We examined the spatial implications of maximum flight distance for several species of stingless bees. Data suggested that maximum flight distance in Meliponini is a function of body size, especially generalized wing size, which can be estimated through principal component analysis. For six species of stingless bees, flight distances and generalized wing sizes were highly correlated (r = 0.938). This indicates that species of Meliponini occupy an effectively larger area as body size increases, which has important implications in the spatial dynamics of local populations restricted to forest fragments. We also used the fitted linear regression model to estimate the maximum flight distance for 12 other species of Meliponini. The results of this research may provide insights for future studies of biological conservation.
Some properties of a Africanized honeybee venom proteases were determined by enzymatic assays in solution, electrophoresis in SDS-PAGE, and gel filtration. Bee venom extracts were obtained by reservoir disruption, selective dialysis (cut off 12 kDa) to eliminate small components, such as the protease inhibitor present in the venom, and then fractionation of the dialyzed extract by gel filtration on a Sephadex G-100 column. The optimal conditions for the caseinolytic assays were pH 9.5, 2-hour digestion at 37 °C, and 1% casein concentration. The proteolytic activity was also determined by electrophoresis in SDS-PAGE with co-polymerized gelatin with three major bands of 66.0, 41.6, and 25.1 kDa. A principal serine-protease-like mechanism was revealed in the enriched fraction of proteolytic activity
A comparative study of ovarioles number in workers of bees, Apis mellifera L. of 36 backcrosses colonies (Africanized and Italian), and stock, inbred and F1 colonies was carried out. No difference on the number of ovarioles in right and left ovaries of workers from the colonies used was detected. The hybrid bees from F1 generation presented from 2 to 31 ovarioles. The number of ovarioles observed in backcrossed Africanized workers varied from 2 to 56 and from 2 to 117 in the Italian ones. The range observed in these bees may be partially explained by the variability registered in stock colonies (Africanized workers: 2 - 16; Italian workers: 6 - 26) and in F1 colonies (2 - 31).
ABSTRACT:Large scale mass rearing of natural enemies has been a mean of improving biological control in the sugarcane intensive agriculture. Among them, Cotesia flavipes, a gregarious koinobiont endoparasitoid, was imported by Brasil to control caterpillars of the sugarcane borer Diatraea saccharalis. The C. flavipes larval development depends on its association with polydnavirus, which blocks the host defense reaction. To verify if the oviposition sequence (1 st , 2 nd or 3 rd ) and the female condition (mated or virgin) interfere in the number of C. flavipes descendents, 4 th instar caterpillars of D. saccharalis were parasitized. Analysis of the data showed that: a) there is an inverse correlation between the parasitism efficiency and the host reaction (encapsulation); b) the number of caterpillars parasitized by virgin females that released parasitoid larvae in the period from 12 to 15 days was higher than that of caterpillars parasitized by mated females; c) a slight difference between mated and virgin females in relation to the parasitim success was observed; and d) the number of encapsulated parasitoid larvae was higher than that of eggs, suggesting that eggs have a better capacity to overcome the host reaction. In this study, the viability of C. flavipes eggs and larvae in the non-specific host D. saccharalis could be correlated with the oviposition sequence and the female condition.
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