the protective capacity of the crude extracts from larval and nymphal stages of hyalomma anatolicum anatolicum was examined in the new zealand white rabbits. the rabbits were randomly divided into 3 groups of five animals. the rabbits in groups 1 and 2 were immunized with crude extracts of larval and nymphal antigens, respectively and group 3 was served as control. following challenge of each r...

the population response of heliothis armigera larvae to nuclear polyhedrosis virus (npv) was investigated. the virus was introduced by permitting the larvae to feed on lettuce leaves. median lethal doses (ld50) were determined. the estimated ld50 values for the first, second, third, early, and late fourth larval instars were 5, 141, 1226, 5168 and 24553 polyhedra per larva respectively. in ...

fish larvae have several sensory systems that are functional at or soon after hatching and then are developed further during larval and juvenile stages. this study was conducted to investigate development of the eye in rutilus kutum , based on histological and allometric growth analysis during early developmental stages up to 35 day post hatching with emphasis on retinal morphology. for this pu...

Bay anchovy (Anchoa mitchilli) have been reported in several systems to display net up-estuary larval movements, against the mean flow. However, the means by which such transport occurs is poorly understood. We address how estuarine circulation and larval behaviors serve to transport larvae of the bay anchovy. In two successive summer seasons, we conducted multiple near-synoptic samples of larv...

With recent findings of grass carp Ctenopharyngodon idella in tributaries of the Great Lakes, information on developmental rate and larval behavior is critical to efforts to assess the potential for establishment within the tributaries of that region. In laboratory experiments, grass carp were spawned and eggs and larvae reared at two temperature treatments, one "cold" and one "warm", and track...

The influence of environmental variables on the planktonic growth, pelagic larval duration and settlement magnitude was examined for the coral reef surgeonfish Acanthurus chirurgus. Newly settled fish were collected daily from patch reefs in the San Blas Archipelago, Caribbean Panama for 3.5 years. Environmental influences on growth were examined at three different life history stages: from 0 t...

The life cycle of Rhipicephalus evertsi evertsi Neumann, 1897, is discussed under the following headings: larval feeding; larval drop; nymphal feeding; nymphal drop; nymphal moulting; adult feeding; adult drop; preoviposition period; oviposition period and incubation. Special attention has also been given to the development of both male and female reproductive organs, gametogensis and mating.

Variation in larval supply to disjunct marine populations can provide insight into larval transport and delivery mechanisms, especially when compared with observations of physical transport. Daily variability in larval supply at two mussel-dominated hydrothermal vents, East Wall and Choo Choo, near 9u509N, East Pacific Rise, was quantified concurrently with hydrodynamic observations to investig...