This study was conducted to determine the insecticidal activity of essential oils from oregano, Origanum onites L. (Lamiales: Lamiaceae), savory, Satureja thymbra L. (Lamiales: Lamiaceae), and myrtle, Myrtus communis L. (Rosales: Myrtaceae) against three stored-product insects. Essential oils from three species of plants were obtained by Clevenger-type water distillation. The major compounds in these essential oils were identified using gas chromatography-mass spectrometry and their insecticidal activity was tested against adults of the Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), the Indian meal moth Plodia interpunctella Hübner (Lepidoptera: Pyralidae) and the bean weevil Acanthoscelides obtectus Say (Coleoptera: Bruchidae). While the major compound found in oregano and savory was carvacrol, the main constituent of the myrtle was linalool. Among the tested insects, A. obtectus was the most tolerant species against the essential oils. However, the insecticidal activity of the myrtle oil was more pronounced than other oils tested against A. obtectus adults. The essential oils of oregano and savory were highly effective against P. interpunctella and E. kuehniella, with 100% mortality obtained after 24 h at 9 and 25 µl/l air for P. interpunctella and E. kuehniella, respectively. LC50 and LC99 values of each essential oil were estimated for each insect species.

F(1) males from irradiated pupae were more sterile than parental males. To prevent larval emergence from irradiated eggs, a dose of 350 Gy is required. The same dose is required to prevent the larvae from reaching the adult stage.

No abstract

We report the results of experiments conducted with Ephestia kuehniella Zeller to determine the effects of gamma radiation on life stages. Eggs, larvae, pupae and adults were irradiated with increas-

Ephestia kuehniella adults were stored at 10°C for 1-10 weeks. Reproductive ability and number of living adults decreased depending on the length of the storage period. Long-term exposure to cold lengthened the life of the adults and 50% mortality was reached after 6 weeks. To obtain complete mortality and sterility 10 weeks of storage was needed. The larvae reared on corn Xour diet developed to the adult stage more rapidly than that of the other treatments. The adults reared on oat Xour produced signiWcantly more eggs than the other diets. There was no diVerence among diets with regard to emergence rate, longevity or sex ration of E. kuehniella adults. Trichogramma evanescens did not diVerentiate among hosts from diVerent food sources with respect to parasitization, adult emergence and sex ratio. The suitability of the eggs from cold-exposed adults with respect to parasitization was found to be the same as the control during the Wrst 3 weeks.