background : considering the disadvantages of chemical insecticides, we aimed to evaluate vorticella parasites for control of mosquito larvae of anopheles stephensi and aedes aegypti at different larval stages. methods: vorticella sp infected mosquito larvae were crushed in the 0.85% saline and homogenized well to get vorti­cella in suspension. the effects of vorticella sp infections on larval ...

Despite the blossoming interest in host-microparasite epidemiology, and in use of viruses in the biological control of insect pests, few empirical studies have attempted to quantify transmission and mortality rates under field conditions. We report a laboratory and field study in which the transmission parameter (v) and mortality rate (Ux) due to nuclear polyhedrosis virus (NPV) are measured in...

The sweetpotato whitefly, Bemisia tabaci (Gennadius), B biotype, presents a unique problem for vegetable growers by serving as a vector of plant viruses and by inducing physiological disorders of leaves and fruit. An action threshold of a single whitefly is necessary because of the threat of disease in many areas and growers rely heavily on a single class of insecticides (neonicotinoids) for wh...

Despite the blossoming interest in host-microparasite epidemiology, and in use of viruses in the biological control of insect pests, few empirical studies have attempted to quantify transmission and mortality rates under field conditions. We report a laboratory and field study in which the transmission parameter (v) and mortality rate (Ux) due to nuclear polyhedrosis virus (NPV) are measured in...

Studies were conducted to compare preference among Bemisia tabaci Gennadius, biotype B instars for parasitization by Eretmocerus mundus Mercet and Encarsia pergandiella Howard when provided one instar only, two different instars, and four different instars simultaneously. In the single-instar no choice treatment, Er. mundus was more successful in parasitizing the younger host instars, while En....

A peculiar new genus of Ortheziidae is described from Queensland, Australia. Acropygorthezia williamsi LaPolla & Miller, n. gen. & sp. was discovered in two localities in the nests of Acropyga myops. Descriptions and illustrations are provided for the adult female, adult male, first-instar nymph, prepupa, and pupa; descriptions only are provided for the secondand third-instar nymphs. Prior to t...

For many insect species, group living provides physiological and behavioral benefits, including faster development. Bed bugs (Cimex lectularius L.) live in aggregations composed of eggs, nymphs, and adults of various ages. Our aim was to determine whether bed bug nymphs reared in groups develop faster than solitary nymphs. We reared first instars either in isolation or in groups from hatching t...

Inconspicuous prey pay a cost of reduced feeding opportunities. Flowers are highly nutritious but are positioned where prey would be apparent to predators and often contain toxins to reduce consumption. However, many herbivores are specialized to subvert these defenses by retaining toxins for their own use. Here, we present a model of the growth and life history of a small herbivore that can fe...