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...

Some parasitoids deposit chemical signals after oviposition as an indication that the host has already been parasitized. This marking can deter subsequent conspecifics or one’s self from laying eggs in previously exploited hosts, thus reducing the risk of superparasitism. We investigated the egg laying behaviour of the parasitoid wasp Hyposoter horticola. In a laboratory experiment, we tested w...

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...

Argyrotaenia sphaleropa (Meyrick) is associated with various fruit species in South America. This tortricid was first detected in citrus, Citrus sinensis (L.) Osbeck, in Brazil, in commercial groves in northern Paraná, during the 1994/95-crop season. The aim of this work was to study the biology of this lepidopteran under laboratory conditions (28 +/- 2 degrees C, 70 +/-10% UR, 14h photofase) u...

We investigated effects of temperature, at 70% RH, on the reproductive parameters of the parthenogenetic psocid Lepinotus reticulatus Enderlein (Psocoptera: Trogiidae). The lowest fecundity (21) was at 35 C and the highest (41) at 27.5 C. At 22.5, 25, and 27.5 C, peak oviposition rates (eggs/female/week) occurred in week 3 and were 4.7, 6.6, and 7.8, respectively; also 51, 57, and 62%, respecti...