Douglas-fir tussock moth cocoons were collected and their distribution recorded by crown level on white fir, Abies concolor, in northeastern California. Nine trees were sampled in two defoliation classes, light (20–30% defoliated) and moderate to heavy (50–80% defoliated). Cocoons were more abundant in the lower crown levels as defoliation became greater. The proportion of female cocoons increased toward the lower levels of the crown. An overall sex ratio of 1.2♂:1.0♀ was recorded. Significantly more male cocoons were parasitized than female. A list of the natural enemies of the tussock moth from the study area is given.

Pear psylla, Psylla pyricola Foerster, had three generations in 1968 in Nova Scotia. Laboratory studies indicated that overwintering females require mating in the spring to produce fertile eggs. The adults started activity by the end of March, Psylla eggs and nymphs were preyed on by eight predacious species in the laboratory. These and the larvae of another six predacious species were associated with psylla in the field. A few psylla nymphs were parasitized by Trechnites insidiosus (Crawford). Psylla adults fly or are carried with the prevailing winds and a significant percentage occur above the tops of the trees.

Only one species of Anoetidae was previously recorded associated with North American Scolytidae. Five new species of Anoetus and one new species of Bonomoia associated with North American bark beetles are described. Two nomen novum (due to homonymy) in the genus Anoetus are proposed. Anoetus varia is distinguished from A. gordius, a European species restricted to Ips laricis. Anoetus varia is recorded from 17 scolytids infesting 10 conifer species from 14 states and provinces. An annotated list, with new nomenclatorial combinations in many cases, of the 13 anoetids recorded associated with scolytids in the old world is given. Histiostoma is synonymized under Anoetus.

The generic concept of Heterotarsonemus Smiley is reviewed and redefined. The type-species, H. lindquisti Smiley, is redescribed and illustrated along with a new species, H. bicornis; the only described European species, H. coleopterorum Schaarschmidt new combination, is compared with the above two nearctic species. The known species of this genus are associates of bark beetles in conifers.

The generic limits of Paragnorimus Becker are redefined and two new species, P. sambucus from Chiapas, Mexico, and P. guatemalensis from Volcan Acatenango, Guatemala, are described.

The seven nominal species of Lonchaeidae described by Kertész, namely, Lamprolonchaea metatarsata (Kertész), Lonchaea megacera Kertész, Silba albisquama (Kertész), Silba biroi (Kertész), Silba pollinosa (Kertész), Silba excisa (Kertész), and Lonchaea cyaneonitens Kertész are redescribed and figured. Lectotypes are designated for metatarsata, albisquama, pollinosa, and excisa; biroi is sunk as a synonym of albisquama. Figures of the male genitalia of Lonchaea dasyscutella McAlpine, related to Lonchaea megacera, and of Silba imitata McAlpine and Silba emulata McAlpine, two species that are closely related to Silba albisquama, are provided.

Samples were taken weekly from 11 June to 1 October 1968 from brown slime fluxes occurring on trees (mostly elms) in Rockport, Mass., and in central and eastern areas of Connecticut and held in the laboratory for the emergence of adult insects.The most common emergents were Aulacigaster leucopeza (Meigen) and its parasite, Aphaereta colei Marsh, Mycetobia divergens (Walker), and Dasyhelea oppressa Thomsen. The only drosophilid reared from brown slime flux was Drosophila robusta Sturtevant, a species that was not particularly common.A comparison of the brown flux fauna of Great Britain with that of New England shows that some cosmopolitan species occur in flux in both countries. Species whose distribution is limited to only one of the countries are represented in the other country by closely related species (ecological homologues).The relationship between climatological factors and the fluxing condition of trees is discussed. The factor considered most important in continuing the fluxing state is rainfall during the late summer months.

Rearing of Diabrotica balteata LeConte is possible throughout the year at temperatures between 10° and 30 °C. Adults feed on a very large variety of host plants. Good edibility combined with pronounced oviposition and egg viability are found in Cucurbitaceae, Leguminosae, Rosaceae, and Cruciferae. However, cases of good edibility with no oviposition are also established in several families. Optimal adult longevity lies between 17° and 24 °C and oviposition indicates two high peaks within the female life span.Temperatures below 0 °C are detrimental to all stages and those between 0° and 4 °C mainly to larval and pupal stages. No diapause is found in any stage and this explains the limited distribution within warmer regions of the Americas. Precautions not to introduce this species into other continents should be taken.

Wood and bark extracts from balsam fir, red cedar, spruce, hemlock, and pine were assayed for juvenile hormone-mimicking activity on pupae of the wax moth. All the extracts showed noticeable activity; the wood extracts were generally more active than the bark extracts. The results suggest that the purification of the extracts from these conifers might lead to the isolation of compounds with high hormone-mimicking potential.

When given a choice of large, unparasitised sixth-instar larvae of the European pine shoot moth, Rhyacionia buoliana, and small sixth instars containing developing Orgilus obscurator, Hyssopus thymus selected the former. This discrimination does not exist when the host larvae are in the third or fourth instars. The size of the contained O. obscurator larva is related to this change in behaviour. H. thymus shows no cleptoparasitic tendencies and is recommended as a safe candidate for introduction where O. obscurator exists.

Pleolophus basizonus (Gravenhorst) is a parasitoid from Europe introduced in Canada and liberated between 1939 and 1949 to supplement natural mortality factors of sawfly populations. Three recoveries reported in the literature show that the parasitoid has dispersed 81 km at 4.3 km per year in Ontario, between 109 and 161 km at 4.5 and 5.6 km per year in Quebec, and 172 km at 8.6 km per year in Michigan. Dispersal occurs by walking, possibly by short flights and by water while the parasitoid is within the host cocoon. Female parasitoids do not fly unless disturbed and dispersal by water cannot account for their movement in Quebec. In observation trays, the mean rate of travel on the ground by female parasitoids was 20.9 cm per minute. This speed is sufficient to account for the rates of dispersal recorded in the field. The parasitoid was present in every jack pine stand sampled between 1965 and 1968 in the western part of the St. Maurice River watershed in Quebec. The most abundant host was Neodiprion swainei Middleton. Absolute population estimates indicate that the parasitoid responds positively to host density and that it is an important addition to the native parasitoid complex.

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.

Haemocytes of the Pacific beetle cockroach, Diploptera punctata (Esch.), are described and figured as they appear in vivo and in stained blood films. Although the haemocyte complex in this species is comprised of the same main categories as found commonly in other cockroaches, it is somewhat unusual due to morphological specialization among one category, the granular haemocytes. Most of the cells in this category are similar to those in other species, but some contain distinctive vesicles of mainly proteinaceous material, some are ovoid and contain spherule-size granules, and some are large, fusiform cells that are actively amoeboid in vivo. The other main categories, prohaemocytes, plasmatocytes, and spherule cells are fairly typical.

Larvae are reared on a synthetic diet in 1 oz. ribbed plastic cups. To eliminate the task of placing individual larvae on food, small gauze patches containing 25–40 larvae are placed in the cups prior to emergence from hibernacula. Larvae establish feeding sites between the ribs and are relatively undisturbed by others in the cup until the fifth instar. For maintenance of rearing stock the number of larvae is reduced to six to eight per cup, and they are allowed to pupate in the cups. Up to 100 pairs of pupae are placed in screened cages for adult emergence, mating, and oviposition. When the adults emerge balsam fir foliage is introduced and most of the eggs are deposited on the needles. Needles or twigs with egg clusters are transferred to large dishes the inside of which is painted black. The dish is tightly sealed with parafilm to which small gauze patches are attached and then placed under artificial lighting. The newly-hatched larvae are attracted toward the light and spin hibernacula in the gauze. The parafilm and gauze are sealed in plastic bags for cold storage treatment. By this system up to 10,000 larvae per week are easily produced.A discussion on the selection of rearing stock, rearing conditions, rearing containers, and the use of anti-fungal agents is included in the report.

Utilizing the knowledge of their direct effects, the materials ryania, carbaryl, and Animert V-101 applied to a uniformly distributed population of the European red mite, Panonychus ulmi (Koch), altered the populations in plots in an apple orchard. Trends after treatment in both host mite and predator populations were assessed. Supplementary applications of the acaricides Animert V-101 or dicofol directed against certain generations of P. ulmi controlled outbreaks and altered the faunal levels during the following season. Ryania was largely innocuous to most species of predators with the exception of Atractotomus mali (Meyer) and Diaphnocoris spp., carbaryl was detrimental to most predacious species, and Animert V-101, while selectively toxic to phytophagous mites, was innocuous to all predacious insects and Typhlodromus pyri Scheuten.Phytophagous mite populations may be altered to almost prescribed levels with pesticides when the predator populations are known. This allows selective chemicals to be used to complement the predator effect and maintain red mites below the threshold of damage.

Experiments were carried out on excised leaves to determine the form of the functional response curve of the phytoseiid predators Amblyseius largoensis (Muma), A. concordis (Chant), and Typhlodromus floridanus (Muma), to increases in density of the prey, Oligonychus punicae (Hirst). The curve for each species was curvilinear to a plateau from prey densities of 1 to 70/arena, the average number killed/24 hours at the plateau being 8.5/female for A. largoensis, 5.5/female for A. concordis, and 2.0/female for T. floridanus. From prey densities of 70–300/arena, there was an accelerated rise to another plateau, in which the average number of prey killed in a 24 hour period was double that of the first plateau.Detailed analysis of A. largoensis at a density of 200 prey/arena showed the effect to be due to a stimulation–interference component, which resulted in the predator killing several prey in close succession because of increased prey contact, and because total utilization of each was minimal. During a 1 hour period, A. largoensis captured an average of 1.25 prey/predator at a prey density of 35/arena, while at a prey density of 200/arena, 3.87 prey/predator were captured. More than four times longer was spent feeding on the first prey at a density of 35 than at a density of 200 prey/arena. During the time that the predator was hungry, it was stimulated to capture and kill interfering prey that bumped into it.The functional response curve of the three predators increased in magnitude when waterproofed paper arenas were used. Four possible reasons for this increase are discussed: reduced number of prey eggs for consumption by T. floridanus; lack of webbing, which interferes with searching; increased prey activity; and dehydration of prey, affecting their relative palatability to the predator.

Campoletis pyralidis, a new species of ichneumon fly parasite on several species of Pyralidae in Canada, is described.

Four new species of Trigonotylus Fieber are described from North America: brooksi from British Columbia and Saskatchewan; flavicornis from Saskatchewan and Manitoba; canadensis from Alberta, Saskatchewan, and Manitoba; and antennatus from British Columbia, Saskatchewan, Manitoba, and California. The genitalia of the species are illustrated.

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.

The type, number, and distribution of the antennal sense organs of female Culex territans Walker and Culex restuans (Theo.) were determined and compared to similar data on Culex pipiens L., Culex fatigans Wiedemann, and Culex tarsalis Coquillett. All types of sense organs have similar distribution patterns on the five species, but large differences in number occur. These differences are discussed with regard to the host preference of the mosquitoes.