Resumen El control biológico en caña de azúcar en Venezuela se ha logrado establecer como una medida única, con resultados óptimos del uso de parasitoides y entomopatógenos para el control de los taladradores del género Diatraea, y, posteriormente, de la candelilla Aeneolamia spp., ambas plagas claves del cultivo. Para los taladradores, se logró después de liberaciones sistemáticas de la mosca amazónica Lydella minense desde un inicio, a mediados del siglo XX y luego con el establecimiento de la avispa bracónida Cotesia flavipes, a partir de 1987. Para el control biológico de Aeneolamia varia, plaga que implicaba la aplicación frecuente de insecticidas, después de la introducción del uso del hongo entomopatógeno Metarhizium anisopliae desde 1977, se ha establecido como medida eficiente para el control de sus adultos, aunque las ninfas eran menos controladas. Este aspecto se resolvió mediante la introducción del nematodo entomopatógeno Heterorhabditis bacteriophora en 2004, el cual se viene utilizando en forma general, y prácticamente ya se tienen las medidas biológicas para evitar la aplicación de insecticidas. Como ejemplo se tiene a la Azucarera Río Turbio, aunque en las últimas zafras ha tenido una reducción en sus áreas, por diferentes factores. Durante los últimos 58 años, la infestación de Diatraea muestra una reducción de 15 a 3.18 %, con lo cual se salvan 170 552.62 toneladas métricas (TM), con un valor de US$ 49 196 045 y un costo del control biológico de US$ 1 187 189 lo que se traduce en un beneficio-costo de US$ 41.44. Antes del establecimiento del control biológico, Aeneolamia se controlaba exclusivamente con insecticidas químicos, aplicados al follaje para los adultos y al suelo para las ninfas. Simultáneamente desde entonces, se ha utilizado el hongo M. anisopliae producido por empresas nacionales, hasta cubrir 87 000 ha, entre 1986 y 1990. También, desde 2004 se inició la utilización de nematodos entomopatógenos para el control de ninfas de Aeneolamia.

Abstract The biological control in sugarcane in Venezuela has been established as a unique measure, having optimal results of the use of parasitoids and entomopathogens for the control of borers of the genus Diatraea, and later of the candelilla Aeneolamia spp., both key pests of the crop. For borers it was achieved after systematic releases of the Amazonian fly Lydella minense from the middle of the last century and then with the establishment of the braconid wasp Cotesia flavipes from 1987. For the biological control of Aenolamia varia, pest that involved the frequent application of insecticides, after the introduction of the use of the entomopathogenic fungus Metarhizium anisopliae since 1977, has been established as an efficient measure for the control of its adults, however, the nymphs were less controlled. This aspect was resolved through the introduction of the entomopathogenic nematode Heterorhabditis bacteriophora in 2004, which has been widely used as a biological measure to avoid the application of insecticides. As an example, we have the Azucarera Río Turbio, although in the last harvests it has had a reduction in its areas due to different factors. During the last 58 years, Diatraea infestation shows a reduction of 15 to 3.18 %, which saves 170 552.62 metric tons with a value of US$ 49 196 045 and a cost of biological control of US$ 1 187 189 which translates into a benefit-cost of US$ 41.44. Before the establishment of biological control, Aeneolamia was controlled exclusively with chemical insecticides applied to foliage for adults and soil for nymphs. Simultaneously since then, the entomopathogenic fungus M. anisopliae produced by national companies has been used and this entomopathogen was used on 87 000 hectares between 1986 and 1990. Also since 2004, the methodology of using entomopathogenic nematodes to control Aeneolamia nymphs began.

Resumen Servicio Biológico, SERVBIO, empresa situada en el valle del Turbio, estado Lara, Venezuela, fundada por el autor entre 1977 a 2008, se dedicó a la producción de controladores biológicos y su uso en la agricultura venezolana, iniciándose en el control de los taladradores de la caña de azúcar del género Diatraea, con la mosca amazónica, Lydella (=Metagonistylum) minense (Diptera: Tachinidae), la cual se utilizó exclusivamente hasta el año 1988. Después de seis años de haber realizado liberaciones en todo el territorio, Cotesia flavipes (Hymenoptera: Braconidae) se estableció en 1987 en Ureña (estado Táchira) y Cariaco (estado Sucre), por lo que se inició en 1988 su producción masiva. Entre 1962 y 2011, se disminuyeron los porcentajes de intensidad de infestación de 15 % hasta 1.68 % en el área de la Azucarera río Turbio y se tuvo un beneficio: costo del control biológico de 41.25 a 1. SERVBIO incursionó en la producción de diferentes controladores biológicos; en particular, desarrolló técnicas de producción, y su aplicación en los programas de manejo integrado de plagas (MIP). La introducción de Telenomus remus (Hymenoptera: Braconidae), parasitoide de Spodoptera frugiperda (Lepidoptera: Noctuidae), desde un inicio, mostró efectividad con resultados, de alto parasitismo, y ahorro del uso de plaguicidas. T. remus es utilizado en la actualidad en los programas de MIP del maíz y otras gramíneas. También SERVBIO experimentó la utilización del nematodo Heterorhabditis bacteriophora para el control de la candelilla o salivazo de la caña de azúcar, Aenolamia varia, lográndose 80 % de control en una hacienda en Turen (estado Portuguesa); por lo cual es adoptado actualmente para el MIP de la caña de azúcar. Por lo tanto, para las plagas clave de este cultivo, se cuenta con controladores biológicos eficientes. SERVBIO ha sido una empresa que ha prestado una labor educacional, que conduce trabajos de investigación y pasantías profesionales, tesis de grado, y prácticas para estudiantes de pregrado y posgrado. También ha prestado asesorías para instalación de laboratorios.

Abstract Servicio Biológico (SERVBIO), a company located in the Turbio valley, state of Lara, Venezuela and founded by the author between 1977 and 2008, was dedicated to the production of biological controllers and their use in Venezuelan agriculture. SERVBIO began controlling sugarcane borers of the genus Diatraea, with the amazonian fly, Lydella (=Metagonistylum) minense (Diptera: Tachinidae), which was used exclusively up to 1988. After six years of country-wide releases, Cotesia flavipes (Hymenoptera: Braconidae) was established in 1987 in two locations: Ureña (state of Táchira) and Cariaco (state of Sucre), with its massive production starting in 1988. From 1962 to 2011, infestation intensity percentages were reduced from 15 % to 1.68 % in the area of the Rio Turbio Sugar Factory, showing the cost-benefit of biological control from 41.25 to 1. SERVBIO ventured in the production of different biological controllers, especially developing production techniques and applying them to integrated pest management (IPM) programs. The introduction of Telenomus remus (Hymenoptera: Braconidae), a parasitoid of Spodoptera frugiperda (Lepidoptera: Noctuidae), showed since the beginning effectiveness with high parasitism results and savings in the use of pesticides. T. remus is currently used in IPM programs for corn and other grasses. SERVBIO also experimented with the use of the nematode Heterorhabditis bacteriophora to control the “candelilla” or sugarcane spittlebug, Aeneolamia varia, achieving 80 % of control in a farm in Turen (state of Portuguesa); consequently, it is currently implemented in sugarcane IPM. Therefore, efficient biological controllers are used for the key pests of this crop (Diatraea spp. and A. varia). SERVBIO provides educational services, conducts research projects, and offers professional internships, graduate thesis, and internships for undergraduate and graduate students. SERVBIO has also provided advisory services on the installation of laboratories.

Several aspects of the biology and behavior of a Cotesia flavipes line from Costa Rica, and its host Diatraea saccharalis were studied in Piura, Peru. This research was conducted in the Centro de Producción de Insectos Útiles (CPIU) of the Caña Brava Enterprise, at an average temperature of 28 °C and 60% humidity. The life cycle of Cotesia flavipes lasts 15 days; the larval period of the first, second and third stages are 3.3; 2.5 and 1.3 days respectively. Pupa lasts 5.6 days and sex ratio (M:F) is 1:3.9. Adult longevity is greater when it is fed. The pre-oviposition period and oviposition times are 37.9 minutes and 6.1 seconds, respectively. C. flavipes females parasitize 1 to 2 larvae. The adult emergency percentage is 91.2%. There are no differences in the number of age-parasitized larvae of Cotesia flavipes C. on stages IV, V and VI of Diatraea saccharalis F. Cotesia flavipes presents polygamous mating, sexual reproduction and parthenogenic reproduction of arrenotochia type. The male copulates from 5-14 females, the pre-mating ranges from 1-94 minutes and the mating time ranges from 8-21 seconds.

En Piura, Perú, se estudiaron algunos aspectos de la biología y comportamiento de una línea de Cotesia flavipes, procedente de Costa Rica, en larvas de Diatraea saccharalis. El estudio en tres generaciones se realizó en el laboratorio del Centro de Producción de Insectos Útiles (CPIU) de la Empresa Caña Brava, a una temperatura promedio de 28 °C y 60% de humedad relativa (HR). Se determinó el ciclo de desarrollo del parasitoide en 15 días: periodo incubación, 2.5 días; estadio larval I, II y III de 3.3; 2.5 y 1.3 días respectivamente; periodo pupal, 5.6 días; proporción de sexos 1:3.9 macho/hembra; periodo de pre-oviposición 37.9 minutos y tiempo de oviposición, 6.1 segundos. La longevidad del adulto es mayor con alimento. El porcentaje de emergencia es de 91.2% y la hembra parasita 1 a 2 larvas. El apareamiento es polígamo, con reproducción sexual y partenogénica tipo arrenotoquia. El macho copula con 5-14 hembras, el pre-apareamiento oscila entre 1-94 minutos y el tiempo de cópula entre 8-21 segundos. No hay diferencias en el número de larvas parasitadas en los estadios IV, V y VI de D. saccharalis.

Resumen En el valle del río Cauca se ha incrementado el daño por parte de los barrenadores del tallo, Diatraea spp., en la caña de azúcar, debido a dos nuevas especies, D. tabernella y D. busckella, que se sumaron a las ya conocidas D. saccharalis y D. indigenella. Se estudió la bioecología de la plaga y de sus enemigos naturales para ajustar los planes de manejo, que consisten principalmente en control biológico. Se realizó el seguimiento de la plaga en un ciclo de cultivo, en nueve campos distribuidos por todo el valle del río Cauca. El muestreo se hizo mediante una cuadrícula de 30x30 metros y 50 puntos georreferenciados en cada campo. Se registró el número de tallos afectados y del número de entrenudos barrenados por tallo. En el exterior de la cuadrícula se recolectaron huevos y larvas de la plaga mediante un esfuerzo de muestreo de una hora-hombre. La zona norte presentó los mayores niveles de daño y el predominio de D. tabernella y D. busckella. Los parasitismos de huevo por Trichogramma exiguum llegaron hasta el 98 % y Cotesia flavipes fue el parasitoide de larvas más abundante. Hubo correlaciones positivas entre el porcentaje de tallos con daño (%TD) y la edad de la caña, y entre el número de larvas y las larvas parasitadas. El análisis espacial del %TD evidenció una distribución agregada, concentrándose en los bordes de la cuadrícula de muestreo. El esquema de manejo debe considerar liberaciones de insectos benéficos en las etapas avanzadas del cultivo y dirigido a los focos de infestación.

Abstract Sugarcane stem borer (Diatraea spp.) damage has increased in the Cauca River Valley (CRV) due to two new species, D. tabernella and D. busckella, which joined the two already known species, D. saccharalis and D. indigenella. A study of the bioecology of these pests and their natural enemies is presented in order to increase the effectiveness of pest management, which consists primarily of biological control. An assessment of the extent of pest damage was completed during a crop cycle in nine fields distributed along the CRV. Sampling was done in a 30x30 meter grid and 50 points were geo-referenced in each field. A registry was made of the number of damaged stalks and the number of bored internodes per stalk. Outside the grid, eggs and larvae of the pests were collected by means of a one man-hour sampling effort. The northern CRV showed the greatest levels of pest injury and a predominance of D. tabernella and D. busckella. Egg parasitism by Trichogramma exiguum reached levels of 98 %, whereas Cotesia flavipes was the most abundant larval parasitoid. There were positive correlations between the percent of damaged stalks (%TD) and crop age, and between the number of larvae and parasitized larvae. A spatial analysis of %TD showed an aggregated distribution concentrated toward the edge of the grid. Pest management protocols should be differentiated by region within the CRV in order to prioritize areas of greatest infestation.

Diatraea busckella es considerada la plaga más limitante del cultivo de caña panelera en el municipio de Supia (Colombia), causando grandes pérdidas en la producción. El objetivo del trabajo fue evaluar el efecto de los parasitoides Trichogramma exiguum, lydella minense, Billaea claripalpis, Cotesia flavipes, del hongo B. bassiana y la bacteria B. thuringiensis var. Kurstaki para el control de esta plaga. En las parcelas donde se realizó la liberación y aplicación de los enemigos naturales se encontró una intensidad de infestación de la plaga de 0,57 %, mientras que en la parcela testigo fue de 4,17 %. Los biocontroladores utilizados se presentan como alternativa para el control de la plaga.

Diatraea busckella is considered the most limiting pest in sugarcane crops in the Municipality of Supia, Colombia, generating great losses in production. The aim of this study was to evaluate the effect of parasitoids Trichogramma exiguum, Lydella minense, Billaea claripalpis, Cotesia flavipes, fungi and B. bassiana and the bacteria B. thuringiensis kurstaki variety for the control of this pest. An intensity of pest infestation of 0.57% was found in the plots where the release and application of the natural enemies was carried out, while in the control plot the infestation was 4.17%. The bio-controllers used are presented as an alternative for pest control.

A presente pesquisa visou elucidar quais aspectos da resposta imune em Diatraea flavipennella são suprimidos pelo parasitoide Cotesia flavipes, para garantir o sucesso do parasitismo. Investigou-se a presença de células em apoptose no corpo gorduroso pela técnica de TUNEL. De acordo com os resultados verificou-se redução nos níveis de oxido nítrico e na atividade da fenoloxidase nas lagartas parasitadas, aos três dias, e redução do número total de hemócitos aos três e sete dias. Na contagem diferencial, observou-se aumento no número de plasmatócitos e redução de esferulócitos, no terceiro dia de parasitismo. O número de micro-esferas melanizadas, nas lagartas parasitadas, foi inferior mostrando uma melanização menos intensa. A análise ultra-estrutural comfirmou o efeito imunossupressor de C. flavipes para suprimir a resposta de encapsulação em D. flavipennella, pois, somente foi evidenciado à formação de cápsula de hemócitos, aderidas à superfície das micro-esferas, nas lagartas não parasitadas. Como efeito do parasitismo, foi registrado ainda no terceiro dia presença de hemócitos e células do corpo gorduroso em apoptose, além deste último apresentar aspecto de degeneração. Conclui-se que C. flavipes suprimi a resposta imunológica celular e humoral de D. flavipennella e afeta drasticamente o tecido gorduroso.

The present research aimed to elucidate which aspects of immune responses in Diatraea flavipennella are suppressed by the parasitoid Cotesia flavipes, thus, ensuring parasitism success. We investigated the presence of apoptosis in fat body cells through the TUNEL technique. According to the results, reduced levels of nitric oxide and phenoloxidase activity were observed in larvae parasitized for three days, and reduced total number of hemocytes, after three and seven days. An increase in plasmatocytes and decrease in spherulocytes numbers were observed in the differential count on the third day of parasitism. The number of melanized microspheres in parasitized larvae was low and indicated less intense melanization. The ultrastructural analysis confirmed the immunosuppressive effect of C. flavipes on the encapsulation response of D. flavipennella because only the formation of hemocytes capsules, adhered to the microspheres' surface, was evidenced in non-parasitized caterpillars. The effect of parasitism was also recorded on the third day with the presence of hemocytes and apoptosis in fat body cells, including aspects of degeneration in the latter. We concluded that C. flavipes suppresses cellular and humoral immunological responses in D. flavipennella and drastically affects the host's fat tissue.

O objetivo desta pesquisa foi avaliar a preferência do parasitoide Cotesia flavipes (Hymenoptera: Braconidae) por lagartas de Diatraea saccharalis (Lepidoptera: Crambidae), alimentadas com diferentes cultivares de cana-de-açúcar. O experimento foi conduzido em laboratório, em duas condições de alimentação, uma envolvendo lagartas de D. saccharalis, alimentadas em dieta artificial, e, a outra, com lagartas alimentadas em dieta artificial e mantidas temporariamente nos toletes dos cultivares de cana-de-açúcar. Os cultivares utilizados foram: SP80-1842 e SP81-3250, resistentes, e RB855536, suscetível à D. saccharalis. A preferência para oviposição das fêmeas de C. flavipes foi avaliada em testes com e sem chance de escolha, em delineamento inteiramente casualizado, com quatro tratamentos e 15 repetições. Lagartas de D. saccharalis com 19 dias de idade foram oferecidas para fêmeas de C. flavipes, acasaladas e com 24 horas de idade, em ambos os testes. No teste com chance de escolha, utilizou-se um olfatômetro, o qual constou de quatro compartimentos, em cujo centro liberaram-se quatro fêmeas de C. flavipes, enquanto, no teste sem chance de escolha, foram utilizadas placas de Petri, no interior das quais se colocou uma lagarta de D. saccharalis, oriunda das duas condições de alimentação. Nestes testes, foi observada a percentagem de parasitismo e, continua-mente, o comportamento da primeira escolha de fêmeas de C. flavipes, em intervalos de zero a um, um a três, três a cinco, cinco a oito e de oito a dez minutos após as liberações. Lagartas de D. saccharalis, oriundas da alimentação em dieta artificial com colmos triturados dos cultivares, foram igualmente preferidas para atratividade de fêmeas do parasitoide C. flavipes. A percentagem de parasitismo de lagartas de D. saccharalis, criadas com dietas artificiais com colmos dos cultivares SP80-1042 e RB855536, foi igualmente parasitadas por C. flavipes.

The objective of this study was to evaluate the preference of the parasitoid C. flavipes (Hymenoptera: Braconidae) for larvae of Diatraea saccharalis (Lepidoptera: Crambidae) fed on different sugarcane cultivars. The experiments were conducted in laboratory with two feeding conditions: larvae of D. saccharalis fed on artificial diet and larvae fed on artificial diet and kept temporarily on cane setts of the different cultivars. The resistant cultivars SP80-1842 and SP81-3250and the susceptible RB855536 cultivar to D. saccharalis were used in the experiment. The oviposition preference of C. flavipes females was evaluated in free-choice and no-choice tests, in a completely randomized design with four treatments and 15 replications. Larvae of D. saccharalis with 19 days of age were fed to mated females of C. flavipes with 24 hours of age in both tests.. For the free-choice test was used an olfactometer of four compartments, in which four females of C. flavipes were released in its center. For the no-choise test was used Petri dishes, each one with one larva of D. saccharalis treated under both feeding conditions. In these tests, it was determined the percentage of parasitism and continuously observed the behavior of the first choice of C. flavipes females at intervals of zero to one; one to three, three to five, five to eight and eight to ten minutes. Larvae of D. saccharalis reared in artificial diet with powdered stems of the cultivars were equaly preferred by females of the parasitoid C. flavipes; The percentage of parasitism of D. saccharalis larvae reared on artificial diets with powdered stems of the cultivars SP80-1042 and RB855536 were equaly parasitized by C. flavipes.

Diatraea saccharalis Fabr. (Lepidoptera: Crambidae) é uma das principais pragas da cana-de-açúcar no Brasil. O manejo de áreas infestadas é baseado na liberação de Cotesia flavipes (Cameron) (Hymenoptera: Braconidae), um parasitoide de larvas de D. saccharalis, mas existem dúvidas a respeito da eficiência de C. flavipes, principalmente em relação à sua capacidade de dispersão em campo. Assim, o objetivo deste estudo foi avaliar a capacidade de dispersão de C. flavipes em canaviais e sugerir um método de liberação que propicie maior eficiência do parasitoide. O estudo foi conduzido em quatro áreas de aproximadamente 1 ha, e, em cada uma, pedaços de colmos contendo 20 larvas de D. saccharalis foram distribuídos em grid retangular e 12 mil adultos de C. flavipes foram liberados em quatro pontos, separados entre si por 50 m e a 25 m das bordaduras do campo. Três dias depois, as larvas de D. saccharalis foram removidas e mantidas em laboratório até se transformarem em pupas ou até a emergência de C. flavipes. O parasitismo variou de 13,2% a 42,8%. As larvas parasitadas se distribuíram ao acaso em uma área e em três áreas a distribuição foi agregada, com alcance de 15 a 25 m. Visto que o sucesso do parasitismo está diretamente ligado à dispersão do parasitoide, sugere-se que os pontos de liberação estejam distantes entre si 30 m, visto que o raio de dispersão pode ser de 15 m.

Diatraea saccharalis Fabr. (Lepidoptera: Crambidae) is a major sugarcane pest in Brazil. The management of infested areas is based on the release of Cotesia flavipes (Cameron) (Hymenoptera: Braconidae), a parasitoid of D. saccharalis larvae, but there are doubts about the effectiveness of C. flavipes, primarily regarding its rate of dispersal in sugarcane fields. Thus, the objective of this study was to evaluate the dispersal of C. flavipes in a sugarcane field and suggest a release method that provides higher parasitoid efficiency. The study was carried out in four areas of approximately 1 ha, in which stalk pieces containing 20 D. saccharalis larvae were distributed in a rectangular grid, and 12,000 C. flavipes adults were released at four points, that were 50 m apart and 25 m from the field border. Three days later, the D. saccharalis larvae were recovered and kept in the laboratory until they reached pupal stage or C. flavipes emergence. Parasitism varied from 13.2% to 42.8%. The random distribution of parasitized larvae was found in one assay. In three areas, the parasitized larvae showed an aggregated distribution, with a range of 15 to 25 m. Since the parasite's success is directly linked to parasitoid dispersion, it would be interesting to move the release points to 30 m from each other because the dispersal may happen in a 15 m radius.

The augmentative biological control of Diatraea saccharlis Fabricius (Lepidoptera: Crambidae) requires the mass rearing of the parasitoid Cotesia flavipes Cameron (Braconidae: Microgastrinae), and for this, it's necessary the development of efficient artificial diets. The goal was to examine the effects of different diet types on biological parameters of D. saccharalis and their impact on coccon production of C. flavipes. 46136 eggs of D. saccharalis were sow on eleven combinations of artificial diets, with two types of flours and three types of antibiotics. The results showed that the diet composition affected biological parameters of both species. The larger efficiency in the rearing was obtained with the use of combinations of bean flour and ampicillin. However, if we consider the relationship between production costs and biological parameters, the diet with bean flour, oxytetracycline and streptomycin was the most adequate for mass rearing.

El control biológico aumentativo de Diatraea saccharalis Fabricius (Lepidoptera: Crambidae) requiere la cría masiva del parasitoide Cotesia flavipes Cameron (Braconidae: Microgastrinae) y por ello, es necesario el desarrollo de dietas artificiales eficientes. El objetivo fue examinar los efectos de distintos tipos de dieta sobre parámetros biológicos de D. saccharalis y su impacto en la producción de cocones de C. flavipes. Se sembraron 46136 huevos de D. saccharalis en once combinaciones de dietas artificiales, con dos tipos de harinas y tres tipos de antibióticos. Los resultados mostraron que la composición de la dieta afectó los parámetros biológicos de ambas especies. La mayor eficiencia en la cría se obtuvo con el empleo de combinaciones de harina de poroto y ampicilina. Sin embargo, si se considera la relación entre costos de producción y parámetros biológicos, la dieta con harina de poroto, oxitetraciclina y estreptomicina resulta más adecuada para la cría masiva.

A broca da cana-de-açúcar Diatraea flavipennella (Box.) (Lepidoptera: Crambidae), tem predominado nos canaviais nordestinos apesar de constantes liberações do parasitoide larval Cotesia flavipes (Cam.) (Hymenoptera: Braconidae). Apesar de ser utilizado no controle das brocas Diatraea spp. a sua eficiência de controle sobre D. flavipennella tem sido questionada. Objetivando elucidar esse problema, foram conduzidos testes de preferência, utilizando-se fêmeas de C. flavipes com 24h de idade, acasaladas e alimentadas oferecendo-se lagartas de Diatraea saccharalis (Fabr.) (Lepidoptera: Crambidae) e D. flavipennella. As fêmeas de C. flavipes foram criadas em uma das brocas, sendo testadas individualmente e tendo como hospedeiros lagartas de uma das espécies de Diatraea, ou ambas as espécies. No primeiro experimento, as fêmeas foram liberadas por 10 minutos em arena experimental utilizando apenas pistas olfativas, ou seja, as fêmeas não tinham contato direto com o hospedeiro. No segundo experimento, as fêmeas foram liberadas por 30 min. em uma arena que permite o contato direto das vespas com o hospedeiro, sendo liberadas individualmente na arena com larvas de D. saccharalis e D. flavipennella, simultaneamente. Os resultados dos testes mostraram que as vespas não tiveram preferência entre os dois hospedeiros. Assim, conclui-se que C. flavipes é capaz de localizar as duas espécies de Diatraea.

The sugarcane borer Diatraea flavipennella (Box.) (Lepidoptera: Crambidae), has ultimately predominated in the sugarcane fields of the Brazilian northeast region, despite the continual release of the parasitoid Cotesia flavipes (Cam.) (Hymenoptera: Braconidae). Questions have been raised about the efficiency of Diatraea spp. in controlling D. flavipennella. In this study, females reared in one of the borers were tested individually and as hosts with the larvae of either of the Diatraea species alone or the larvae of both species. In the first experiment, the females were released for 10 min within the experimental arena using only olfactory cues. In the second experiment, C. flavipes females were individually released for 30 min. within the arena, allowing direct contact with its host, either D. saccharalis or D. flavipennella, or both host species at the same time. The wasps showed no preference for either one of the hosts, thus being able to locate borers in general.

O objetivo do trabalho foi avaliar diferentes dietas para lagartas de Diatraea saccharalis, com o intuito de obter informações sobre as características biológicas da praga e consequentemente avaliar a qualidade do parasitoide Cotesia flavipes, visando melhorar tecnicamente sua produção massal. Lagartas de 24 horas de idade foram transferidas para tubos (25 lagartas/tubo) contendo dieta artificial com levedura de cerveja e germe de trigo e outra somente com germe de trigo como fonte de proteína. Depois de aproximadamente 15 dias, as lagartas foram retiradas dos tubos e acondicionadas em placas com dieta, sendo observadas lagartas de D. saccharalis não parasitadas e parasitadas para avaliação das características biológicas de D. saccharalis e C. flavipes.nas diferentes dietas. Além da observação das características biológicas de D. saccharalis, foram realizadas medições nas lagartas de 15 dias de idade. Também, massas de pupas de C. flavipes.produzidas em biofábrica foram classificadas em três diferentes tamanhos, sendo pequenas (1,3 a 2,5 cm de comprimento), médias (2,5 a 3,5 cm de comprimento) e grandes (3,5 a 4,0 cm de comprimento). Após a emergência dos adultos foi realizado o parasitismo em lagartas de D. saccharalis, sendo observados o número de machos e fêmeas, tamanho da massa, razão sexual e número de pupas inviáveis. A dieta artificial que contém somente germe de trigo é a mais indicada para criação massal do hospedeiro D. saccharalis para produção em larga escala de C. flavipes. Massas de pupas classificadas como grandes possuem melhor qualidade em criações massais de C. flavipes.

The aim of this work was to evaluate different diets for Diatraea saccharalis larvae, obtaining information about the biological characteristics of the pest, and to evaluate the quality of Cotesia flavipes parasitoid, to improve mass rearing method. For the accomplishment of the experiment, 24 hour-old larvae were transferred to tubes (25 larvae/tube) containing artificial diets with yeast and wheat germ or just wheat germ as protein source. After approximately 15 days, the larvae were removed from tubes and placed in Petri dishes, being observed D. saccharalis larvae not parasitized and parasitized for evaluation of D. saccharalis and C. flavipes.biological characteristics. Biological characteristics of D. saccharalis were also evaluated in 15 day-old larvae. Pupae mass of C. flavipes.from mass rearing were classified in three different sizes separated in small (1.3 to 2.5 cm of length), moderate (2.5 to 3.5 cm of length) and large (3.5 to 4.0 cm of length) classes. After the adult emergency, the parasitism was evaluated in D. saccharalis larvae, being observed the number of males and females, size of pupae mass, sex ratio and number of unviable pupae. The artificial diet that contains wheat germ is the most suitable for D. saccharalis mass rearing and C. flavipes. Pupae mass of large size presents better quality of C. flavipes.

Diatraea saccharalis (Lepidoptera: Crambidae), broca da cana-de-açúcar, tem sido controlada por Cotesia flavipes (Hymenoptera: Braconidae); pouco se sabe sobre o efeito do parasitismo nos diferentes órgãos do inseto hospedeiro, principalmente no intestino médio. O objetivo desse trabalho foi verificar as alterações mitocondriais das diferentes células epiteliais do intestino médio de larvas de D. saccharalis parasitadas por C. flavipes. Fragmentos do intestino médio (regiões anterior e posterior) de larvas de D. saccharalis não-parasitadas e parasitadas foram processados para microscopia eletrônica de transmissão. As mitocôndrias das células epiteliais do intestino médio de larvas parasitadas exibem alterações, especialmente rarefação e vacuolização da matriz, que foram mais pronunciadas nas células epiteliais da região anterior do intestino médio na vigência do parasitismo, em especial nas células colunares.

The sugarcane borer Diatraea saccharalis (Lepidoptera: Crambidae) has been controlled by Cotesia flavipes (Hymenoptera: Braconidae); however, very little is known about the effect of the parasitism in the host organs, including the midgut. This work aims to verify mitochondrial alteration in the different midgut epithelial cells of D. saccharalis parasitized by C. flavipes. Midgut fragments (anterior and posterior region) of both non-parasitized and parasitized larvae were processed for transmission electron microscopy. The mitochondria of midgut epithelial cell in the parasitized larvae exhibit morphological alteration, represented by matrix rarefaction and vacuolisation. These mitochondrial alterations are more pronounced in the anterior midgut region during the parasitism process, mainly in the columnar cell.

Cotesia flavipes (Cameron, 1891) (Hymenoptera) is a gregarious endoparasitoid used in applied biological control against Diatraea saccharalis (Fabricius, 1794) (Lepidoptera). In this study, we characterize the larval external morphology and the number of instars of C. flavipes. Parasitized larvae of D. saccharalis were sampled from the 1st to the 10th day after parasitism and dissected in an anticoagulant buffer for collection of C. flavipes immatures. Immatures were processed for scanning electron microscopy. Larvae of C. flavipes were prepared in NaOH solution and slide mounted to allow for mandible size measurements. Analysis of measurements of the parasitoid larval mandible size indicated that C. flavipes has three instars. Newly hatched larvae are caudate-mandibulate, assuming a hymenopteriform shape later in their development. The anal vesicle began to expand in the first instar and, once expanded, remained unchanged up to the beginning of the third instar. At the third instar, the anal vesicle decreased in volume. Herein we report the development and possible functions of the larval external structures modified during the development of C. flavipes, as for example their role in aiding newly-eclosed larvae to avoid the host immune response and to move within the host. To summarize the morphological changes during parasitoid growth, we should mention that the modifications in the anal vesicle were correlated with the feeding activity, and the maintenance of the anal vesicle indicates that this structure remained functional, probably playing a role in nutrient absorption and host regulation. On the other hand, the mandibles of early stage larvae are probably used to assist the parasitoid larvae during eclosion.

Diatraea saccharalis, the main pest of sugarcane, has been controlled by Cotesia flavipes. Very little is known about the effect of parasitism on the host organs, including the midgut. The Lepidoptera midgut epithelium is composed of columnar, goblet, regenerative, and endocrine cells. Spherites have been described in columnar and regenerative cells of several Lepidoptera species, and presented a lot of functional meaning. We identified spherites in the midgut epithelial cells of non-parasitized D. saccharalis larvae analyzed the effect of parasitism on spherite morphology and distribution along the length of the midgut. Midgut fragments of both non-parasitized and parasitized larvae were processed for transmission electron microscopy. All the midgut epithelial cells showed spherites, but they were not preferentially located in a particular part of the cells. Parasitized larvae had more spherites, mainly in the columnar cells, than non-parasitized larvae. This observation was associated with an ionic imbalance within the insect host. Spherites were more abundant in the anterior midgut region than in other regions, which suggests that this region is involved in ion transport by intracellular and/or paracellular route. The morphological variability of spherites in the cells of parasitized larvae was related to the developmental stages of these structures.

Entre los años 1990-1996, se evaluó la importancia de la mosca amazónica (Melagonystilum minense) y de la avispa (Cotesia flavipes) como controles biológicos de los perforadores de la caña de azúcar (Diatraea saccharalis y Diatraea rosa) en el centro de Venezuela. Durante el período de la zafra, seleccionamos aleatoriamente tallos de caña de azúcar que fueron abiertos para observar el número de perforaciones, hospedadores, proporción de hospedadores parasitados, proporción de hospedadores parasitados por la mosca amazónica o por la avispa. Como consecuencia de las periódicas liberaciones de las moscas y las avispas criadas en el laboratorio, observamos una disminución pronunciada de la abundancia relativa de Diatraea spp., pero no se obtuvo un efecto evidente de utilizar ambos parasitoides. La abundancia de Diatraea spp. en presencia de ambos parasitoides fue similar a la observada durante los 45 años en que se utilizó únicamente M. minense como control biológico. Sin embargo, M. minense probablemente sea el principal control biológico de esta plaga por ser más eficiente en la búsqueda de la misma y por ser un competidor más fuerte que C. flavipes.