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,...

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...

in vitro lymphocyte responses of high responder (hr) and low responder (lr) guinea pigs from pe-ripheral blood lymphocytes (pbl) to parasite antigens soluble protein third stage larvae (spl3) and soluble protein adult stage ( spa), non-parasite antigen ovalbumin (ova) were examined. there was substantial differences between hr and lr guinea pigs in the rate of acquisition of responsiveness to t...

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 ...

cystic hydatid disease (hydatidosis) is the most serious tape-worm infection prevalent in the cattle and sheep raising area of the world. hydatidosis in man (as an accidental host) caused by infection with the ova containing larval stage of echinococcus spp. in the last decade different techniques have been employed for the serological diagnosis of hydatid disease, such as iha, ifa, elisa, ccle...

Background The Mantispidae are a distinctive group of Neuroptera known for the adults' possession of raptorial forelegs. There are four recognised, extant subfamilies of Mantispidae: the Mantispinae, Symphrasinae, Calomantispinae and Drepanicinae. The life history and larval behaviour of the subfamily Mantispinae is best known: the immatures are spider egg predators. Among the three remaining s...

International efforts are underway to establish well-connected systems of marine protected areas (MPAs) covering at least 10% of the ocean by 2020. But the nature and dynamics of ocean ecosystem connectivity are poorly understood, with unresolved effects of climate variability. We used 40-year runs of a particle tracking model to examine the sensitivity of an MPA network for habitat-forming col...