Warwick Estevam Kerr

Comparative anatomy of the male reproductive internal organs of 51 species of bees

The anatomy of the internal organs of the male reproductive apparatus (MRA) of adults and pupae was compared among 51 species of bees, including representatives of six families. Four different types of MRA were found. The type I is present in males of the less derived families (Colletidae, Andrenidae, and Halictidae) and is characterized by three seminiferous tubules per testis, which are almost completely enveloped by the scrotal membrane. The type II is an intermediary between types III and I and is present in Melittidae and Megachilidae, as well as in some Apidae studied, being characterized by post-vesicular deferent ducts outside the scrotal membrane and by three or four seminiferous tubules per testis, except for Apis mellifera L., which has a secondarily increased number of tubules. Type III was only found in the Apidae studied and is characterized by separately encapsulated testes and genital ducts (except for the post-vesicular deferent duct). Accessory glands are well developed, and the ejaculatory duct is thickened with fissures in its wall, which may also occur in the type II. Type IV is present exclusively in the tribe Meliponini, and is characterized by the absence of accessory glands.

Plantas nectaríferas utilizadas por duas espécies de Melipona da Amazônia

Analisa-se o nectar de 302 abelhas de Melipona seminigra merrillae Cock. e 302 de abelhas de Melipona rufiventris paraensis Ducke, durante o periodo de maio de 1977 a abril de 1978, em Manaus. Do total de amostras estudadas de M. seminigra e M. rufiventris, 16 (5,3%) e 11 (3,6%) respectivamente, nao continham polen. Das 286 restantes (94,7%) de M. seminigra, 80 (28%) apresentavam polen de uma so especie, 88 (30,8%) de duas especies e 118 (41,2%) de tres ou mais. De 291 (96,4%) restantes de M. rufiventris, 33 (11,3%) apresentavam polen de uma so especie, 54 (18,6%) de duas especies e 204 (70,1%) de tres ou mais. Os graos de polen encontrados nas amostras de nectar representam ao todo 60 tipos morfologicos, distribuidos em 29 familias, pelo menos 42 generos diferentes, dos quais 39 foram separados ao nivel de especie. Sugere-se que a maior porcentagem de visitas, a mais de uma especie de plantas nectariferas (72%) do que a plantas poliniferas (39%), seja devida a estrategias das plantas unissexuais para obrigar a abelha visitar plantas masculinas para polen na manha e femininas para nectar mais tarde.

Correlation Between Amounts of 2-Heptanone and Iso-Amyl Acetate in Honeybees and their Aggressive Behaviour

SummaryIn honeybee workers derived from Italian and African stock, high concentrations of 2-heptanone in the mandibular glands were found to be positively correlated with several manifestations of aggressive behaviour at the hive entrance. Amounts of iso-amyl acetate from the sting apparatus were also assayed, but correlations with behavioural characters were not significant.

Protective effects of proanthocyanidins of grape (Vitis vinifera L.) seeds on DNA damage induced by Doxorubicin in somatic cells of Drosophila melanogaster

Proanthocyanidins (PAs), also known as condensed tannins, are naturally occurring oligomers and polymers of flavan-3-ol monomer units widely found in the leaves, flowers, fruits, seeds, nuts and barks of many plants. Grape seed proanthocyanidins (GSPs) have been used as nutritional supplements, as antioxidants, in preventing atherosclerosis and cardiovascular diseases, and for dislipidemy treatment. The anthracycline antibiotic adriamycin (Doxorubicin, DXR) is a cancer chemotherapeutic agent that interferes with the topoisomerase II enzyme and generates free radicals. In the present study, GSPs (1.680, 3.375, or 6.750 mg/mL) alone were examined for genotoxicity, and combined with DXR (0.125 mg/mL) for antigenotoxicity, using the standard (ST) and high bioactivation (HB) versions of the wing somatic mutation and recombination test in Drosophila melanogaster. The results observed in both crosses were rather similar. GSPs themselves did not show genotoxicity at the doses used. GSPs suppressed the DNA damage induced by DXR in a dose-dependent manner. Comparison of the frequencies of wing spots in the marker-heterozygous (MH) flies and balancer-heterozygous (BH) flies from both crosses, indicated that induced recombination was the major response for the treatments with DXR alone. The co-treatments demonstrated that GSPs have some anti-mutagenic activity; however, anti-recombinagenic activity was the major response.

Sex Determination in Bees (Apinae)

SUMMARYInbred lines of 7 species of social bees were studied, and checked for the presence of diploid male larvae: 7 lines of Apis mellifera, and 15 of Meliponini, representing 6 species. In 3 lines of Apis mellifera showing 50% viability, the non-surviving larvae were males, but diploid males could have some female-like characters. None of the species of Meliponini showed 50% mortality of brood, or 50% diploid males. The bearing of these results on the theory of sex determination in Apinae is discussed.

Pollination by Sexual Mimicry in Mormolyca ringens: A Floral Chemistry that Remarkably Matches the Pheromones of Virgin Queens of Scaptotrigona sp.

The chemical composition of some volatile (2-heptanol) and nonvolatile constituents (a homologous 9-alkene/alkane series) of Mormolyca ringens flowers and Scaptotrigona sp. queen waxes (homologous 9-alkene/alkane series) and cephalic extracts (homologous series of 2-alkanols, including 2-heptanol) involved with the pseudocopulation or sexual mimicry in Orchidaceae pollination is compared. The similarity in chemical composition of flowers and insects is assigned to the chemically induced copulatory activity in Scaptotrigona males.

Uma reflexão sobre o processo de avaliação das pós-graduações brasileiras com ênfase na área de saúde coletiva

Este artigo busca promover uma reflexao acerca dos criterios adotados pelo sistema de avaliacao da Pos-graduacao em curso no pais e seu impacto no âmbito dos diferentes programas, conferindo destaque na analise a area de Saude Coletiva. Ressalta-se, por um lado, a importância que os processos avaliativos tem na consolidacao do sistema de ensino e pesquisa, contribuindo, de modo decisivo, para a promocao e monitoramento da sua qualidade. Em contrapartida, os autores convidam a uma reflexao sobre a concepcao de ciencia subjacente aos criterios adotados e seu impacto no conjunto dos cursos que compoem a pos-graduacao em Saude Coletiva. Para tanto, apontam obstaculos situados em planos distintos e as desigualdades, nao apenas regionais, mas entre instituicoes geograficamente proximas mas que desenvolvem suas praticas em contextos distintos. O texto finaliza indagando sobre a correspondencia entre o percurso historico e os compromissos que marcam a trajetoria da Saude Coletiva e os rumos atuais da avaliacao da pos-graduacao nesse campo de saberes e praticas.

Genetic divergence in Tetragonisca angustula Latreille, 1811 (Hymenoptera, Meliponinae, Trigonini) based on rapd markers

One of the commonest neotropical stingless bees is Tetragonisca angustula (Latreille, 1811), popularly known in Portuguese as jatai, which occurs in variable nesting sites from Mexico to Argentina. We used 18 primers to generate 218 RAPD markers which we used to determined the genetic distance between T. angustula populations from 25 localities in three different Latin America countries, using Tetragonisca weyrauchi from the Brazilian state of Acre and the common honey bee (Apis mellifera) as outgroups. Genetic distance, calculated as the Percentage of Dissimilarity (14%), based on all markers divided the T. angustula population into eastern (group 1) and western (group 2) groups. However, we were able to separate the two groups by using only two primers that have generated five specific molecular markers. The eastern group consists of T. angustula angustula which occurs from Panama to the Brazilian states of Maranhao and northern Minas Gerais and has spread through the Brazilian Atlantic Forest as far as the southern Brazilian state of Santa Catarina. Group 2 is made up of T. angustula fiebrigi which has a more southerly and western distribution, occurring only in the western Brazilian states of Mato Grosso and Mato Grosso do Sul as well as the west of some other Brazilian states (Goias, Minas Gerais, Sao Paulo, Parana and Santa Catarina) and northeastern Argentina.

Circulating hemocytes from larvae of Melipona scutellaris (Hymenoptera, Apidae, Meliponini): cell types and their role in phagocytosis.

Infection in insects stimulates a complex defensive response. Recognition of pathogens may be accomplished by plasma or hemocyte proteins that bind specifically to bacterial or fungal polysaccharides. Several morphologically distinct hemocyte cell types cooperate in the immune response. Hemocytes attach to invading organisms and then isolate them by phagocytosis, by trapping them in hemocyte aggregates called nodules, or by forming an organized multicellular capsule around large parasites. In the current investigation the cellular in the hemolymph third instar larvae of M. scutellaris has been characterized by means of light microscopy analysis and phagocytosis assays were performed in vivo by injection of 0.5 microm fluorescence beads in order to identify the hemocyte types involved in phagocytosis. Four morphotypes of circulating hemocytes were found in 3rd instar larvae: prohemocytes, plasmatocytes, granulocytes and oenocytoids. The results presented plasmatocytes and granulocytes involved in phagocytic response of foreign particles in 3rd instar larvae of M. scutellaris.

Substituição natural de rainhas fisogástricas e distância de vôo dos machos em Tiuba (Melipona compressipes fasciculata Smith, 1854) e Uruçu (Melipona scutellaris Latreille, 1811) (Apidae, Meliponini).

This work reports on the reproductive life of the stingless bees (Meliponini). Old queens of Melipona compressipes fasciculata in Maranhao State, Brazil die and are successfully substituted by new ones in all months. Queens of Melipona scutellaris from Lencois (BA - northeastern Brazil) brought to Uberlândia (Central South eastern Brazil) died during all months, and there are no months where new queens are more able to begin egg laying. Forty males of M. scutellaris were marked in the thorax and released in groups of 10 at 100, 400, 800 and 1000 meters from the meliponary and their return to it was observed. All males released at 100 to 400 meters returned, 7 out of 10 and 2 out of 10 males returned respectively from 800 and 1000 meters. Males are constantly waiting for a virgin queen next to orphan colonies, the majority of the queens is inseminated in near the hive, therefore, gene dispersion depends more upon the males and of the occupation of a new cavity for nest.