developmental periodsof thegrapevine aphid, aphis illinoisensis shimer (hemiptera: aphididae) on the grape, vitis vinifera l., and its two parasitoid species, lysiphlebus testaceipes (cresson) (exotic) (hymenoptera: braconidae: aphidiinae) and aphelinus albipodus hayat and fatima (indigenous) (hymenoptera: aphelinidae) were studied at two constant temperatures (20 and 25 ± 2 oc), 70 ± 5 % r.h. ...

The flower fly species, Eupeodes nuba (Wiedemann, 1830) (Diptera: Syrphidae) is crucial for agroecosystems as it provides various ecosystem services such pest control through the use of predatory larvae and crop pollination by adults. In this research, consumption rate different instars Aphis fabae (Scopoli, 1763) E. has been studied under laboratory conditions at 25±2 °C, 60±10% humidity (RH)....

Arthropod predators and parasitoids provide valuable ecosystem services in agricultural crops by suppressing populations of insect herbivores. Many natural enemies are influenced by non-crop habitat surrounding agricultural fields, and understanding if, and at what scales, land use patterns influence natural enemies is essential to predicting how landscape alters biological control services. He...

Parasites and pathogens are crucial in shaping immune systems. Many animals especially insects have outsourced part of their function to protective symbionts. There is good evidence that, akin systems, parasites shape the occurrence diversity symbionts that likewise, can parasites. Such a relationship should result correlation between symbiont parasite nature. Aphids well known for possessing p...

In this study, researchers studied the evolutionary effects on parasitoids of symbiont-mediated resistance by Acyrthosiphon pisum to the parasitoid, Aphidis ervi. They were able to take advantage of the parthenogenic life cycle of the aphid, allowing them to effectively rule out host evolution as the factor effecting results. They performed several experiments to determine what evolutionary eff...

A plant's performance and interactions with other trophic levels are recorgnized to be contingent upon plant diversity and underlying associational dynamics, but far less is known about the plant traits driving such phenomena. We manipulated diversity in plant traits using pairs of plant and a substitutive design to elucidate the mechanisms underlying diversity effects operating at a fine spati...

The nectar provision hypothesis predicts that the introduction of nectar-producing plants in agroecosystems benefits parasitoid populations field and enhances biological control. Intercropping is a common crop diversification scheme may bring complementary sources for parasitoids increase herbivore pest For instance, intercropping cereals with faba beans introduces usually sugar-devoid systems ...

nasonovia ribisnigri (mosely) is one of the most important pests of the lettuce plant and it was reported for the first time in ahvaz in 2008. in order to investigate the dominant species of its natural enemies and their population fluctuations, sample were taken arbitrarily from fifty plants twice a week during the growing season in 2010-2012. in this study, ten species of predators, three spe...