Studies on the courtship behavior of Melanoplus sanguinipes (Fabr.) clearly indicated that the male played the dominant role. The conspicuous waving of antennae and vibrating of hind femora, which form an integral part of the male’s behavioral pattern, did not appear essential for normal coupling. Visual stimuli proved to be of primary importance for ’homing in’ on the female prior to the mounting leap. Blinding the male caused all courtship activities to cease. Males clearly were able to select mature females from immature ones and virgin from mated females. Although further experimental evidence is required for corroboration, it is suggested that this selectivity may have been accomplished by some form of chemical stimulus emitted by the females.

The following notes have accumulated while collecting and naming species of Miridae during the past ten years. The records are chiefly of species where the distribution is new or of special interest, or to give data on host relationships. I wish to take this occasion to acknowledge the assistance I have received from several botanists who have from time to time determined plants for me.

This study was undertaken as part of an investigation of the physical and biological requirements of the white pine weevil Pissodes strobi Peck. The broad aspects of the main problem will be given in a later paper and it need only be mentioned here that the immediate objective was to define the requirements of the weevil in terms of measurable factors of the environment. During the field studies, observed variations in behaviour between individual weevils within the limits of a single habitat indicated the need for additional studies that would permit analysis of behaviour in relation to previous conditioning. The responses of the adult weevils to diffuse and discrete light sources, and the effect of temperature on these responses, were investigated in conjunction with field studies of behavioural changes during relatively stable and variable weather conditions, in an attempt to explain observed weevil movements.

Ethanol and sulcatol (6-methyl-5-hepten-2-ol), primary attractant and population aggregation pheromone, respectively, for Gnathotrichus sulcatus, were deployed alone or in combination on stumps and felled trees in the University of British Columbia Research Forest, Maple Ridge, B.C. On 18 April 1974, four Douglas-fir trees were felled at each of three locations, and four western hemlock trees were felled at each of three other locations. Felled trees and their respective stumps were baited on 26 April. Attacks by G. sulcatus and bark beetles were recorded at weekly intervals until 25 October. G. sulcatus attacks increased rapidly, reaching a maximum in June and July, followed by a steady decrease to October. Attacks by Dendroctonus pseudotsugae, Pseudohylesinus nebulosus, and P. tsugae showed characteristic seasonal trends, but were not correlated to any of the treatments. Over half the G. sulcatus attacks were on stumps, in which attack densities reached 683.5/m2. The greatest numbers of attacks were on stumps and logs baited with sulcatol or sulcatol plus ethanol. There was a significant interaction between sulcatol and ethanol on Douglas-fir but not on western hemlock. Significantly more G. sulcatus attacked ethanol-baited western hemlock stumps and logs than unbaited controls. However, there was no difference between the level of attack on ethanol-baited Douglas-fir and the controls. The role of ethanol is hypothesized to be more of a boring stimulant than a major attractant. Stumps baited with sulcatol and then treated with ethanolic solutions of systemic insecticide could be used to trap and kill field populations, thus reducing numbers of G. sulcatus being transported to log-booming grounds, dryland sorting areas, and sawmills.

The predacious mites of the subfamily Phytoseiinae are common predators of the phytophagous mites in apple orchards in Nova Scotia. There is little information in the literature on the value of these predators in the control of phytophagous mites or on the food necessary for their development and reproduction. Ballard (1953) found that at 78°F. at least two males of Tetranychus bimaculatus Har. were required daily by Typhlodroms fallacis (Garm.) to complete the protonymphal or the deutonymphal instar. The males and mated females consumed daily an average of 3.9 and 7.5 males respectively from the larva1 to the adult stage. Chant (1960) found that T. pyri required 25 larvae of Panonychus ulmi (Koch), during 26 days to complete development at 64°F. in the absence of plant material or free water. These authors did not study the effects of different amounts of food on the development of these two species of phytoseiids.

Pupae of western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), from Kennewick and Roslyn in Washington State, United States of America, were subjected to different soil and air moisture conditions to test the hypotheses that adult emergence from dry and moist soil is similar and is greater and occurs earlier at high than low relative humidities (RHs). Adult fly emergence from 0–57% saturated loam soil did not differ in Kennewick (64.8–75.1%) and Roslyn (81.7–86.6%) populations. Emergence did not occur from 76% saturated loam soil. In a RH experiment using dry soil, emergence of Kennewick flies was highest at 97% RH (76.8%), intermediate at 12–74% RH (66.4–69.6%), and lowest at 3% RH (58.0%). Emergence of Roslyn flies was higher at 97% RH (85.6%) than 3% (69.2%) and 12% RH (74.3%), but it did not differ from that at 33% (76.9%) and 74% RH (79.4%). Flies emerged ∼2–3 days earlier at 97% RH than at 3–12% RH. An unnaturally low RH of 3% caused more flies to be deformed than higher RHs. High emergence of R. indifferens in dry and moist conditions likely contributes to its presence in a wide range of native and nonnative habitats.

Sex pheromone-mediated mating disruption using Isomate-C® pheromone dispensers was evaluated as a means of controlling the codling moth, Cydia pomonella, over three consecutive growing seasons in organically managed blocks of apples at two commercial apple orchards in Ontario. The objective of the study was to determine if mating disruption could be used to stabilize or reduce the amount of damage caused by indigenous codling moth populations. The emission rate of the pheromone dispensers was estimated using volumetric and gravimetric methods. Efficacy of the pheromone treatment was assessed by comparing pheromone-baited trap catches of adult male codling moths in pheromone- and insecticide-treated blocks of apples, and by estimating damage caused by first- and second-generation codling moths in pheromone- and insecticide-treated blocks as well as in small plots of apples where the codling moth was not controlled. The estimated average release rate of pheromone varied from 22.2 to 30.3 mg per ha per h. The seasonal total number of adult male moths trapped in the pheromone-treated blocks was from 3.8 to 25.3% of the number trapped in insecticide-treated blocks; during one season at one farm, no moths were trapped in a pheromone-treated block. Treatment with pheromone did not prevent an increase in codling moth damage. At one farm, damage increased ca. 5-fold during the 3-year study. At the other farm, damage increased ca. 4-fold during two consecutive growing seasons in one block and ca. 4-fold during three consecutive seasons in the other block. At both farms there was a marked increase in the amount of damage between the first and second generations of the pest. Possible reasons for the failure of the pheromone treatment to prevent increases in codling moth damage are discussed.

Examples and data based on the host-parasite complex of the California red scale, Aonidiella aurantii (Maskell), and its parasites in untreated test plots in the citrus areas of southern California, not including the San Joaquin Valley and the desert areas, show the following: (1) Weather does not impose upper limits to host population increase. (2) In areas of favorable weather, certain parasites regulate host population densities at very low levels, other factors also being favorable. (3) The parasite Aphytis lingnanensis Compere is affected by weather differentially with respect to the host, and to varying degrees in different localities. The effects of field weather for each 2-week period of the year on all stages of this parasite individually as well as on population growth in held experimental cages are discussed. Adverse effects of weather on the parasite preclude successful population regulation of the host by the parasite at certain times or in particular areas but the range of the parasite is not restricted. (4) Another parasite, Comperiella bifasciata Howard, has its range restricted by weather and not by competition with other parasites to intermediate and interior citrus growing areas. It is never found along the coast. (5) Yet another parasite, Prospaltella perniciosi Tower, has its range restricted by competition and not by weather although it gives the appearance of being restricted by weather because it occurs only in coastal districts. (6) Examples are discussed of interactions between weather and dust, ants, or chemicals with parasites and hosts which result in various modifications of the abundance of the host and parasites. (7) Examples are discussed of the effect of weather on interactions between competing species of parasites and the host which have resulted in striking modifications of the previous distribution of certain parasites.

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is a pest that causes severe damage to various fruits, generating economic losses. We evaluated its potential geographic distribution under current and future climatic conditions using an ecological niche modelling approach, based on the largest available database on occurrence records for this species. Additionally, we identified areas of risk to agricultural land and crops. Predictions under current climatic conditions indicated that this species is likely to be present across broad swaths of the United States of America, southeastern Asia, southeastern Australia, New Zealand, and Europe. We predict considerable expansion of its potential range for 2050, mainly in the Northern Hemisphere, because of ongoing climate change, under both low and high emissions scenarios.

It is well known that living plants possess electrical potentials and radiate electrostatic fields (Lund, 1929a, 1929b; Rurr, 1945; Dewey, 1956; Maund and Chalmers, 1960). Additional charges are added to the plants by raindrops and by splashings from soil, dust, and insecticidal sprays. The following is a report on experiments to show whether charged surfaces influence insect movements.

The genus Ips in North America contains several groups of closely related species which are at present poorly defined. Morphological characters alone do not provide an adequate basis for deciding whether some of the forms are specifically distinct or represent mere variations which may occur in the same general locality or even in the same brood. The extent of this variation can be determined only by breeding isolated pairs through successive generations combined with biological studies in the field. The present article describes techniques for rearing successive generations of Ips in the laboratory.

When 95% ethanol was sprayed at the rate of approximately 46 ml/m2 of bark surface on the lower 1 or 2 m of standing living spruce trees, Picea engelmannii Parry – P. glauca (Moench) Voss hybrid population, 23 of 47 and 18 of 19 treated trees in two areas received one to many spruce beetle, Dendroctonus rufipennis (Kirby), attacks, whereas only 2 of 63 and 2 of 64 untreated trees, respectively, were attacked. Some of the treated trees were killed by mass attacks of the beetles, but most trees pitched out the attacks. Thus beetle attacks on essentially resistant trees were induced by the ethanol treatment. However, spruce beetles were not attracted by the ethanol treatment.

During studies at Ottawa on the physioloLgy of the onion maggot, Hylemya antigua (Meig.), 29 per cent of 2,320 puparia that had been collected in muck soil at Ste. Clothilde, Que., in the autumn of 1957 were parasitized by the braconid Aphaereta pallipes (Say)2. There are few reports of this insect's parasitizing Diptera in Canada and none on its life-history orbehaviour. Hammond (1932) found it in first-generation puparia of the onion maggot at Ottawa. Wishart (1957) reared it from puparia of the cabbage maggot, Hylewyn brassicae (Bouché), collected from St. Martin and St. Rose, Que. Notes on the biologies of two other species of Aphaereta have been published by Graham-Smith (1919) and Evans (1933), the former on Aphaereta cephalotes (Hal.) and the latter on Aphaereta minuta Nees. Both species are parasites of carrion-infesting Diptera.

The species of the genus Entomacis Foerster in North America north of Mexico are revised. Nineteen species (12 new), including 8 species of the Holarctic-wide perplexa species group, are keyed, described, and figured. These taxa are E. ambigua (Brues), E. apopkaensissp. nov., E. arcticasp. nov., E. cellariasp. nov., E. cepasp. nov., E. eorariasp. nov., E. floridana (Ashmead), E. grandiclavasp. nov., E. longii (Ashmead), E. mellipetiola (Ashmead), E. parambiguasp. nov., and perplexa group members E. californica (Ashmead), E. microbipunctatasp. nov., E. notioxerasp. nov., E. oulasp. nov., E. parvasp. nov., E. perplexa (Haliday), E. sapratasp. nov., and E. subemarginata (Ashmead). Hemilexodes canadensis (Harrington) is synonymized under Entomacis mellipetiola (Ashmead) (syn. nov.). The status of Entomacis latipennis (Ashmead), E. filiformis (Ashmead), and Hemilexis jessei Mann is reviewed. New character complexes, particularly chaetotaxy, are emphasized for Diapriidae species taxonomy.

Monte-Carlo simulation was used to examine the effects of fire return rates on the equilibrium age structure of a one-million-hectare lodgepole pine forest (Pinus contorta var. latifolia Engelm. ex S. Wats.; Pinaceae) and yielded a mosaic of ages over the one million hectares for each fire regime modelled. These mosaics were used to generate mosaics of susceptibility to mountain pine beetle (MPB) (Dendroctonus ponderosae Hopkins, 1902) attack. This susceptibility was related to the age distribution to calculate the mean susceptibility of the forest. Susceptibility maps were produced for two timber supply areas in British Columbia, as well as for the whole of B.C. In addition, we defined a quality, called traversability, that describes the ability of a beetle population to disperse across a landscape according to defined rules of susceptibility and maximum distance for dispersal through unsuitable habitat. Using each of 40 combinations of susceptibility classifications and dispersal limits, the landscape was categorized as traversable or non-traversable. This represents the suitability of a landscape to the unimpeded spread of an incipient beetle population. It was found that (i) long fire cycles yield an age structure highly susceptible to beetle attack; (ii) fire suppression reduces the frequency of fires and yields an age structure highly susceptible to beetle attack; and (iii) harvesting one age class reduces the mean susceptibility to MPB attack, and this reduction decreases with increasing harvest age and increasing fire cycle length. When fires were limited in size to less than 100 ha, the area was always traversable. For larger fires, traversability declined, and for the largest fires (up to one million hectares), the area was often not traversable. Harvesting reduced the mean susceptibility and traversability, often substantially. Traversability was calculated for the whole of B.C. in blocks of about one million hectares using B.C. Ministry of Forests and Range inventory data for the year 2000. The area most traversable was the area around Tweedsmuir Park and the Lakes Timber Supply Area, where most of the present outbreak of MPB is centred. FRAGSTATS patch metrics were calculated for each of the simulations and were related to traversability using discriminant analysis. This analysis was then applied to the B.C. inventory; the concordance was high, with 93.3% of conditions being correctly classified.

Spruce budworm egg deposition spanned 27 days during both 1979 and 1980. The egg deposition curve is essentially a normal bell-shaped distribution with a slight skew to the right. Spruce budworm eggs are most acceptable to T. minutum Riley for successful parasitism during the earlier stages of host–egg development. Parasitism rates at two different temperatures (21 °C and 27 °C) were significantly greater for 1- to 3-day-old eggs than for 6- to 8-day-old spruce budworm eggs. Major reduction in host–egg acceptability occurred after the fifth day at 21 °C and after the 4th day at 27 °C.

This paper describes the seasonal history and habits of three borers of the genus Dioryctria that destroy red pine cones in Ontario. These insects, as a group, generally rank second in importance as cone destroyers to the cone beetle, Conophthorus resinosae Hopk., which was the subject of the first paper in this series (11), and are presented together because of their family relationship and the similarity of their habits.

Bark beetles were trapped for two summers in a mature stand of lodgepole pine, Pinus contorta var. latifolia Engelmann (Pinaceae), infested by mountain pine beetle, Dendroctonus ponderosae Hopkins, near Princeton, British Columbia. Columns of flight-barrier traps were suspended next to uninfested live trees and from dead brood trees containing new adult beetles. The brood trees had been treated in the previous year with mountain pine beetle pheromone bait alone or in combination with Ips pini Say (Coleoptera: Scolytidae) pheromone bait and subsequently killed by mountain pine beetles. A total of 3376 individuals from 30 species of Scolytidae were captured in the traps. Most of the species for which lodgepole pine is a nonhost or occasional host were captured in low numbers (one or two specimens). The most abundant species (> 30 individuals) were D. ponderosae, I. pini, Hylurgops porosus LeConte, Pityogenes knechteli Swaine, and Trypodendron lineatum Olivier. The treatments affected captures of mountain pine beetles and I. pini but only in the year when trees were either unbaited or baited simultaneously for mountain pine beetle and I. pini. There were significant differences among the five most abundant species in the mean heights and mean Julian dates of capture. In addition to host condition requirements, these differences reflected partitioning of the food and habitat resource and competitive interactions among species. There was no interaction between treatment and trap height, indicating that treatment did not affect the height distribution of flying beetles.

Stained serial sections of Gnathotrichus retusus (Lec.) and Gnathotrichus sulcatus (Lec.) males showed an enlargement of the forecoxal cavities to contain fungus cells. No similar enlargement or fungus material was found in these cavities of the females.

Ips calligraphus (Germar) is distributed continentally throughout North America, including Guatemala and British Honduras. It has been collected on only rare occasions in California, primarily in the central Sierra Nevada Mountains. Four generations were observed during 1961 and 1962, and average summer development required about 40 days. All stages except the egg were observed in the winter. The unique gallery system exhibits four to six egg galleries, which range in length from 25.4 to 38.1 cm, and radiate characteristically from a large, irregular, nuptial chamber excavated by the male. At Grass Valley, Cal., this bark beetle was observed breeding predominantly in the thick-barked portions of the lower bole. Its galleries are often intermixed with those of Dendroctonus brevicomis LeConte, I. confusus LeConte, I. latidens LeConte, and Melanophila californica Van Dyke in ponderosa pine. I. confusus was the most abundant species of Ips in all localities where I. calligraphus was found.