conopidae) com Centris (Heterocentris) analis (Fabricius). De uma amostra de 26 fêmeas e nove machos da espécie hospedeira encontrados mortos em ninhos-armadilha vazios, no campus da Universidade de São Paulo, Ribeirão Preto, SP, emergiram 35 parasitóides pertencentes a nove espécies de Physocephala. Os dados mostram que C. analis é hospedeiro para várias espécies de conopídeos e sugerem que tais parasitóides podem desempenhar um papel importante na regulação populacional dessa espécie de abelha. PALAVRAS-CHAVE: Parasitismo, associação parasita-hospedeiro, abelha, ninhos-armadilhaABSTRACT -Parasites of adult bees are almost exclusively fl ies and the most important of them are conopids. This note registers for the fi rst time the association of species of Physocephala (Diptera: Conopidae) with Centris (Heterocentris) analis (Fabricius). From 26 females and nine males of the host species found dead inside trap-nests on the campus of the University of São Paulo, Ribeirão Preto, Brazil, 35 parasitoids were obtained belonging to nine species of Physocephala. The data show that C. analis is a host to several conopid fl ies, and suggest that such parasitoids can play an important role in population control of this bee species.

ABSTRACT. Influence of temperature on the immatures mortality of Centris (Heterocentris) analis (Hymenoptera, Apidae, Centridini). Centris (Heterocentris) analis (Fabricius, 1804) nests were studied at the University Campus of Ribeirão Preto, São Paulo, Brazil, from January to December 2003. The females constructed nests in trap-nests made with black cardboard introduced in wood blocks which were placed on the shelves of two shelters built at the study site: sunny area and shady area. In both areas, the immatures mortality occurred mainly in the egg stage; shady area: egg stage (76.7%), larval stage (10.0%) and pupal stage (13.3%); sunny area: egg stage (80.0%), larval stage (6.6%) and pupal stage (13.3%). The mortality difference between the areas (χ 2 = 1.0, gl:1, p>0.05) was not great enough to reject the possibility that the difference was due to random sampling variability, however, there were differences of temperature between two areas in all months observed (t-student, p<0.05) and the temperature around 26-27°C showed to be optimal to Centris analis development.

O objetivo deste trabalho foi identificar comportamentos de deposição de óleo realizados pelas fêmeas da abelha solitária Centris analis (Fabricius), parasitadas por Physocephala spp. Esse estudo foi realizado no Campus de Ribeirão Preto da Universidade de São Paulo, Ribeirão Preto, seguindo a metodologia de ninhos-armadilhas, nos quais as fêmeas construíram as células de cria em ninhos confeccionados com cartolina preta e introduzidos em blocos de madeira localizados em duas estantes na área de estudo. Das 26 fêmeas que nidificaram no local, 11 foram encontradas mortas dentro de ninhos-armadilha vazios. Depois foram levadas ao laboratório, juntamente com nove machos mortos, colocados em tubos de vidro e observados diariamente até a emergência do parasitoide Physocephala spp. (Diptera: Conopidae). Todos os ninhos construídos pelas fêmeas parasitadas receberam uma deposição extra de óleo sobre o fechamento da última célula de cria. Além disso, essas fêmeas permaneceram 5,4 dias no local depois de fecharem seus ninhos, realizando deposições extras de óleo sobre o fechamento de ninhos e fechando ninhos vazios (n = 42), sem células de cria. Os dados deste trabalho sugerem que as deposições de óleo pelas abelhas parasitadas, aumentam as dificuldades de sucesso de ataque do parasitoide Leucospis cayennensis Westwood, visto que existem dois obstáculos para superar: óleo sobre a última célula de cria e óleo sobre o fechamento do ninho. É importante salientar que defendendo os ninhos contra tais invasores, as fêmeas parasitadas que realizaram deposições extras de óleo possibilitariam uma nova geração de conipídeos.Oil Deposition by Females of Centris analis (Fabricius) (Hymenoptera: Apidae: Centridini) Parasitized by Physocephala spp. (Diptera: Conopidae)Abstract. The aim of this work was to identify behaviors of oil deposition by females of the solitary bee Centris analis (Fabricius) parasitized by Physocephala spp. This study was conducted at the Campus of the University of São Paulo, Ribeirão Preto, using trap-nests in which the females built the brood-cells in nests made with black cardboard, introduced in wood blocks that were placed on two shelves at site of study. From the 26 females that nested in the area, 11 were found dead inside the empty trap-nests. Next, they were taken to the laboratory together with nine dead males, placed in glass tubes and were observed daily until the parasitoid Physocephala spp. (Diptera: Conopidae) emerged. All nests built by the parasitized females had extra oil deposition on the last brood-cell occlusion. In addition, these females remained for 5.4 days at site of study after closing the nests, made extra oil depositions on the nest occlusions and closed 42 empty nests, without brood-cells. The data of this work suggest that the extra oil deposition by parasitized females, increase the difficulties to the success of the parasitoid Leucospis cayennensis Westwood, since there are 2 obstacles to be won: oil over the last partition and oil on the nest occlusion. It´s good to point out that defending the nests against parasitoids the females would be ensuring a new generation of conopids.