Ayres de Oliveira Menezes

Compatibility of the fungus Beauveria Bassiana (Bals.) Vuill. (Deuteromycetes) with extracts of neem seeds and leaves and the emulsible oil

A compatibilidade de uma formulacao comercial de oleo emulsionavel de nim (Azadirachta indica A. Juss.), do extrato aquoso de sementes e do extrato aquoso de folhas de nim com Beauveria bassiana (Bals.) Vuill., foi avaliada in vitro. Foram conduzidos tres experimentos para avaliar o efeito de cada um dos produtos no crescimento vegetativo do fungo, e na producao e viabilidade dos conidios. Os produtos foram incorporados ao meio de cultura (PDA+E) e distribuidos em placas de Petri, nas concentracoes, 0,15; 1,5 e 15% (extrato aquoso de folhas), 1; 2 e 4% (extrato aquoso de sementes) e 0,5; 1 e 1,5% (oleo emulsionavel). Com base no crescimento vegetativo e na producao de conidios, os extratos aquosos de sementes e de folhas e o oleo emulsionavel de nim foram caracterizados segundo o modelo T para classificacao de compatibilidade de produtos. Os extratos de sementes e de folhas mostraram-se menos prejudiciais a B. bassiana que o oleo emulsionavel. Esse produto, nas concentracoes testadas, nao foi compativel com B. bassiana, inibindo significativamente o crescimento vegetativo e reduzindo a producao e a viabilidade dos conidios com efeitos mais acentuados nas concentracoes mais altas. Os extratos de sementes e de folhas de nim foram compativeis com o entomopatogeno em todas as concentracoes testadas. O extrato de sementes reduziu o crescimento vegetativo e a producao de conidios, mas nao afetou a viabilidade dos esporos produzidos. Embora o extrato de folhas a 15% tenha reduzido um pouco o crescimento vegetativo e a producao e viabilidade dos conidios, ainda se manteve compativel com o fungo B. bassiana, segundo o modelo T.

Morfologia externa dos estágios imaturos de heliconíneos neotropicais: I. Eueides isabella dianasa (Hübner, 1806)

External morphology of the immature stages of neotropical heliconians: I. Eueides isabella dianasa (Hubner, 1806). The external features of egg, larva and pupa of Eueides isabella dianasa (Hubner, 1806) (Lepidoptera, Nymphalidae, Heliconiinae) are described and illustrated, based upon light and scanning electron microscopy.

Feeding preferences of Microtheca punctigera (Achard) (Coleoptera: Chrysomelidae) for some Brassicaceae plants in multiple-choice assays

Host plant feeding preference is important basic information for the development of insect management strategies. Multiple-choice feeding preference assays were conducted in the laboratory for the chrysomelid beetle, Microtheca punctigera (Achard). Feeding was assessed 72 h after onset of experiments. With one larva per Petri dish, food items comprised watercress, Nasturtium officinale L., arugula, Eruca sativa L., mustard, Brassica juncea Cosson, Chinese cabbage, B. pekinensis (Lour.) Rupr. and wild radish (Raphanus raphanistrum L.). Feeding ranking preferences were Chinese cabbage, mustard, wild radish, arugula and watercress (7.97, 1.85, 0.98, 0.36 and 0.11 mm2, respectively). Feeding on Chinese cabbage was 4.31 times more intense than on mustard. The same experiment was repeated with one adult per dish. Responses of males and females were quite similar. Feeding was higher on mustard (87.2 and 142.8 for males and females, respectively). Feeding on arugula (51.5 and 132.7) and Chinese cabbage (51.8 and 89.0) were intermediate. Watercress (22.96 and 39.3) and wild radish (12.03 and 28.4) were the least preferred host plants. In a third experiment, ten larvae per dish were used and spinach, Tetragonia expansa Murr., radish, Raphanus sativus L. and collard, B. oleracea var. acephala L., were also included. Daily larval frequencies on each food were also measured. Feeding was similar on Chinese cabbage and mustard (47.89 and 53.78, respectively). Number of insects was greater on mustard, Chinese cabbage and wild radish. Probable explanations for results and proposals for further investigations are discussed.

Ocorrência de Lysiphlebus testaceipes (Cresson) (Hymenoptera: Aphidiidae) parasitando pulgões (Hemiptera: Aphididae), em trigo em Medianeira, PR

This paper records the occurrence of Lysiphlebus testaceipes (Cresson) attacking aphids in wheat plantation in Medianeira, in the west region of Paraná State, Brazil. This microhymenoptera was introduced and released by Embrapa Trigo, from 1978 to 1992 in the wheat production region at the state of Rio Grande do Sul, what suggests that individuals of this species may show high dispersal ability.

Abundância de inimigos naturais de pulgões do trigo em diferentes distâncias da borda da mata

The objective of this work was to assess the abundance of natural enemies of wheat (Triticum aestivum) aphids at different distances from the edge of the forest (2.0 to 200 m), in the municipalities of Londrina and Ibipora, in the state of Parana, Brazil, in the 2008 crop season. A total of 11,316 aphids, 682 mummies, 487 parasitoids, and 20,366 predators were quantified. The effect of the distance from the edge of the forest on aphids and parasitoids was not consistent. Among predators, the Dolichopodidae family was the most abundant (87.74 and 98.55% in Ibipora and Londrina, respectively) and showed a higher population near the edge of the forest, indicating that this refuge area favors that predator.