Observations by Dobzhansky's group in the 1940s suggesting that the presence of recessive genotypes could account for lower larval developmental rates in Drosophila melanogaster were not confirmed at the time and all subsequent investigations on this subject focused on the analysis of ecological models based on competition among pre-adult individuals. However, a paper published in this journal ...

while the «classical insecticides» (ddt: dieldrin, malathion, etc.) mainly affect the adult stage of insects, dimilin belongs to a new group of insecticidal compounds that kills the insect in its larval stages, but has no lethal affect on the adult insect. its empirical formula is c14h9h2~f2cl. diflubenzuron is proposed as common name for the trade name dimilin. studies were made on c. pipiens,...

Cross-shore exchange of plankton plays an important role in marine ecosystems and coastal communities. Larvae of many intertidal invertebrate species grow offshore and come back to the shore for settlement by crossing the energetic surf zone; however, shoreward transport mechanisms are not well understood. To test the possible onshore transport mechanisms, numerical simulations were performed b...

Some marine invertebrate larvae expand the range of settlement cues to which they will respond as they age. How do relatively simple larvae achieve such complex changes in behaviour? Larvae of the Australian sea urchin Holopneustes purpurascens settle and metamorphose specifically in response to a settlement cue, dissolved histamine, produced by the host alga Delisea pulchra. Older H. purpurasc...

Conflict arises among social organisms when individuals differ in their inclusive-fitness interests. Ant societies are excellent models for understanding how genetic relatedness mediates conflict intensity. However, although conflicts within colonies typically arise over offspring production, the role of larvae as actors in social conflict has received little attention. We develop and empirical...

Oestrus ovis (L.) (Diptera: Oestridae), the nasal bot fly, has a relatively short free-living life cycle outside of the host, and therefore it is necessary to know when the parasitic period occurs in order to prevent the clinical signs and economic losses caused by this parasite. The length of this parasitic portion of the life cycle is quite variable: a few weeks to several months depending on...

The bipartite life history of most marine organisms leads to complex patterns of replenishment in benthic populations. High variation in adult spawning, dynamic oceanographic currents, and often unknown larval behaviors create challenges in accurately predicting spatial and temporal patterns in the supply and settlement of pelagic larvae to nearshore juvenile habitats. Yet, understanding and pr...

Movement of individuals is a critical factor determining the effectiveness of reserve networks. Marine reserves have historically been used for the management of species that are sedentary as adults, and, therefore, larval dispersal has been a major focus of marine-reserve research. The push to use marine reserves for managing pelagic and demersal species poses significant questions regarding t...

On the basis of patterns of anterograde, retrograde, and bi-directional transport of tracers from both the superior olivary nucleus (SON) and the torus semicircularis (TS), we report anatomical changes in brainstem connectivity across metamorphic development in the bullfrog, Rana catesbeiana. In early and late stages of larval development (Gosner stages 25-37), anterograde or bi-directional tra...

The genetic variation and diversity among fifty-eight polyvoltine silkworm genotypes was estimated by using ten economic traits. The results revealed that the single shell weight showed higher genetic variation such as PCV% (17.20%), GCV% (12.93%), and heritability (56.5%) followed by single cocoon weight, shell ratio and matured larval weight. The D2 (Mahalonobis? distance) statistics reveal...