The sterols in the trophosomes of Romanomermis culicivorax and Neomesomermis flumenalis were identified and compared with the sterols in the haemolymph of their larval insect hosts, Aedes aegypti and Simulium venustum, respectively. The C26 sterol 22-trans-24-norcholesta-5, 22-dien-3 beta -ol was pr...

This paper (only an abstract of which is given) was presented at the Sixteenth Annual Meeting of the Society of Nematologists held at East Lansing, Michigan, from 16 to 19 August 1977. An account is given of studies carried out in Canada on the effect of parasitism by the mermithid nematode Neomesom...

R. culicivorax juveniles were dissected out of Aedes aegypti larvae 7 days after infection and incubated under controlled conditions in isotonic saline containing a 14C-labelled fatty acid (palmitic acid), monoacylglycerol (glycerol monoolein), or triacylglycerol (glycerol tripalmitate) nutrient sou...

Eggs (0-24 h old and 48-72 h old) of Choristoneura fumiferana were treated topically with fenoxycarb dissolved in acetone. Only 25% of treated eggs hatched, compared to 90% of control eggs. Survival of larvae from treated eggs to induction of diapause in the 2nd instar, and of diapausing larvae, was...

Isocitrate lyase and malate synthetase, key enzymes of the glyoxylate cycle, were present in postparasites of R. culicivorax. Specific activities of enzymes were higher in adult postparasites than in newly emerged juveniles. Isocitrate lyase had a well-defined pH optimum (7.5), whereas malate synthe...

The effect of 7 juvenile hormone analogues on the development of larvae of Choristoneura fumiferana was studied in the laboratory at 23 degrees C, LD 16:8 and 65% RH by topical application of the compounds to early 6th-instar larvae. Fenoxycarb showed the highest potential for control, with an LC50 ...

Four isolates (= 3 species) of steinernematids were propagated at 25, 20 and when possible, 15 and 10 degrees C for 2 years, then their capacities for tolerating high temperatures and freezing determined. In all isolates, the temperature at which 50% of the infective juveniles died (LT50) increased ...

R. culicivorax larvae, dissected out of Aedes aegypti larvae 7 days after infection, were incubated under controlled conditions in isotonic saline containing 14C-U-palmitic acid to investigate the nature of the transport mechanism(s) used by the nematode for transcuticular uptake of palmitic acid. N...

The effects of methoprene on post-feeding larvae of Delia radicum was investigated. Treatment of larvae with methoprene at 1 micro g did not affect the capacity of the insect to pupate, but suppressed eclosion to the adult stage. The concentration of haemolymph trehalose was significantly decreased ...

Laboratory studies in Newfoundland showed that the endocrinology of last-instar larvae of Prosimulium mixtum Syme & Davies and P. fuscum Syme & Davies infected with the mermithid parasite Neomesomermis flumenalis was unaffected by the parasitism and that slight disturbances in the endocrinol...

The nutrient composition of postparasitic females (newly emerged juveniles, newly moulted adults, and spent adults) and eggs of Romanomermis culicivorax was studied. Postparasites were obtained from experimentally infected larvae of the mosquito Aedes aegypti. Throughout postparasitic development, p...

The relative concentrations of catecholamine in the nervous system of Romanomermis culicivorax were measured under different experimental conditions by a glyoxylic acid-induced fluorescence procedure. A greater concentration of catecholamine was recorded in the nervous system of adult males and fema...

Laboratory studies showed that the insect growth regulator Altosid 5E, applied at doses ranging from 5 to 50 ppb did not interfere with the preparasitic, parasitic or postparasitic development of Romanomermis culicivorax, a mermithid parasite of mosquitoes. Both Altosid 5E and R. culicivorax were se...

The effectiveness of topical applications of the juvenile hormone analogue fenoxycarb against selected stages of Choristoneura fumiferana was determined. Fenoxycarb prevented eggs at an early stage of embryogenesis (0-24 h old) from hatching, and these eggs were more sensitive to the compound than o...

This review covers the classification, life history, physiological and pathological host-parasite relationships, and biological control potential of mermithid and rhabditid nematodes parasitic in simuliid flies. West African strains of Simulium damnosum now developing resistance to Abate are obvious...

When larvae of Aedes aegypti (L.) infected with Romanomermis culicivorax were fed on a diet low in quantity or protein content or both, the number of postparasites that emerged from the hosts decreased and host mortality increased marginally. Parasitic development was prolonged and became asynchrono...

A description is given of an axenic laboratory method for rearing Choristoneura fumiferana larvae that is suitable for physiological studies. The rearing procedure is a modification of the method of D. G. Grisdale (1984), using a wheat-germ based synthetic diet. The axenic rearing method resulted in...

Cellulose acetate electrophoresis was used to determine the degree to which isozyme banding patterns differed among 4 strains of steinernematid nematodes that had been recycled or stored at 5, 10, 15, 20 and 25 degrees C: Steinernema feltiae Umea strain, S. carpocapsae A11 strain, S. riobravis [S. r...

Diflubenzuron 25% w.p. applied at concentrations (0.001, 0.01, 0.1% w/v), which were effective against laboratory populations of the anthomyiid Delia radicum, did not affect the hatching of the eggs of its predator and parasitoid, the staphylinid Aleochara bilineata. Applied externally in distilled ...

Histochemical investigations showed that Romanomermis culicivorax in experimentally infected larvae of Aedes aegypti (L.) were found to accumulate storage products, primarily in the trophosome, from the fourth day of parasitic development onwards. Lipids constitute the predominant storage metabolite...

Newly hatched larvae of Aedes aegypti (L.) were experimentally infected with controlled numbers of Romanomermis culicivorax and reared at 27 deg C on 4 types of diet (low or high protein diets, ad libitum or restricted in quantity). The numbers of parasites emerging from the mosquitoes were signific...

Insects of both agricultural and medical and veterinary importance are included in this review of control of insects by nematodes. Information is collected on entomophilous nematodes that are of potential use for the regulation of insect populations, and recent progress made in investigations design...

The kinetic properties of two metabolic enzymes, glucose-6-phosphate dehydrogenase and hexokinase, were studied in 4 strains of entomopathogenic nematodes that had been recycled for two years at various temperatures: Steinernema feltiae NF strain, S. feltiae Umea strain, S. carpocapsae. All strain, ...

Eggs of Delia radicum 24-28 h old were treated with the same doses of 4 insect growth regulators. Diflubenzuron significantly reduced egg hatch as compared with untreated and solvent-treated controls. Methoprene had a delayed effect, preventing hatching of adults from pupae that subsequently develop...

Distribution of caudal papillae in adult Romanomermis culicivorax was determined by scanning electron microscopy. Ninety-eight caudal papillae, each containing one pore, were present in males but absent in females. Papillae were arranged in 3 longitudinal rows, one ventral and 2 ventrolateral; the m...