The genus Noctuiseius Prasad is synonymized with Otopheidomenis Treat. Two new species, Otopheidomenis kayosiekeri and Otopheidomenis pholusis, are described and illustrated. O. kayosiekeri is known from Honduras, Panama Canal Zone, and Peru from the sphingid moths Pachylia darceta, P. resumens, and Triptogon lugubris. O. pholusis is known from Bolivia and Honduras from the sphingid moths Pholus sp., P. anchemolis, and P. obliquus. A key to the known species of Otopheidomenis is included.

Random counts of the white grubs, Phyllophaga fusca Froelich and P. anxia LeConte, in a permanent meadow did not conform to the Poisson distribution, there being an excess of uninfested and highly infested sample units over the expected number. But when the negative binomial series was fitted to the observed distribution, the discrepancies were not significant when tested by chi-square. Using a common k, the distribution of the various stages may be described by expansion of (q-p)−k, when values of k are as follows: egg 0.15, first instar 0.41, second instar 1.30, third instar 2.00, pupa 1.62, teneral adult 1.30. Aggregation resulted from the clumping of eggs at oviposition, and randomness increased with dispersal of the larvae. For all stages, the variance was proportional to a fractional power of the mean. Three transformations are offered for stabilizing the variance of field counts.

The morphology and fine structure of the stylets, labial clamp, and crumena of the balsam woolly aphid, Adelges piceae (Ratz.), are described from sections studied in the electron microscope.

Unmated female A. kühniella (Zell.) emitted a sex pheromone at the beginning of the light period of a 24 hour cycle of light and dark periods. There were no differences apparent in the duration of the calling posture by females in light of 1, 40, or 200 lux. A sex pheromone was extracted from the abdominal tips of unmated females of various ages with organic solvents, 3-day-old females gave the most potent extracts. Extracts of equal potence were obtained from females at different times during the diel cycles of photoperiod. The response of males to the extract was maximal at dawn, increased with age for 5 days, and was greater in light of 1 lux intensity than of 200 lux. Both sexes showed an anticipation of the beginning of the light period in their sexual behaviour, but if the timing of the cycle of photoperiod was changed the behaviour of both sexes became synchronised to the new cycle on its second or third occurrence.

The following new Chrysauginae are described: Mimetauge n. gen., type-species M. napeogenalis n. sp., a mimetic species from Peru; Zaboba unicoloralis n. sp., California; Caphys arizonensis n. sp., Arizona. Acallis mitchelli Dyar is transferred to Zaboba.

A review and analysis of the literature showed that precipitation, or its absence, can regulate the numbers of or the damage by insect pests of annual crops in Canada in essentially four main ways: as soil moisture, when the insects are in the ground; as a mechanical factor that impinges directly on them when they are exposed; through its effects on foodplants; and through its effects on natural enemies of the pests. Though any one pest species may be influenced by two or more of these processes and in different ways by each depending on the stage of its life cycle that is affected, usually only one way is significant. Precipitation is so far of little value in forecasting pest situations reliably, but water in various forms has much potential for use as a pest control agent.

The droplet range of a water spray is conveniently described by trapping the droplets in a viscous polybutene, measuring their diameters with an image-splitting eyepiece, calculating cumulative percentage volume and cumulative percentage number, plotting both on log–log paper, and noting the mass median and number median diameters. A ratio, MMD/NMD, is suggested as useful for comparing sprays.

Autogenous Aedes atropalpus (Coquillet) females derived from larvae fed on a standard maximum diet, matured about the same numbers of eggs when supplied with water only or with 25% sucrose. Those maintained on water laid 56% of the number matured within 5 days of emergence, but the sugar-fed insects laid only 28% in the same time, and even after 35 days many were found to have retained their eggs. The physiological mechanism causing the delay was not associated with crop distention, nor with the nutritional changes brought about by ingested sugar.Nulliparous females mostly refused blood during the first ovarian cycle although a few did rake a blood meal. At the time of feeding the eggs were already mature and neither the protein nor carbohydrate of the host blood were utilized during the first ovarian cycle. Parous females fed on blood and used the protein for egg development and there was a rapid rise in haemolymph carbohydrate after feeding, indicating that the host blood sugars also were used immediately.Nullipars derived from larvae maintained on a very low diet did not seek a blood meal either, and in these only some eggs commenced development to various stages. Sugar feeding by these adults assisted both maturation and oviposition.

Larger populations of the European red mite, Panonychus ulmi (Koch), developed on artificially infested young peach trees protected by screen windbreaks than on unprotected trees. In the laboratory rather high air velocities were required to blow mites off the leaves. Agitation of leaves without contact between them had no effect on the mites. Whipping of leaves back and forth caused appreciable mortality of mites on them, and mortality was further increased when the leaves could beat together. It was concluded that wind causes considerable mortality of mites in peach orchards mostly through friction between leaves.

Counts of the cabbage maggot, Hylemya brassicae (Bouché), on cabbage did not conform to the Poisson distribution, there being an excess of uninfested and highly infested plants over the expected number. But when the negative binomial series was fitted to the observed distribution, the discrepancies were not significant when tested by chi-square. The negative binomial parameter k tended to increase with density. Using a common k, the distribution of the various stages may be described by expansion of (q − p)−k, when values of k are as follows: egg 0.78, larva 0.71, pupa 0.84. Three different transformations are offered for stabilizing the variance of field counts.

Individuals of Psyllaephagus richardsi n. sp., related to P. arbuticola Gahan and Waterston, are described. Specimens were reared from nymphs of Aphalara steironemicola Richards n. sp., described previously, collected from Steironema ciliatum (L.) (Primulaceae) at Constance Bay, Ont., Canada.

Two new species of Forcipomyia (Lasiohelea) and three new species of Forcipomyia (Thyridomyia) are described in all stages.Saunders’ "Lasiohelea complex" is reviewed and is here suggested to be restricted to Kieffer’s Lasiohelea (s. lat.) and to comprise the following Forcipomyia subgenera: Synthyridomyia, Thyridomyia, Lasiohelea, Dacnoforcipomyia and the subgenus represented by Lane’s Lasiohelea stylifer Lutz.It is also suggested, pending further evidence, that Lasiohelea be returned to its original generic status.

An improved cage arrangement resulted in 73% of the female European pine shoot moths being mated during a 48-hour test. Key factors were continual airflow from females to males and a light-to-dark illumination change. The ponderosa pine tip moth, Rhyacionia zozana (Kearf.), the black-headed budworm, Acleris gloverana (Wlsm.), and two species of spruce budworm, Choristoneura occidentalis Freeman and C. viridis Freeman, were also tested in the apparatus with some success in every case.

The synthetic ability of type-A neurosecretory cells (NSC) and corpus allatum (CA) was investigated autoradiographically in both normal virgin females and those from which the frontal ganglion had been removed. Incorporation of 3H-cystine and 3H-uridine into the NSC was significantly lower in frontal ganglionectomized insects than in controls. There appeared to be no relationship between the level of isotope uptake and the amount of stainable material in the NSC. Ability of the CA to incorporate 3H-uridine seemed unaffected by the operation.

The origins and insertions of the muscles of the gnathosoma, idiosoma, and appendages are illustrated and described. Idiosomal muscles are shown to be associated with external plates and in some cases with the endosternum. The articulations of all legs arc shown. The functions of most muscles are given. The principal muscles of the appendages as revealed in this study are flexor muscles but opposing muscles are shown to be much more common than previously thought. Hydrostatic pressure is apparently responsible for extension of the appendages. The position and function of the endosternum is given.

Populations of Neoseiulus fallacis (Garman) and Phytoseiulus persimilis Athias-Henriot, predators of Tetranychus urticae Koch, were reared under homogeneous environmental conditions by inbreeding without introducing new germ plasm.Mites from 1-year-old inbred cultures had high mortality in all stadia and generally lower viability. Oviposition was reduced and a high percentage of eggs failed to hatch. Further inbreeding resulted in the production of only sterile female mites. These data cast serious doubt on the possibility of genetically improving populations of predaceous mites with only limited germ plasm resources.

A study of sampling variation in field populations of the cabbage maggot, Hylemya brassicae (Bouché), on cabbage in Ontario, revealed that inter-plant and block differences were rarely significant. For the immature stages, the most appropriate sample unit was the plant root together with a 4- to 6-in. diameter core of soil. The number of samples required was inversely proportional to population density; this relationship was graphed for three levels of sampling precision.The insect is bivoltine in eastern Ontario but has three generations in the southwestern part of the province.

Some individual processes, e.g., moulting, in the development of Panonychus ulmi (Koch) can proceed at temperatures as low as 7.2 °C but not at 6.3 °C. the threshold for complete postovarial development lies between 9.2° and 11.7 °C. The threshold for deposition of viable eggs is between 10.7° and 11.7 °C, though some females eclosing at 7.2 °C lay inviable eggs at 9.8 °C. Experimental values obtained in the determination of threshold temperatures can be expressed as two temperatures: the permissive, the lowest experimental temperature allowing a particular process to proceed; and the inhibitive, the highest experimental temperature (below the permissive) preventing completion of the process. The actual threshold lies between these temperatures.

The following new taxa are described: Limbobotys n. gen., type-species Botys limbolalis Moore; L. hainanensis n. sp., Hainan; L. foochowensis n. sp., Foochow; Nephelobotys n. gen., type-species Pionea nephelistalis Hampson; Circobotys malaisei n. sp., N. Burma; Vittabotys n. gen., type-species V. mediomaculalis n. sp., Kwangtung and Fukien.