Although there is a great deal of literature on the relative potencies of many insecticides to various insects and although many histological and physiological studies of insects have been made, observations on tissue changes in insects caused either directly or indirectly by insecticides have been few (Pilat, 1935 and Hartzell, 1945). Such observations are important in advancing our knowledge of specialized insect histology and, therefore, of insect physiology. They are of further value because they provide indications of the mode of action of insecticides on insects, a knowledge which is of great importance not only in the development of exact as opposed to indiscriminate methods of application, but also in the development of new and more specific insecticides.

The number and volume of feeding and oviposition holes made by female white pine weevils, Pissodes strobi (Peck), on lateral branches of resistant and susceptible Sitka spruce, Picea sitchensis (Bong.) Carr., were determined. When all possible effects of weevil reproduction on feeding rates were eliminated, by using reproductively noncompetent weevils, there was no significant difference in the number of feeding holes made on the two host types. In addition, the volume of feeding holes was unaffected by host type on day 1. In contrast, when differential reproductive activity was induced by treating weevils with juvenile hormone, and the host factor was eliminated, by using only the susceptible host, higher reproductive activity was accompanied by a significantly larger number of feeding holes. Hormone treatment also led to an increase in the volume of feeding holes in the absence of any influence of host factors. Results are interpreted in relation to the direct effects of host resistance on feeding rates (which determine host acceptability) and the indirect effects of host resistance on feeding rates mediated through the physiology of the weevils (which determine host suitability). Our results show that both the number of feeding holes and their volume are determined primarily through weevil metabolism.

Outbreaks of geometrid defoliators in subarctic birch forest in Fennoscandia often occur at high altitude in a distinct zone along the tree line. At the same time, moth larvae may not have an impact on the forest at lower altitude. Directly adjacent outbreak and nonoutbreak areas offer unique opportunities for studying the underlying mechanisms of outbreaks. Within two altitudinal gradients in coastal northern Norway, we investigated whether altitudinal outbreaks might be caused by release from pupal predation by ground-dwelling invertebrates such as harvestmen (Opiliones), spiders (Araneae), rove beetles (Coleoptera: Staphylinidae), carabid beetles (Coleoptera: Carabidae), and other beetles (Coleoptera). We predicted a consistently higher abundance of such generalist predators at low versus high altitudes. Our results did not support this prediction. There was no consistent altitudinal variation in the abundance of predators that could be related to zonal moth outbreaks in the birch forest slopes. In addition, none of the predator groups investigated showed any numerical response to a distinct outbreak of winter moth that took place during the course of the study. Consequently, localised moth outbreaks at the altitudinal tree line in northern Norway cannot be explained by the release from pupal predation by the predator groups examined here.

In my paper on the nymph of Cinygma integrum (1933, Can. Ent. LXV, 73) there is a rather serious error which I wish to correct. At the time my material was limited to a single nymphal exuvia; now with the mature nymphs and more exuviae at my disposal I find that the peculiar nature of the maxillae, as described and figured in the above paper, was abnormal and probably brought about by contraction occurring during the process of making a slide of the mouth-parts.

We tested the hypothesis that slow rewarming would improve the ability of Drosophila melanogaster Meigen (Diptera: Drosophilidae) larvae to survive acute low-temperature exposure. Four larval stages (1st, 2nd, and 3rd instars, including wandering-stage 3rd instars) of four wild-type strains were exposed to –7 °C for periods of time expected to result in 90% mortality. Larvae were then directly transferred to their rearing temperature (21 °C) or returned to this temperature either in a stepwise fashion (pausing at 0 and 15 °C) or by slow warming at 1 or 0.1 °C/min. We observed a reduced rapid cold-hardening effect and no general increase in survival of acute chilling in larvae rewarmed in a stepwise or slow fashion, and we hypothesize that slow rewarming may result in accumulation of chill injuries.

Xylem sap tension, an indication of moisture stress, was compared in foliated twigs of white fir infected by the mistletoe, Phoradendron bolleanum subspecies pauciflorum, and in paired, uninfected fir at the lower, mid-, and upper crown level. The upper boles were examined for fir engraver attacks. Reproductively successful attacks containing little or no host oleoresin were found in the infected fir, while only a single unsuccessful attack filled with oleoresin was found in the uninfected trees. Mean moisture stress in the upper crowns of most of the infected fir exceeded that in uninfected trees in all paired comparisons except one with a light infection. No differences in mean moisture stress between infected and uninfected trees were found at the lower and mid-crown levels.

QM, a tumor-suppressor gene, plays an important role in cell growth, differentiation, and apoptosis. In this report, a homologue of human QM was isolated from the ant Polyrhachis vicina Roger. The full-length cDNA of P. vicina QM (PvQM) is 827 base pairs (bp) and contains a 5′-untranslated region of 91 bp and a 3′-untranslated region of 77 bp. The open reading frame of PvQM encodes a deduced 219-amino acid peptide with a predicted molecular mass of 25.1 kilodaltons. The results of sequence alignments indicate that the PvQM protein shares an overall identity of 76.7%–98.2% with other known QM homologues, and is most closely related to that of Apis mellifera L. (Hymenoptera: Apidae). Real-time quantitative reverse transcription - polymerase chain reaction was performed to compare PvQM mRNA expression during P. vicina development and within different castes. The data revealed that PvQM mRNA is differentially expressed during P. vicina development, with the highest expression level in embryos and the lowest in late-instar larvae and pupae. The levels of PvQM transcripts also vary among castes, with higher levels in workers and lower levels in both males and females. These results suggest that PvQM is developmentally and caste-specifically regulated at the level of transcription.

Two hundred and thirty-nine primary types of Ceraphronoidea (11), Evanioidea (1), Proctotrupoidea (226), and Trigonaloidea (1) housed in the Canadian National Collection were examined and listed. These were contributed by the following authors: Masner (108), Townes (41), Muesebeck (25), Harrington (16), Johnson (9), Dessart (7), Huggert and Masner (6), Masner and Huggert (5), MacGown (5), Johnson and Masner (3), Ritchie and Masner (3), Mineo (2), Provancher (2), Ashmead (1), Bin and Johnson (1), Dessart and Bin (1), Fouts (1), MacGown and Nebeker(1), Sharkey (1), and Viereck (1). Lectotypes are designated by L. Masner for the following Harrington species: Aphanogmus salicicola, Lygocerus pallipes, Aclista caudata, Eritrissomerus pallipes, Sactogaster varipes, Baryconus bicolor, and Baryconus cinctus; and for Pentacantha canadensis Ashmead. The following new generic combinations are also proposed by L. Masner: Acanosema caudata (Harrington) and A. crassicornis (Harrington) from Aclista; Amblyaspis pallipes (Harrington) from Eritrissomerus; and Trimorus canadensis (Ashmead) from Pentacantha.

The monoterpenes (±)-α-pinene, (1S)-(−)-β-pinene, (R)-(+)-limonene, and myrcene did not enhance the catch of red pine cone beetle, Conophthorus resinosae, in traps baited with the female sex pheromone, (±)-trans-pityol. Traps placed in the upper half of the tree’s crown caught significantly more beetles than those hung from the tree’s trunk 2 m above ground. No significant differences in trap catches were found among standard yellow Japanese beetle trap tops and those painted red, green, blue, white, black, or yellow.

The following is a list of Hemiptera taken at Hudson Heights, Quebec, during the seasons of 1941 and 1942 between June 7 and September 21. Hudson Heights is located on the Ottawa River approximately nine miles west of where that river meets the St. Lawrence River, and approximately 80 miles east of Ottawa.

A striking new species, Agriotypus himalensis, is described from Assam (India) at 7200 ft in the Himalayas. The family Agriotypidae is maintained as distinct because of the structure of the adult abdomen and larval head.

Ether extracts from Eurygaster integriceps (Evlakhova and Chekhourina 1962) and Bombyx mori (Koidsumi 1957) have been found to inhibit germination of conidia of the white muscardine fungus, Beauveria bassiana, and of Aspergillus flavus, respectively. Free fatty acids, such as caprylic acid, which inhibit the germination of B. bassiana conidia (Smith and Grula 1981), have been found on the cuticle of several insects (Smith and Grula 1982; Saito and Aoki 1983). However, Smith and Grula (1982) found that the toxicity of free fatty acids to B. bassiana conidia in vitro is dependent on the nutritional conditions present. The germination of B. bassiana conidia onthe integument of the mountain pine beetle, Dendroctonus ponderosae, is seldom observed without nutrient enhancement (Hunt et al. 1984). My objective was to determine whether the relative absence of conidial germination on D. ponderosae cuticle is due in part to the action of toxic free fatty acids.

Mating is necessary to bring about ovarian maturation in females of Anthocoridae and related taxa (Cimicidae). The objectives of this study were to determine how forced delays in mating affect extent and rate of oocyte development, duration of the preoviposition period, and levels of lipid reserves in three species of Anthocoris. Extent of oocyte development by unmated females differed among the three species. In unmated A. tomentosus, the basal oocyte failed to show any increase in size with increasing female age, whereas oocytes in unmated A. nemoralis and A. whitei exhibited some growth beginning 2 days after eclosion. One consequence of these differences among species is that a forced delay in mating (of 3 or 10 days) had less of an effect on A. whitei and A. nemoralis than on A. tomentosus, in terms of the length of the preoviposition period measured from the time of mating. Mated females of A. nemoralis and A. whitei grew larger oocytes than unmated females within 2 days of mating, whereas the same phenomenon took 4 days in A. tomentosus. Embryos became visible in the eggs of mated A. nemoralis and A. whitei 2–3 days after mating, compared with 5 days after mating for A. tomentosus. Mature eggs with egg caps were visible within 3, 4, and 6 days after mating for A. nemoralis, A. whitei, and A. tomentosus, respectively. In all three species, unmated females 10 days after eclosion had significantly higher levels of lipids allocated to nonreproductive tissues than similarly aged females that had been mated on the day of eclosion, suggesting that there was a trade-off between allocation of resources to eggs and allocation to somatic reserves.

Cicindela hirticollis Say 1817 is associated with shoreline and riverine sand deposits and is widely distributed in North America. Geographic variation in this species was analyzed by multivariate analysis of size, elytral markings, and color data obtained from some 4000 specimens from 75 sites throughout the species distribution. Eleven subspecies are recognized and discussed: C.h. hirticollis Say, gravida LeC., ponderosa Thorns., abrupta Csy., rhodensis Calder, corpuscula Rumpp, shelfordi, athabascensis, coloradula, couleensis, and siuslawensis Graves. Possible Pleistocene réfugia, and redistribution of the species following continental glaciation are discussed. Theoretical advantages of certain variants in particular climates or on certain substrates, are considered. Cicindela hirticollis has been eliminated or is endangered in many of its former habitats due to human activities.

Five new subspecies are described: C. h. shelfordi (type locality: Guthrie, OK) which inhabits the Great Plains region; C. h. athabascensis from the Lake Athabasca Sand Dunes of Saskatchewan and Alberta; C. h. coloradula from the Little Colorado River, AZ; C. h. couleensis (type locality: Vantage, WA) which is distributed in the Columbia–Snake river system of Washington, Oregon, and Idaho; and C. h. siuslawensis (type locality: Florence, OR) which inhabits the Pacific coast of Oregon and Washington.

Eight species of Ciconiphilus from the Ciconiiformes and Anseriformes are discussed and illustrated; two of these are newly described: melanolophi. (type-host: Gorsachius m. melanolophus) and cygni (type-host: Cygnus cygnus). New synonymies include: quadripustulatus (Burm.) (= maculipes Gieb., planiceps Piag., cingulatum Piag.); temporalis (Piag.) (= femoratum Piag.); decimfasciatus (B. & L.) (= nyctarde Denny, obscurum Gieb., castaneum Piag., boisduvali Eichler, doriabagla Ausari). C. matosi (Tendeiro) is a new combination. A key is given to the species.

Procedures are outlined for evaluating in aquaria the effects of insecticides against rheophilic species of Trichoptera larvae (Brachycentrus lateralis (Say), Hydropsyche morosa Hagen, and H. recurvata Banks). In general DDT, DDD, and methoxychlor were considerably more toxic than were malathion, Baytex®, or diazinon and their regression lines were steeper. Some of the methoxychlortreated larvae recovered within 18 hours after treatment but the reverse was true for DDT, DDD, and the organophosphates. DDT dissolved in ethanol was considerably more toxic than any of the three commercial formulations of DDT tested. Sensitivity to DDT declined (i.e.LC50 values were higher) with increasing size (age) of the larvae. LC50 values of DDT also varied directly with the densities of tested populations in tests containing more than 10 larvae per 250 ml of water. Toxicities of all chlorinated hydrocarbons varied indirectly with the temperature and those of the organophosphates directly. The significance of these findings to laboratory and field tests is discussed.

A modified Ladell apparatus is described which offers a low cost and efficient method of wetland macroinvertebrate extraction. Soil and leaf litter samples, immersed in Mg2SO4 solution, are subjected to agitation and bubbling to promote the extraction of macroinvertebrates. A further modification provides salt solution recycling. Fourteen floodplain taxa were recovered with extraction efficiencies ranging from 80 to 100% at a cost of 15–20 cents (U.S.) per sample.

During the spring of 1933, an adult convergent ladybird beetle, Hippodamia convergens Guerin, was placed in a 3-dram homeopathic vial with a number of nymphs of the potato psyllid, Paratrioza cockerelli (Sulc). The ladybird immediately grabbed a psyllid nymph and began to eat it. Ten fifth-instar psyllid nymphs were eaten by this predaceous beetle during the one and one-half hours that it was caged with the nymphs. It was noted that moving nymphs were taken more quickly than those at rest, but the beetle showed no reluctance at taking the scale-like nymphs which were quietly feeding.

Geocoris bullatus (Say) adults were observed on two separate occasions dragging adult flea beetles over the soil surface, with one of the flea beetles being identified as Phyllotreta striolata (F). No predation was seen on other occasions when this predator and flea beetles were present together in the field, nor in laboratory confinement experiments. Under the latter circumstances G. bullatus readily attacked aphids, however. It seems likely that G. bullatus is only an incidental predator on adult flea beetles in western Canada.