Differences in the behavior of scale insects induced by their host plants has been observed, principally, in uniparental, bisexual, univoltine species. Behavior in endoparasites of such species also may be thus modified. The phenomena involved, reproductivity, sexuality, voltinism and, with the parasites, host-regulation, are related to the environmentally induced immunity of the host plant to its indigenous scale insects.This immunity, when not a regional phenomenon, is necessarily sporadic. When operative, it may he as complete as generic-immunity. Periodic host plant non-susceptibility is considered to he a physiological response to meteorological and edaphic conditions, a response usually rendering the plant temporarily unsuitable for coccid development. The interpolation of immune periods in the life of a coccid’s normal host plant necessarily disrupts the continuity of the host-regulative action of the coccid’s parasites. Host plant pheno-immunity was first clearly manifested in regions where Lecanium corni Bouché, L. tiliae (Linnaeus), and Saissetia oleae (Bernard) free of their regulative parasites, reproduced in great abundance. In regions to which these coccids are indigenous the limitation of their outbreaks to artificial monocultures attested to the obscure nature of host plant pheno-immunity. The cessation of host plant immunity to coccids, the subsequent heavy reinfestation, and then the parasitic elimination of the outbreak attested to the host-regulative power of parasitization.

The heat requirements for diapause termination in pupae of Hyphantria cunea are subject to a high degree of generic control. Offspring–parent regression analysis based on a positively assortative mating pattern, which is the normal pattern in field populations of this species, provides a slope of 0.60. Positive skewness in the distribution of heat requirements can be reduced by conversion to logarithms. The inheritance of heat requirements is sex-linked, with the female being the heterogametic sex. Fitness characters that are significantly correlated with heat requirements affect larval and pupal survival rates and the weight of both male and female pupae. When the effects of these correlated survival rates are removed mathematically, the slope of the offspring–parent regression is increased to 0.80.Changes in the heat requirements of natural populations, in relation to the amount of heat available each year, influence their survival rates. The comparison of actual and calculated changes, based on models for heritability and selection pressures, will be the subject of a later paper in this series on H. cunea.

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.

Cohort life tables are seen to provide the basis for an analytic and insightful approach to the rational management of crop pests. A life table is presented for a typical planting of early market cabbage, and dx values appraised in the light of potential dollar revenues.

Water deposited on peach leaves as a constantly replenished film for 48 hr killed few European red mites, Panonychus ulmi (Koch), by drowning. Considerably more, especially of larvae, were lost by their coming loose from the water-covered leaf surface and floating off; the proportion thus lost did not differ greatly between 6- and 48-hr treatments. Relative humidity of 100% and to a lesser degree, 96–99%, inhibited activity and development.

Pachylobius picivorus (Germar) is one of the weevils which is assuming increased importance as a pest of natural and planted pine seedlings. Brood development requires from 100 to 128 days during the summer. Weevils are long lived, with oviposition occurring at a rate of approximately 0.7 eggs per day per female for the life of the insect. There are two population peaks during the year in the Georgia Piedmont. These peaks reflect the response of the weevils to temperature and to developmental cycles.

Enoclerus sphegeus Fabricius adults were most abundant on trees infested with Dendroctonus ponderosae Hopkins in May and June of 1966 and 1967. Greatest numbers of adults were observed on the bole from 0 to 5 ft aboveground, apparently in response to the activity of other scolytids. In the laboratory, each adult killed about 1 D. ponderosae per day, and each larva killed about 25 D. ponderosae during development. Mean larval densities were generally less than 0.2 per square foot at four different sampling heights on the tree bole during the overwintering period. Densities were greatest at all heights in July. Maximum larval density was observed at the 1.5-ft height. Larvae began leaving the trees for pupation sites in July of both years. It is estimated that adult clerids consume less than 1% of the adult beetle population during their attack period and the clerid larvae kill 5–11% of the beetle brood.

Methanol, acetaldehyde, and ethanol have been identified in extracts of attractive wood and bark. The attractancy induced by anaerobic treatment in both sapwood and phloem of conifers and broadleaf trees was characterized by ethanol as the most concentrated component. In laboratory bioassays, ethanol was attractive at low concentration to both sexes of Trypodendron lineatum (Olivier). Methanol and acetaldehyde, at the concentrations found, apparently play no role in attraction. Monoterpenes had a repellent effect on T. lineatum.

Intensive studies on the population dynamics of the birch leaf miner, Fenusa pusilla (Lepeletier), were carried out in two stands of blue birch at the Morgan Arboretum, Macdonald College, Que., from 1964 to 1966. Life tables for nine and two generations, respectively, showed that mortality of the immature stages was lower on 3- to 5-year-old trees than on 9-year-old trees. The analysis of successive age-interval survivals in relation to generation survival revealed that predation during the late larval stages was the key factor in generation survival of the insect on the younger trees. Desiccation of the leaf during the early larval stages along with predation were key factors on the older trees.

Flight orientation about the yaw axis (induced by rotation of a striped bowl) in the squash bug, Anoplecnimes curvipes (Heteroptera), is brought about by differential changes in wing-stroke amplitudes and wing-stroke planes of the two sides. The metathoracic leg of the inner side in a turn is displaced in the transverse plane while the contra-lateral leg remains in the normal flight posture. The probable mode of control of the two wing parameters effecting yaw is discussed.

Life histories of Conophthorus beetles attacking the shoot tips of jack, red, Scotch, and ponderosa pines were studied and compared with the life history of the red pine cone beetle, Conophthorus resinosae Hopkins. The tip-infesting beetles have not been morphologically separated from C. resinosae. The beetles attacking the shoots of jack, red, Scotch, and ponderosa pines have similar life histories which differ from that of C. resinosae. The latter is distinctly univoltine, while the tip-infesting beetles appear to be bivoltine. Also, dates of appearance and seasonal development differ.

Behavioral differences between a Conophthorus beetle attacking jack pine shoot tips and the red pine cone beetle, C. resinosae Hopkins, were studied. In field experiments the red pine cone beetle attacked cones and shoots of both pines but preferred cones over shoots and red pine cones over jack pine cones. The jack pine tip beetle attacked both jack pine and red pine snoots, but no progeny appeared in red pine shoots. In laboratory tests, the red pine cone beetle survived equally well in vapors of simulated red and jack pine shoot resin, while the jack pine tip beetle survived best in the jack pine resin vapor. The jack pine tip beetle is described as a new species, Conophthorus banksianae McPherson.

The female of Amblyseius duncansoni n. sp., is described and illustrated. It was taken in Nova Scotia from the bark of dormant apple trees in early winter and prior to bud burst.

Holotypes, lectotypes, and syntypes of pyralid moths of the subfamilies Nymphulinae, Scopariinae, Cybalomiinae, Odontiinae, Evergestinae, and Pyraustinae studied by the author at the Zoological Institute of the Academy of Sciences of the USSR in Leningrad in 1964 are catalogued. Types of 93 names are discussed; lectotypes are designated for 54 nominal species; 13 nominal species are listed for which type material could not be located. Four names are considered to be nomina nuda.

Comparisons were made of frequency distributions of Ips avulsus (Eichh.) and Ips grandicollis (Eichh.) caught in window traps while these species were attacking fresh pine slash. Relationships between mean and variance of trap data indicated that the flight of I. avulsus was more highly aggregated than the flight of I. grandicollis. Three different indices of aggregation were calculated which quantitatively expressed the degree of flight aggregation in each species. Degree of aggregation during attack may be an index of aggressiveness since it determines beetle density which influences attack success on a living host. The relatively high degree of flight aggregation of I. avulsus may partly explain why this species is more frequently a killer of live trees than is I. grandicollis.

A national survey shows that the merchant grain beetle, Oryzaephilus mercator Fauvel, has been present in Canada since at least 1925 and that it has become firmly established as a household pest of processed cereal products preferably of high oil content, but has not been reported from stored grain. A related species, the saw-toothed grain beetle, Oryzaephilus surinamensis (L.), infests both stored grain and processed cereal products. Illustrations are provided to show the morphological characters by which the two species may be recognized and separated.

The most suitable temperature for larval development of Aedes vexans Meigen was found to be 25 °C. At this temperature 86% of the larvae survived and pupated in 7 days. At 10°, 15°, 20°, and 30 °C larval development time was 46, 22, 10, and 8 days and survival rates were 17, 56, 74, and 71%, respectively. At 5 °C mortality was 100% in the first-instar stage, the last larva dying 12 days after hatching. Adults emerged in 2 to 5 days after being transferred into water at 25 °C, males emerging 2 days before the females.

In mid-July 1969, an extremely heavy population of the yellow-collared scape-moth, Cisseps fulvicollis (Hübner), was observed in a 45-acre field of grain corn at Napierville, Que. Larval feeding was heavily concentrated on the lower leaves of the plants, leaving only the mid-rib of the leaves unattacked. Approximately 92% of the pupae were parasitized by Itoplectis conquisitor (Say) and Ichneumon sp. of the group winkleyi, thereby reducing the moth population quite substantially. From samples of ears taken at harvest in the unattacked and infested portions of the field, the reduced yield was evaluated at about 7%.This is apparently the first published record of this amatid moth as an economic injurious insect on grain corn in Canada.

Logs of lodgepole pine (Pinus conforta Dougl. var. latifolia Engelm.) supporting immature Dendroctonus ponderosae Hopkins were maintained under conditions of non-fluctuating temperature and light. The rate of emergence of the adult beetles exhibited a rhythmic, possibly circadian, emergence pattern. When the temperatures fluctuated the emergence rate was always greatest in higher temperature.