BACKGROUND RNA interference (RNAi) is an effective tool to examine the function of individual genes. Carboxylesterases (CarE, EC 3.1.1.1) are known to play significant roles in the metabolism of xenobiotic compounds in many insect species. Previous studies in our laboratory found that CarE expression was up-regulated in Aphis gossypii (Glover) (Hemiptera: Aphididae) adults of both omethoate and...

Pea aphid (Acyrthosiphon pisum) clones have been shown to be adapted to particular host plant species but it is unknown whether there are host races. A 1101 base pair region of the mitochondrial cytochrome oxidase I gene (COI) was sequenced for 21 pea aphid clones that had been collected from different host plants in Canada and the U.S.A. Only five closely related mitochondrial haplotypes were ...

The natural occurrence of entomophthoralean fungi pathogenic towards aphids on cereal and potato crops was investigated in the years 2009, 2010, and 2011. Infected aphids were sampled in three bioclimatic zones in Tunisia (Beja, Cap bon, and Kairouan) and fungal species were determined based on morphological characters such as shape, size, and number of nuclei in the primary conidia. Polymerase...

The benzoylphenyl urea insect growth regulators (IGRs), diflubenzuron, alsyston, CGA 112913, UC 62644 and Thuringiensin, were tested on adult and late third instar Trioxys pallidus and first instar walnut aphids. The organophosphates, phosalone and azinphosmethyl were used as positive controls. The IGRs and Thuringiensin were not acutely toxic to adult and larval Trioxys when contact, topical a...

Aphids harbour both an obligate bacterial symbiont, Buchnera aphidicola, and a wide range of facultative ones. Facultative symbionts can modify morphological, developmental and physiological host traits that favour their spread within aphid populations. We experimentally investigated the idea that symbionts may also modify aphid behavioural traits to enhance their transmission. Aphids exhibit m...

population dynamics of three main alfalfa aphids, namely: pea aphid, acyrthosiphon pisum (harris), spotted alfalfa aphid, therioaphis trifolii forma maculata (buckton), black alfalfa aphid, aphis craccivora koch, and their most abundant predators and parasitoids in three sites and in two subsequent years in isfahan, iran, were investigated. the results revealed that frequency and temporal occur...

Artificial aphid diets have been previously developed for the pea aphid, Acyrthosiphon pisum (Harris), and the green peach aphid, Myzus persicae (Sulzer). The ability to rear aphids on an artificial diet allows for selectively adding or subtracting compounds from an aphid's food source to determine the effect on fecundity and longevity. Five diets previously developed for the green peach aphid ...

Most aphids possess intracellular bacteria of the genus Buchnera. The bacteria are transmitted vertically via the aphid ovary, and the association is obligate for both partners: Bacteria-free aphids grow poorly and produce few or no offspring, and Buchnera are both unknown apart from aphids and apparently unculturable. The symbiosis has a nutritional basis. Specifically, bacterial provisioning ...

The cucumber mosaic virus (CMV) 2b protein not only inhibits anti-viral RNA silencing but also quenches transcriptional responses of plant genes to jasmonic acid, a key signalling molecule in defence against insects. This suggested that it might affect interactions between infected plants and aphids, insects that transmit CMV. We found that infection of tobacco with a 2b gene deletion mutant (C...

ants consume or store the honeydew which is secreted by aphids or other homopteran insects. major benefit of ant attendance for aphids is protection against natural enemies. a study was carried out during 2009-2010, to determine the mutualistic association between ants and aphids on different host plants in some parts of khuzestan and esfahan provinces. a total of 20 ant species belonging to 12...