biological reactions of the two-spotted spider mite (tss), tetranychus urticae, were studied on nine cultivars of tomatoes. the spider mites were reared on leaf discs, taken from fruiting stages of the host plants. the effects of feeding on some tomato cultivars, namely: long shelf life, meran (greenhouse cultivars), redclude, western red, imperial, yazd, mazandaran, west azarbaijan and khorasa...

1. Plant defence of Viburnum shrubs against oviposition by its specialist herbivore, the viburnum leaf beetle [VLB Pyrrhalta viburni(Paykull)], involves an egg-crushing wound response in twigs. Although the response is variable among Viburnum species, it can have a strong impact on egg survivorship. Beetles typically aggregate egg masses with conspecifics along infested twigs, forming clusters ...

chrysoperla carnea is a voracious predator. it is currently mass-reared and released for biological control programs. this study was aimed at finding out the effect of different diets on biological characteristics of adult predator, and to introduce a better and cheaper artificial diet for its mass-rearing. in order to obtain a pure and physiologically homogenous population, the predator was re...

Physogastric queens of Melipona marginata were removed from their colonies in order to verify the acceptance of a new queen by workers. Colony strength was evaluated according to queen oviposition rate and comb diameters. Replacement was observed seven times. Its occurrence and speed related positively to colony strength, independently of queen's age. In weak colonies, queen replacement was obs...

Bovine blood inoculated with bacteria isolated from screwworm [Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae)]-infested animal wounds was tested as an attractant for oviposition for gravid screwworms. Eight species of gram-negative coliform (Enterobacteriaceae) bacteria mixed with bovine blood singly or all species combined and incubated for various times produced volatiles that at...

Teneral adults of Dinoderus porcellus were raised in the laboratory and exposed to various temperature regimes 10, 15 20, 30, 35 and 40 C respectively. Four dried yam species Dioscorea rotundata, Dioscorea alata, Dioscorea dumetorum and Dioscorea cayenensis were used, to determine the effect of temperature on oviposition and developmental stages of the insect. At 10C, there was no oviposition, ...

The egg production and development of Amphibolus venator (Klug) were investigated at five temperatures (25, 27.5, 30, 32.5 and 35°C), 70% r.h. and 16L–8D photoregime. The optimum temperature for multiplication and development of A. venator was around 32.5°C. Pre-oviposition period decreased with increasing temperature. Temperature in the range 25–35°C had no effect on oviposition period. The av...

The present study was performed to elucidate whether mesotocin (MT), one of avian neurohypophysial hormones, relates to the action of arginine vasotocin (AVT) on oviposition of hens. The ratio of AVT-induced oviposition was increased when 1 microg/hen of MT was injected together with AVT. An intravenous injection of 1 microg/hen of MT caused an increase in the binding affinity of the uterine AV...