ABSTRACT We compared the termite assemblages of different ecosystems in a humidity gradient. Three areas were sampled: (i) a humid montane forest; (ii) a hillside forest where shaded coffee (Coffea arabica Linnaeus, 1753) is cultivated; (iii) a seasonally dry forest (Caatinga). Active collection protocols were employed in each area during the dry and rainy seasons. The species were grouped according to their habitats and feeding habits. A total of 45 termite species belonging to 20 genera and three families were encountered. The termite fauna of the Caatinga was as rich and abundant as that of the humid forest areas, but it was distinct from it in species composition. Most termite species encountered in the montane forest were also found in the agro-ecological site, but some species were only found in the latter. The termite fauna of the Caatinga varied seasonally the most, with significantly reduced abundance during the dry period. When species richness, abundance, and species composition were considered together the climatic seasons were not found to significantly affect the termite faunas in any of the study areas. The numbers of encounters per feeding group and per habitat exploited did not differ among the different areas, or during the different seasons. Even in adjacent areas, the humidity gradient, as well as the vegetational characteristics, are reflected in differences in the termite fauna. Agro-ecological regimes can be considered viable alternatives to traditional methods of cultivation as they largely conserve the biodiversity found in non-modified environments.

Este trabalho teve como objetivo avaliar os efeitos de Metarhizium anisopliae, sobre Diatraea flavipennella e investigar sua resposta imune. Foi observado o efeito de M. anisopliae sobre lagartas de D. flavipennella, pulve-rizado nas concentrações de 103, 104, 105 conídios/mL, no qual apresentou diferenças com relação ao período larval, prolongando até 72,0 dias nos tratamentos e 25,0 dias na testemunha. Os resultados referentes aos hemócitos revelaram que as células mais frequentes quando pulverizado nas concentrações de 103, 105, 107 conídios/mL foram prohemócitos, esferulócitos, plas-mócitos e granulócitos, em relação aos adipohemócitos e oenocitóides. O nível de oxido nítrico apresentou diferença entre a testemunha e a concentração 107 conídios/mL (24h), enquanto a atividade de fenoloxidase foi semelhante entre os tratamentos em 24h e superior na concentração 107 conídios/mL (60h). No perfil bioquímico dos hemócitos, houve uma alteração em carboidratos, lipídios e proteínas em reação ao fungo. Os resultados indicam que o fungo M. anisopliae pode ser utilizado no Manejo Integrado de D. flavipennella, por apresentar patogenicidade e interferir no seu desenvolvimento mesmo quando expostas a pequenas concentrações.

This work aimed to evaluate the effects of Metarhizium anisopliae on Diatraea flavipennella and investigate their immune response. Was observed the effect of M. anisopliae against larvae of D. flavipennella sprayed at concentrations of 103, 104, 105 conidia / mL, in which showed differences relative the larval period, extending up to 72.0 days in treatment and 25.0 days in the control. The results for hemocytes revealed that the most frequent cells when sprayed at the concentrations of 103, 105, 107 conidia / mL were the prohemocytes, spherulocytes, plasmatocytes and granulocytes in relation to adipohemocytes and oenocytoids. The level of nitric oxide was different between the control and the concentration 107 spores / mL (24), while the activity of phenoloxidase was similar among treatments in 24 and higher concentration 107 spores / mL (60h). In biochemical profile of hemocytes was a change in carbohydrates, lipids and proteins in response to the fungus. The results indicate that the fungus M. anisopliae can be used in the Integrated Management of D. flavipennella by presenting pathogenicity and interfere with their development even when exposed to small concentrations.

O objetivo desta pesquisa foi caracterizar morfológica e ultraestruturalmente os hemócitos de operários de Nasutitermes coxipoensis (Holmgren) e quantificar os tipos celulares 24h, 48h e 72h após inoculação com Metarhizium anisopliae. Seis tipos de hemócitos foram identifi cados: plasmatócito, granulócito, esferulócito, prohemócito, adipohemócitos e oenocitóide. Nenhuma alteração na morfologia dessas células foi evidenciada durante os intervalos. Entretanto, houve variações na proporção dos hemócitos em relação à testemunha para esferulócitos, adipohemócitos e oenocitóides, nos três intervalos de avaliação, e para plasmatócitos e granulócitos no intervalo de 48h. As causas potenciais dessa variação e suas implicações são apresentadas e discutidas neste artigo.

We aimed to characterize the morphology and ultrastructure of hemocytes of Nasutitermes coxipoensis (Holmgren) workers and to quantify the cell types 24h, 48h and 72h after inoculation with Metarhizium anisopliae. Six hemocytes types were identified, plasmatocyte, granulocyte, spherulocyte, prohemocyte, adipohemocyte and eonocytoid Hemocytes did not present any morphological alteration at the several observation periods, but they did have a change in their abundance, as observed for spherulocytes, adipohemocytes and eonocytoids at all intervals, and for plasmatocytes and granulocytes at 48h after host inoculation. We argue on the possible reasons and implications of the observed changes.

A ação de Metarhizium anisopliae var. anisopliae e Metarhizium anisopliae var. acridum sobre o cupim de montículo Nasutitermes coxipoensis (Holmgren) e a produção de conídios sobre os insetos mortos foram estudadas em laboratório. Doses infectivas foram determinadas através do contato direto dos insetos com a cultura fúngica após 12 dias de crescimento e quantificação dos conídios em câmara de Neübauer. Foram utilizadas as doses 0,5 x 10(6) e 1,6 x 10(7) conídos/ml, para M. anisopliae var. anisopliae, e 1,4 x 10(5) e 1,8 x 10(6) conídios/ml para M. anisopliae var. acridum, nominadas dose A e dose B, respectivamente. As doses corresponderam a 3 min. e 15 min. de contato direto de 20 cupins com a cultura fúngica. A produção de conídios foi avaliada utilizando-se insetos inoculados com o fungo, 10 dias após a morte. Os bioensaios foram realizados em triplicata. Os percentuais de mortalidade acumulada de N. coxipoensis tratados com M. anisopliae, no terceiro dia após a inoculação, foram: controle, 15,7%; dose A 95,7% e dose B 100%; para M. anisopliae var. acridum foram: controle, 13,3%; dose A 66,4 e dose B 88,8%. A média da produção de conídios foi mais elevada para M. anisopliae var. anisopliae do que para M. anisopliae var. acridum. Os resultados mostraram que M. anisopliae var. anisopliae apresentou maior potencial para o controle biológico de N. coxipoensis.

The action of Metarhizium anisopliae var. anisopliae and Metarhizium anisopliae var. acridum on the mound termite Nasutitermes coxipoensis (Holmgren) and the conidia production on dead insects were studied in laboratory. Infective doses were determined through direct contact of the insects with the fungi cultures with 12 days of growth followed by conidia quantification in Neübauer camera. The doses of 0.5 x 10(6) and 1.6 x 10(7) conidia/ml of M. anisopliae var. anisopliae, and 1.4 x 10(5) e 1.8 x 10(6) conidia/ml of M. anisopliae var. acridum were named dose A and dose B, for each fungus, respectively. These doses corresponded to 3-min and 15-min direct contact of 20 insects with the fungi cultures. Conidia production was evaluated using the insects inoculated with fungi. The bioassays were carried out in triplicate. The percentage of accumulated mortality of N. coxipoensis treated with M. anisopliae var. anisopliae on the third day after inoculation were: control, 15.7%; dose A 95.7% and dose B 100%; for M. anisopliae var. acridum: control, 13.3%; dose A 66.4% and dose B 88,8%. The average of conidia production was higher for M. anisopliae var. anisopliae than M.anisopliae var. acridum. The results showed that M. anisopliae var. anisopliae presented better potential for the biological control of N. coxipoensis.