Resumen Nasutitermes corniger es una termita arbórea que causa daños económicos en las zonas urbanas, y su control es mediante insecticidas químicos. Una alternativa para el control de insectos es el uso de hongos entomopatógenos y extractos de plantas, o el efecto sinérgico de la asociación de estos. Se examinó la toxicidad de los extractos acuosos e hidroetanólicos de Agave sisalana sobre los aspectos biológicos de los hongos Cordyceps farinosa, C. fumosorosea y C. javanica y la acción de los extractos y su efecto sinérgico sobre N. corniger. Se evaluó el efecto de los extractos sobre hongos por germinación, esporulación y crecimiento micelial de los hongos en medio Sabouraud mediante el estudio de aspectos biológicos bajo condiciones de laboratorio y se examinó el control de N. corniger, por ingestión de extractos y de la asociación extracto y hongo sobre papel de filtro, siendo el porcentaje de mortalidad de soldados y obreras de la termita diaria. En general, los extractos resultaron inofensivos para los hongos a concentraciones de 10, 25, 50, 100 y 200 mg.mL-1. Los extractos demostraron acciones termiticidas a las concentraciones ensayadas, provocando la mortalidad de alrededor del 100% de los trabajadores después del tercer y sexto día (LC50: 0.778 a 0.803 mg.mL-1) y del 100% de los soldados entre el cuarto y séptimo días (LC50: 0.146 a 0.956 mg.mL-1). La asociación de los extractos con C. farinosa ESALQ1355 fue más eficiente para inducir la mortalidad en N. corniger. Estos resultados demostraron la eficiencia in vitro de los extractos de sisal en el control de las termitas de N. corniger, solas o en combinación con hongos, lo que sugiere su potencial utilidad conjunta en el control biológico de plagas de insectos.

Abstract Nasutitermes corniger is an arboreal termite that causes economic damage in urban areas, and its control is for chemical insecticides. An alternative for insect control is the use of entomopathogenic fungi and plant extracts, or the synergistic effect of the association of these. The toxicity of aqueous and hydroethanolic extracts of Agave sisalana on the biological aspects of the fungal Cordyceps farinosa, C. fumosorosea and C. javanica and the action of the extracts and their synergistic effect on N. corniger was examined. The effect of the extracts on fungi was evaluated by germination, sporulation and mycelial growth of fungi in Sabouraud medium through the study of biological aspects under laboratory conditions; and control of N. corniger were examined, by ingestion of extracts and of the association extract plus fungus on filter paper, being the percentage of mortality of soldiers and workers of the termite daily. In general, the extracts were inoffensive to the fungi at concentrations 10, 25, 50, 100 and 200 mg.mL-1. The extracts demonstrated termiticidal actions at concentrations tested, causing the mortalities about 100% of the workers after the third and sixth days (LC50: 0.778 to 0.803 mg.mL-1) and 100% of the soldiers between the fourth and seventh days (LC50:0.146 to 0.956 mg.mL-1). The association of the extracts with C. farinosa ESALQ1355 was more efficient in inducing the mortality in N. corniger. These results demonstrated the efficiency in vitro of the sisal extracts in controlling N. corniger termites, alone or in combination with fungi, suggesting their potential joint usefulness in the biological control of insect pests.

O controle microbiano consiste na utilização racional de patógenos, visando à manutenção da população de insetos em equilíbrio no ambiente. Metarhizium anisopliae é a espécie mais estudada e utilizada no controle biológico de insetos. A variabilidade genética dos fungos entomopatogênicos pode ser considerada uma das principais vantagens no controle microbiano de insetos e pode ser detectada por meio de marcadores moleculares, como ITS-RFLP, ISSR e ISSP. Esses marcadores são usados para a caracterização inter e intraespecífica de Metarhizium e outros fungos entomopatogênicos e poderão auxiliar na compreensão da diversidade genética e da estrutura das populações destes fungos. A persistência de M. anisopliae no solo e seu possível efeito na estrutura da comunidade microbiana deste solo são características importantes e pouco estudadas, que devem ser consideradas no processo de seleção de isolados para o controle biológico de insetos.

Microbial control of insects is based on the rational use of pathogens to maintain environmentally balanced pest population levels, and Metarhizium anisopliae has been the most studied and most utilized fungal species for that purpose. The natural genetic variability of entomopathogenic fungi is considered one of the principal advantages of microbial insect control. The inter- and intraspecific variability and the genetic diversity and population structures of Metarhizium and other entomopathogenic fungi have been examined using ITS-RFLP, ISSR, and ISSP molecular markers. The persistence of M. anisopliae in the soil and its possible effects on the structures of resident microbial communities must be considered when selecting isolates for biological insect control.

The aim of this work was to evaluate the effect of temperature on the pathogenicity of Beauveria bassiana against Diatraea saccharalis and evaluate the horizontal transmission capacity among the sugarcane borer larvae. The strains were most pathogenic at 26ºC, followed by 32ºC than at 20ºC, with respective mortalities of 100, 50 and 30.3%. The lethal time was also affected by the temperature, with the shortest LT 50 observed at 26ºC (2.2 days) and the longest at 20ºC (16.2 days). The URM2915 strain appeared most effective in all the experiments as having potential for deployment in biological control programs for the sugarcane borer. Results in horizontal transmission of B. bassiana showed that this procedure could also be adopted as control strategy for the sugarcane borer.

A mosca do figo, Zaprionus indianus, vem se disseminando no Brasil e causou nos últimos anos perdas de até 50% na produção de figos. Uma alternativa viável de controle desta mosca pode ser a utilização de fungos entomopatogênicos. Este trabalho foi conduzido em laboratório (27±1°C, UR 70±10% e fotoperíodo de 12h) para avaliar a suscetibilidade dos estágios de larva e adulto de Z. indianus a cinco concentrações (10(8) a 10(4) conídios mL-1) de B. bassiana (URM2915; ESALQ447) e M. anisopliae (URM3349; URM4403). Não houve mortalidade larval e o período de pré-pupa não sofreu alteração em relação ao grupo controle, já o estágio de pupa foi aumentado em até três dias quando se utilizou B. bassiana. A emergência de adultos diminuiu em relação ao grupo controle: 10,6% quando as larvas foram tratadas com a maior concentração de B. bassiana URM2916 e 2,0% com M. anisopliae URM4403. No bioensaio com adultos, a mortalidade máxima atingiu 98,7% com B. bassiana e 100,0% com M. anisopliae. Os menores valores da CL50 foram de 1,09x10(5) conídios mL-1 para B. bassiana URM2916 e de 1,94x10(4) conídios mL-1 para M. anisopliae URM4403. O tempo letal médio (TL50) variou de 4,5 a 6,12 dias. Os resultados demonstraram que ambos os fungos são eficientes e mostram ser promissores agentes biocontroladores da mosca do figo, com destaque para M. anisopliae URM4403.

The "fig fly", Zaprionus indianus, has spread by in Brazil and in recent years and has caused losses of up to 50% in the production of figs. A viable alternative to control this fly may be the use of entomopathogenic fungi such. The present study was developed in laboratory (27±1°C, RH 70±10% and 12h photoperiod), to assess the susceptibility of larval and adult stages of Z. indianus to five concentrations (10(8) to 10(4) conidia mL-1) of B. bassiana (URM2915; ESALQ447) and M. anisopliae (URM3349; URM4403). There was no larval mortality and the pre-pupal period did not change compared with the control group, whereas the pupal stage was increased by up to three days when we used B. bassiana URM2916. The emergence of adults decreased compared to the control group and was 10.6% when the larvae were treated with the highest concentration of B. bassiana URM2916 and 2.0% for M. anisopliae URM4403. In the adult's bioassay, the maximum mortality reached 98.7% with B. bassiana and 100.0% with M. anisopliae. The lowest LC50 values were 1.09x10(5) conidia mL-1 for B. bassiana URM2916 and 1.94x10(4) conidia mL-1 for M. anisopliae URM4403. The medium lethal time (LT50) ranged from 4.5 to 6.12 days. The results showed that both fungi are efficient and promising biocontrol agents of fig fly, mainly M. anisopliae URM4403.

In order to assess the effectiveness of Metarhizium anisopliae var. anisopliae (Metschnikoff) Sorokin isolates in controlling the sugarcane root spittlebug Mahanarva fimbriolata (Stal) (Hemiptera: Cercopidae), nine isolates obtained from a single geographical region were studied. 'Confirmed cumulative' and 'corrected cumulative' spittlebug mortality rates were measured for each of the isolates. Based on the confirmed mortality curve, the isolates URM5946, URM5951 and URM6033 were considered to be potentially the most effective in a biological control program for M. fimbriolata.

Este fungo foi isolado pela primeira vez de lagartas de L. obliqua de uma agregação em plátano (Platanus acerifolia (Aiton) Wild - Platanaceae), em Bento Gonçalves, RS, Brasil. Após isolamento, purificação e caracterização, realizou-se um teste de patogenicidade com lagartas sadias de L. obliqua para corroborar, sua infectividade pelo postulado de Koch. Constatou-se correspondência morfológica e molecular entre o inóculo e o reisolado, comprovando sua patogenicidade a L. obliqua.

It is recorded for the first time the occurrence of the entomopathogenic fungus Isaria javanica (Frieder. & Bally) Samson & Hywell-Jones (Fungi: Sordariomycetes) infecting Lonomia obliqua Walker (Lepidoptera: Saturniidae: Hemileucinae) caterpillars. This fungus was isolated from L. obliqua individuals collected from Platanus acerifolia (Aiton) Wild- Platanaceae in Rio Grande do Sul state, Brazil. After isolation, purification and characterization, fungal conidia were inoculated on healthy L. obliqua caterpillars and from dead caterpillars the fungal isolates were again obtained. New isolates and the original isolate did not differ when compared by morphological and molecular tests.