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 ...

Population genetics and phenotypic structures are often predicted to vary along the geographic range of a species. This phenomenon would be accentuated for species with large range areas, with discontinuities and marginal populations. We herein compare the genetic patterns of central populations of Coccinella septempunctata L. with those of two phenotypically differentiated populations consider...

Studies regarding the determination of population trend of Lipaphis erysimi (kalt.) and its associated natural enemies in different Brassica lines along with the effect of gamma radiation on their population were conducted at Agricultural Research Farm, Malakandher, Khyber Pakhtunkhwa Agricultural University Peshawar during spring 2006. Three different Brassica lines F6B3, F6B6 and F6B7 were us...

Early-tier studies are the initial step in the environmental risk assessment of genetically engineered plants on nontarget arthropods. They are conducted in the laboratory where surrogate species are exposed to higher concentrations of the arthropod-active compound than those expected to occur in the Þeld. Thus, early-tier tests provide robust data and allow to make general conclusions about th...

A 5 yr study in the semiarid wheat production region of eastern Washington documented the relative densities of pest aphids and their natural enemies in cereal production systems using on-farm replicated plots. The systems were reduced-tillage soft white winter wheat (SWW) (Triticum aestivum L.)—summer fallow rotation; no-till soft white spring wheat (SWS)— chemical fallow rotation; continuous ...

this paper is an attempt to fill all of previous literature of coccinellidae records and species distribution in different provinces of iran. distribution was extracted for each species from literatures. there are 6 subfamilies, 16 tribes, 32 genus and 117 species in iran. the largest subfamily, tribe and genus in iran were scymninae, scymnini and scymnus, respectively. the most distribution wa...

The planting of transgenic crops expressing Bacillus thuringiensis endotoxins is widespread throughout the world; the prolific increase in their application exposes nontarget organisms to toxins designed to control pests. To date, studies have focused upon the effects of Bt endotoxins on specific herbivores and detritivores, without consideration of their persistence within arthropod food webs....

Diabrotica spp. (Coleoptera: Chrysomelidae) beetles and southern green stink bugs, Nezara viridula (L.) (Heteroptera: Pentatomidae), are pests on corn, Zea mays L., and soybean, Glycine max (L.) Merr., as well as on cucurbits. Control of these insects has depended on chemicals. An alternative to chemical control is the use of biologicals. Use of bacteria, fungi, viruses, pheromones, and metabol...