ABSTRACT: Studies on aggressiveness of parasitoids, as assessed by their parasitism against pests, used in biological-control programs are highly important to select the most suitable species and/or strain to control insect pests. The present study investigated whether the egg parasitoid Trichogramma galloi Zucchi, an efficient control agent for sugarcane borer Diatraea saccharalis (Fabricius) in Brazil, could be replaced by Trichogramma atopovirilia Oatman & Platner, a parasitoid easier to mass-produce, since it has been found parasitizing D. saccharalis eggs in the warmest region of Brazil and Argentina. Three strains of the genus Trichogramma were compared: T. atopovirilia (ATP strain) reared on a factitious host Anagasta kuehniella (Zeller); T. atopovirilia isoline ATP-I, reared on D. saccharalis eggs for six generations; and T. galloi, reared on A. kuehniella eggs. We measured parasitism of each strain for 72 h and for the entire life span, parasitism rate per cluster of D. saccharalis eggs, number of parasitoids emerged (parasitism viability), and parasitoid life span. The results confirmed that T. galloi is the best species for D. saccharalis control, showing higher control potential, since parasitism and emergence rate were higher for this species. Although T. atopovirilia ATP-I performed reliably in all parameters, T. galloi exceeded and was the most indicated for mass-rearing in control programs for sugarcane borer.

A lagarta-enroladeira Bonagota cranaodes (Meyrick) é nativa da América do Sul, sendo importante praga em macieira no Brasil. O controle é realizado exclusivamente com inseticidas, e o controle biológico é pouco explorado, motivo pelo qual há necessidade de conhecer os inimigos naturais da lagarta-enroladeira. O objetivo deste trabalho foi verificar a ocorrência de parasitóides de ovos de B. cranaodes. Os levantamentos foram realizados de janeiro de 2000 a novembro de 2001, coletando posturas em folhas de macieiras, Hortência (Hydrangia macrophyla) e Hera (Hedera sp.), em Fraiburgo, Santa Catarina. No período, foram observadas 6,6% de posturas parasitadas, sendo que, destas, 22,3% dos ovos estavam parasitados. Os parasitóides foram identificados como Trichogramma pretiosum Riley. Este é o primeiro registro de ocorrência de T. pretiosum parasitando ovos de B. cranaodes em pomares comerciais de macieira no Brasil.

Apple leaf roller, Bonagota cranaodes (Meyrick) is native from South America and it is one of the most important apple pests in Brazil. Its control is exclusively done by insectides and biological control isn't frequently applied. In this way is necessary to know the parasitoids associated with apple leaf roller. The objective of this study was to detect the parasitism occurrence on B. cranaodes eggs in the State of Santa Catarina (Brazil). From January 2000 to November 2001; 1,700 masses were collected on leaves of apple tree, Hydrangea macrophyla and Hedera sp. in Fraiburgo, Santa Catarina State. During this period egg parasitism was registered in 6.6% of masses where 22.3% of the eggs suffered parasitism. The parasite identified was Trichogramma pretiosum. This is the first record of parasitizing of Trichogramma pretiosum in B. cranaodes eggs in commercial apple orchards in Brazil.

O caupi (Vigna unguiculata (L.) Walp) é um alimento básico das populações do Nordeste brasileiro, devendo merecer atenção com vistas a melhoria da qualidade de grãos, resistência a doenças e pragas e aumento de produtividade. Este trabalho teve por objetivo estudar a variabilidade e o potencial genético de 28 linhagens, escolhidas após uma seleção para cor, tamanho de grãos e resistência a viroses. A produtividade apresentou coeficiente de variação genético de 23,90%, e o valor agronômico, de 3,56%. O número de vagens por pedúnculo apresentou a menor estimativa do coeficiente de determinação genético (4,51%), e o peso de 100 grãos, a maior (81,74%). O coeficiente de determinação genético da produtividade foi de 34,15%. As maiores estimativas de ganho genético foram as do peso de 100 grãos (21,73%) e da produtividade (19,77%). As correlações genotípicas foram superiores às fenotípicas e às de ambiente, destacando-se as correlações entre número de ramos secundários e produtividade (68,13%), e valor agronômico e produtividade (100%). Estes resultados mostram amplas possibilidades de seleção entre as linhagens com relação à maioria dos caracteres estudados.

Cowpea (Vigna unguiculata (L.) Walp) is an important food crop for human population in northeastern Brazil. Studies aiming to increase its yield as well as to improve the grain quality and the insect and diseases resistance are needed. This work aimed to accomplish genetic studies in twenty-eight cowpea advanced lines. The studied lines were chosen after selection for seed color and size and plant viruses resistance. The degree of genetic determination ranged from 4.51% (in pods/peduncle) to 81.74% (in 100-seed weight). The seed yield degree of genetic determination was 34.15%. The highest estimates of genetic gain were 21.73% to 100-seed weight and 19.77% to seed yield. The genotypical correlations were higher than phenotypical and environmental ones. High correlations were found between fruiting branches/plant and seed yield (68.13%) and between agronomic value and seed yield (100%). This result indicates the selection feasibility for most of the studied traits.