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: Beauveria bassiana as an entomopathogenic fungi showed high effects on the aphid Aphis crassivora and the white fly Bemesia tabaci infesting cucumber. A dose of 1 mg.ml−1 killed 100% of either insects. Lower doses showed lower effects. Nymphs of the two insects were markedly affected by treatment of the fungi. The total duration and the number of survivors were significantly decreased by an increase in the dose of the pathogen. Latent effects were clearly observed in the resulting adults. Adult longevity, period of reproduction and fecundity were markedly decreased by an increase of B. bassiana dose. The increase in dose of the pathogen increased the resultant winged form of A. crassivora up to 91.7% at 0.5% mg.mr−1.

A series of investigations have been carried out on the effect of the entomopathogenic fungus Beauveria bassiana on the various developmental stages of Phthorimaea operculella. Both first and second instar larvae were more susceptible than the third or fourth instars. The infected prepupae and pupae resulted in marked decrease in the emergence, longevity of moths, deposited eggs and their egg hatchability. An obvious increase in the pupal duration was observed and the resulting malformed adults were also recorded. The latent effects were markedly obvious, specially in high doses of Beauveria bassiana.

Larvae of Phthorimaea operculella Zell., Anagasta kuehniella Zell. and Triboliurn confusum Duv. were used successfully after paralizing them for rearing the two anthocorid predators Orius albidepennis and 0. laevigatus. The three hosts were found sufficient for normal development of the predators and for excess of egg production. The deposition of eg s was clearly raised and the mortality appeared during the nymphal stages of the predators because opthe strong twisting and resistance in case of the living host larvae was nearly avoided. The obtained numbers of adult predators were markedly increased by using this method of paralizing host larvae.

The interaction between Plodia interpunctella Hbn., parasites and predators and Bacillus thuringiensis Berl. has been investigated. Experiments with the parasite Bracon brevicornis Wesm. previously fed during the larval instar on treated host larvae of P. interpunctella, showed significant reduction in the egg production. The egg incubation and larval duration of the parasite were not affected except at the highest concentration (500 μg). Percentage of formed cocoons was significantly reduced at all tested concentrations. The longevity of either sex, on the other hand, was also reduced. The percentage of hatching among the deposited eggs, significantly decreased with the increase of the concentration. Investigations with adult parasite fed on treated honey solution showed a significant reduction in the number of eggs deposited, hatching among the deposited eggs, percentage of formed cocoons, the percentage of adult emergence and the longevity of the female parasite, was also reduced with the increase of concentrations. With respect to the predator Xylocoris flavipes (Reuter), it was found that the number of consumed host larvae of P. interpunctella by nymphs of the predator decreased with the increase of the concentration of δ‐endotoxm present on the larval food. The nymphal duration was prolonged as the concentration increased from 32–500 μg/g of diet. On the other hand, the longevity of male predator was shortened while that of female was not affected. The consumption of prey larvae by one couple of the predator was reduced only at higher concentrations (250–500 μg). The egg production and hatchability of eggs were also reduced. Studies with the adult stage of the predator showed similar effects with respect to the longevity of the female adults. Also the average consumption of one couple was reduced and an obvious effect on egg production was detected but in varying degrees correlated with the concentration. The hatching of eggs increased as the concentration used decreased. Zusammenfassung Wirkung von Bacillus thuringiensis Berl. auf Parasiten und Predatoren von Plodia interpunctella Hbn. Es wurden die Beziehungen zwischen Plodia‐Parasiten und ‐Predatoren einerseits und Behandlungen der Plodia‐Larven mit Bacillus thuringiensis andererseits untersucht. Experimente mit der Schlupfwespe Bracon brevicornis Wesm., die als Larve in Plodia parasitierte, zeigten eine signifikante Verringerung der Eiprodukten. Die Ei‐ und Larvenentwicklung des Parasiten wurden nur durch Behandlung der Plodia‐Larven mit der höchsten B. thur.‐Konzentration (500 ug) beeinflußt. Die Kokonbildungs‐Quote wurde bei allen Konzentrationen signifikant verringert. Auch wurde die Lebensdauer beider Geschlechter gesenkt. Das Schlüpfprozent der abgelegten Eier wurde mit zunehmender B. thur.‐Konzentration reduziert. Untersuchungen an adulten Parasiten, die mit behandelter Honiglösung gefüttert waren, zeigten mit zunehmender Konzentration signifikante Verringerungen der Zahl abgelegter Eier, der Eischlüpfquote, der Kokonbildungsquote, der Ad...

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The two antimoulting compounds diflubenzuron and zertel showed an adverse effect on the egg parasitoid Trichogramma evanescens and the aphid lion Chrysoperla carnea. Parasitism by T. evanescens was markedly decreased and the immature stages failed to complete their development. When parasitism took place before spraying the insecticides, emergence of adults, longevity and fecundity markedly decreased. Both insecticides showed adverse effects on the duration and pupation of treated eggs or larvae of Chrysoperla. Adults of C. carnea poisoned with any of the 2 insecticides laid markedly less eggs than normal adults. Zusammenfassung Biologische Aspekte zur Bewertung von Zertel und Diflubenzuron in ihrer Wirkung auf Trichogramma evanescens Westw. und Chrysoperla carnea Steph. Die beiden Häutungshemmer, Zertel und Diflubenzuron, hatten auf den Eiparasiten Trichogramma evanescens und den Blattlauslöwen Chrysoperla carnea eine ungünstige Wirkung. Die Parasitierungsrate von T. evanescens verringerte sich deutlich und die Larvenstadien konnten ihre Entwicklung nicht beenden. Bei der Applikation der Häutungshemmer nach der Parasitierung des Wirts wurden das Schlüpfprozent, die Lebensdauer und die Fekundität von T. evanescens negativ beeinflußt. Auf C. carnea‐Eier und ‐Larven wirkten beide Häutungshemmer ungünstig auf die Länge beider Entwicklungsphasen sowie auf die Verpuppung. C. carnea‐lmagines, die mit behandelter Beute gefüttert wurden, legten signifikant weniger Eier ab als unbehandelte Weibchen.