Chrysoperla externa (Neuroptera: Chrysopidae) es uno de los enemigos naturales del pulgón de la hoja del maíz Rhopalosiphum maidis (Hemiptera: Aphididae) y tiene potencial aplicación en el control biológico contra esta plaga. Fue investigado el efecto de la temperatura sobre el desarrollo y capacidad depredadora de C. externa alimentada con ninfas de R. maidis. Huevos frescos del crisópido fueron mantenidos a 15, 20, 25 ó 30 °C bajo una humedad relativa de 70% y 12 h fotofase. Fueron evaluadas la duración del período embrionario, la duración y viabilidad de la fase larvaria (primer, segundo y tercer estadio), fases de prepupa, pupa y adulta del depredador. La duración de todas las etapas del desarrollo se redujo al aumentar la temperatura, mientras que la viabilidad de todas las fases alcanzó el 100 % a los 20 y 25 °C. El umbral de temperatura y el valor de la constante térmica K obtenidos para el ciclo de vida completo (de huevo a adulto) fueron 10,7 ºC y 377,8 grados-día, respectivamente. Independiente de la temperatura, el consumo de ninfas de R. maidis por C. externa aumentó con el desarrollo de las larvas. A los 20 y 25 °C, el número promedio de pulgones consumidos durante toda la fase larvaria alcanzó aproximadamente 350 especímenes. Se concluye que el desarrollo de las formas inmaduras de C. externa alimentada con R. maidis, así como la viabilidad y su capacidad depredadora, se favorecen a temperaturas entre 20 y 25 °C.

Chrysoperla externa (Neuroptera: Chrysopidae) is one of the natural enemies of the corn leaf aphid Rhopalosiphum maidis (Hemiptera: Aphididae) and has potential application in the biological control of that pest. The effect of' temperature on the development and the predatory capacity of this chrysopid fed with R. maidis nymphs was investigated. Fresh eggs of C. externa were maintained at 15, 20, 25 or 30 °C under 70% relative humidity and 12 h photophase, and the duration of the embryonic stage, as well as the duration and viability of the larval (first, second and third instars), prepupal, pupal and adult forms of the predator were evaluated. The duration of each of these stages decreased with increasing temperature, whilst the viabilities of all forms attained 100% at 20 and 25 °C. The threshold temperature and the value of the thermal constant K obtained for the complete life cycle (egg to adult) were, respectively, 10.7 °C and 377.8 degree-days. Independent of temperature, the consumption of R. maidis nymphs by C. externa increased as the larvae reached maturity. At 20 and 25 °C the average number of aphids consumed during the complete larval stage was maximal at approximately 350 specimens. It is concluded, therefore, that the development of the immature forms of C. externa fed on R. maidis as well as its viability and predatory capacity, were favored at temperatures between 20 and 25 °C.

Este estudio tuvo como objetivo caracterizar los Hemerobiidae (Neuroptera) asociados al "Cerrado" sensu stricto y bosque de galería, en el estado de Minas Gerais, Brasil. El muestro de hemeróbidos se realizó quincenalmente con auxilio de trampas Malaise entre noviembre de 2003 y octubre de 2004. En las dos áreas de estudio se capturaron 181 ejemplares de hemeróbidos de cinco especies. Las especies: Nusalala tessellata, Megalomus impudicus, Hemerobius bolivari y Notiobiella sp., se encontraron en ambos sitios; la quinta especie Sympherobius sp. se encontró únicamente en Pedra do Indaiá. La diversidad de especies (índice de Shannon-Wiener) y la equitatividad (J) de Hemerobiidae fueron similares para las áreas Cerrado sensu stricto y bosque de galería (H' = 0,47 - 0,49 y J = 0,78 - 0,69) y las diferencias observadas entre los sitios de colecta no fueron significativas.

This study aimed to identify the Hemerobiidae (Neuroptera) associated to Brazilian savannah and gallery forest, in Minas Gerais State, Brazil. The sampling was carried every two weeks at Brazilian savannah (Cerrado) in Divinópolis and at gallery forest in Pedra do Indaiá, both in Minas Gerais State, Brazil. Collecting was carried out between November 2003 and October 2004, with Malaise traps. A total of 181 specimens of five species of Hemerobiidae were collected. The species Nusalala tessellata, Megalomus impudicus, Hemerobius bolivari and Notiobiella sp. were collected in the two sites; the fifth species Sympherobius sp. was found only in Pedra do Indaiá. The species of diversity (index of Shannon-Wiener) and the equitability (J) of Hemerobiidae were similar in the areas of Brazilian savannah and gallery forest (H' = 0.47 - 0.49, respectively, and J = 0.78 - 0.69, respectively), and the differences observed between the two locations were not significant.

O objetivo deste trabalho foi verificar as espécies de flebotomíneos capturadas com armadilha Malaise nos municípios de Divinópolis e Pedra do Indaiá, localizados em Minas Gerais. As coletas foram realizadas de novembro de 2003 a outubro de 2004. Trinta e dois exemplares foram capturados, pertencentes a sete espécies: Pintomyia monticola (Costa Lima), Nyssomyia whitmani (Antunes & Coutinho), Pintomyia christenseni (Young & Duncan), Evandromyia cortelezzii (Brèthes), Sciopemyia sordellii (Shannon & Del Ponte), Pintomyia pessoai (Coutinho & Barretto) e Psathyromyia aragaoi (Costa Lima).

The aim of this paper was to verify the sand fly species collected with Malaise trap in the cities of Divinópolis and Pedra do Indaiá, both located in Minas Gerais state. Collections were carried out between November 2003 and October 2004. Thirty two specimens were captured belonging to seven species: Pintomyia monticola (Costa Lima), Nyssomyia whitmani (Antunes & Coutinho), Pintomyia christenseni (Young & Duncan), Evandromyia cortelezzii (Brèthes), Sciopemyia sordellii (Shannon & Del Ponte), Pintomyia pessoai (Coutinho & Barretto) and Psathyromyia aragaoi (Costa Lima).

Estudou-se a resposta funcional de Chrysoperla externa (Hagen) alimentada com cinco densidades de Schizaphis graminum (Rondani). O delineamento experimental foi inteiramente casualizado, com cinco tratamentos e dez repetições. Os ensaios foram conduzidos em câmaras climáticas a 25 ± 1ºC, UR de 70 ± 10 % e fotofase de 12 horas. Observou-se para os três ínstares um maior consumo em função do aumento na densidade de presas oferecidas; porém, houve uma tendência de estabilização no consumo a partir da densidade média de presas pré-estabelecida, exceto para o primeiro ínstar, que apresentou um aumento constante no consumo de pulgões. A duração do primeiro e terceiro ínstares, e da fase de larva como um todo, aumentou em função do aumento na disponibilidade de presas oferecidas. Entretanto, no segundo ínstar, a duração diminuiu em função desse aumento. Os resultados evidenciaram para o 1°, 2° e 3° ínstares e toda a fase de larva uma resposta funcional do Tipo II. Para a densidade média de presas oferecida foi avaliado o tempo de busca e manuseio. O menor tempo de busca foi verificado para larvas de segundo ínstar, enquanto que o primeiro ínstar apresentou o maior tempo de busca e de manuseio. O tempo de manuseio diminuiu progressivamente com o desenvolvimento da larva.

The functional response of Chrysoperla externa (Hagen) fed on Schizaphis graminum (Rondani) was studied under five densities of prey. The experimental design was completely randomized with five treatments and ten replications. The tests were conducted in growth chambers at 25 ± 1ºC, RH of 70 ± 10% and photophase of 12 hours. Consumption increased in function of prey density in all instars. However, consumption tended to stabilize when a pre established average density of prey was offered, except for the first instar, which showed a constant increase in aphid consumption. The duration of the first and third instars and of the larval phase, as a whole, increased in function of the increased availability of prey. The duration of the second instar, however, decreased in function of increased prey availability. The results for the 1st, 2nd and 3rd instars and the larval phase showed a Type II functional response. Handling and searching time was evaluated for the average density of offered prey. The lowest searching time was verified for second instar larvae while the first instar showed the highest searching and handling time. Handling time dimi-nished progressively with larvae development.