BACKGROUND RNA interference (RNAi) is a valuable reverse genetics tool to study gene function in various organisms, including hemipteran insects such as aphids. Previous work has shown that RNAi-mediated knockdown of pea aphid (Acyrthosiphon pisum) genes can be achieved through direct injection of double-stranded RNA (dsRNA) or small-interfering RNAs (siRNA) into the pea aphid hemolymph or by f...

Seasonal occurrence of aphids and aphidophagous insects was monitored for six years (2006 2011) from full leaf expansion in May to leaf fall in October variety pecan trees that were not treated with insecticides. Aphid outbreaks occurred two times per season, once in the spring and again in the late summer. Yellow pecan and blackmargined aphids exceeded the recommended treatment thresholds one ...

The green peach aphid (Myzus persicae), a plant pest, and gray mold disease, caused by Botrytis cinerea, affect vegetables and fruit crops all over the world. To control this aphid and mold, farmers typically rely on the use of chemical insecticides or fungicides. However, intensive use of these chemicals over many years has led to the development of resistance. To overcome this problem, there ...

The evolution of visual warning signals is well known in animals but has received scant attention in plants. The coevolutionary hypothesis is the most influential hypothesis on warning signals in plants proposing that red and yellow leaf colours in autumn signal defensive strength to herbivores. So far, evidence in support of the hypothesis, which assumes a coevolutionary origin of autumnal lea...

In 1990 and 1991, populations of the cabbage aphid, Brevicoryne brassicae, and the green peach aphid, Myzus persicae, were monitored on broccoli interplanted with three leguminous cover crops (the living mulches) and compared with broccoli without cover crop (clean cultivation). The cover crops used were white clover ( Trifolium repens L.), strawberry clover (Trifolium fragiferum L.) and a mixt...

Current anticholinesterase pesticides were developed during World War II and are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (AChEs) in insects and in mammals. A sequence analysis of AChEs from 73 species and a three-dimensional model of a malaria-carrying mosquito (Anopheles gambiae) AChE (AgAChE) reported here show that C286 and R339 of AgAChE are ...

Aphids are one of the most destructive pests in crop production such as pepper, cucumber, and eggplants. The importance of entomopathogenic fungi as alternative pest control agents is increasing. Conidia of entomopathogenic fungi are influenced by environmental conditions, such as temperature and relative humidity, and cause slow and fluctuating mortality. These factors have prevented wider app...

A fluorescent viral clone of the polerovirus Turnip yellows virus (TuYV) was engineered by introducing the Enhanced Green Fluorescent Protein (EGFP) sequence into the non-structural domain sequence of the readthrough protein, a minor capsid protein. The resulting recombinant virus, referred to as TuYV-RTGFP, was infectious in several plant species when delivered by agroinoculation and invaded e...