Pheromone trapping studies from 1979 to 1981 showed that there were two periods of San Jose scale, Quadraspidiotus perniciosus (Comstock), male flight activity annually in western New York apple orchards. Spring flight, which resulted from overwintering black caps, began at ca. 94–140 degree-days (base 10 °C from 1 March) and occurred during bloom in the apple varieties studied. First generation crawlers emerged at ca. 360 degree-days. Second generation crawlers emerged at ca. 890 degree-days and were active throughout September. Regression analyses showed a logistic relationship between crawler density and fruit infestation, and inverse linear relationships between pheromone trap catches and San Jose scale infestation levels within trees.

Fourteen reciprocal crosses between 11 populations (demes) of troglobitic (obligately cavernicolous) Ptomaphagus beetles were made. Numbers of F1 and F2 larvae and adults are reported. Markedly lower fecundity (but not fertility), viability, and longevity in the hybrids between morphologically distinct populations from Alabama caves indicate substantial reproductive isolation. This and distributional data suggest that the morphologically distinguishable populations are full species.

A bioassay method was developed for estimating persistence and rate of vertical movement of toxic residues of insecticides in soil Laboratory or field microplots of soil 15 to 45 cm deep were enclosed within a metal or plastic framework comprised of 1 or 5 cm sections which could be readily separated for bioassay. Using eggs and larvae of the cabbage maggot, toxic residues of carbofuran could be estimated at concentrations ranging from ca. 0.2 to 30 μg AI/g of dry soil. Higher concentrations were estimated from bioassays on treated soil serially diluted with untreated soil.

Mean daily progeny production by Trichogramma minutum (“Maine strain”) was 15.2 in Choristoneura fumiferana and 10.9 in Sitotroga cerealella eggs. Total progeny production was higher in S. cerealella, but not significantly different from that of C. fumiferana eggs. Significantly more eggs were deposited by T. minutum the first day than in subsequent days regardless of host. We found no significant relationship between progeny produced by females and the day of male death as previously reported. Ratio of females:males decreased significantly with increasing age and opposition activity of the mother. The oviposition period spanned 68% of the female's life span when S. cerealella eggs were available; whereas females spent significantly less time (60%) ovipositing in C. fumiferana eggs.

Laboratory wind tunnel and field observations have demonstrated an important behavioural role of tetradecanal (14:Ald) in the chemical communication system of the spruce budworm, Choristoneura fumiferana (Clemens). A greater number of males initiated upwind flight and continued on to contact the source when 14:Ald was present than with 95/5 E/Z11-tetradecenal (E/Z11-14:Ald) alone. The presence of E11-tetradecen-1-ol acetate (E11-14:Ac) decreased the males' responsiveness to the aldehydes. Its effect appeared to be attenuated, when present at low levels with 95/5 E/Z11-14:Ald, by the presence of 14:Ald, but it is still unclear what effects low levels of E11-14:Ac have on male behaviour.

Larval densities and catch of adult male Choristoneura fumiferana (Clemens) in pheromone-baited covered funnel traps in the same year were highly correlated. Such traps avoid saturation problems associated with conventional sticky traps. Release of marked males resulted in recapture rates of up to 21% in covered funnel traps. The findings suggest that non-saturating pheromone-baited traps could be used to monitor population densities and trends of the spruce budworm.

Culex pipiens entered diapause in early July with more than 90% in diapause by mid-August. Onset of diapause in Culex restuans was in early July with greater than 80% in diapause by late July. The incidence of diapause in C. pipiens increased when larvae were reared at low temperatures or high densities under similar photoperiod conditions. Diapausing adult females of C. pipiens and C. restuans had ratios of follicle:germarium length of less than 2.00:1.00. Ovarioles of recently emerged diapausing C. pipiens developed to the nondiapause stage in 3–4 weeks when held at 25 °C and a photoperiod of 16L:8D. Ovarioles of diapausing C. pipiens in the field did not develop to the nondiapause state before females left their overwintering sites in the spring.

A Latin square design field experiment using treatment, site, and occasion as main effects was set up in spring 1981 to assess the responses of Trypodendron lineatum (Olivier) and Gnathotrichus sulcatus (LeConte) to traps baited with the pheromones lineatin and sulcatol alone and in combination with each other and with ethanol plus α-pinene. Addition of sulcatol to either lineatin or lineatin plus ethanol plus α-pinene resulted in significantly reduced catches of T. lineatum. Addition of ethanol plus α-pinene to sulcatol or lineatin resulted in significantly greater catches of both sexes of G. sulcatus and T. lineatum. These results suggest that separate traps be set out for each species in mass trapping suppression programs in timber processing areas and that ethanol and α-pinene be included with the pheromone to maximize catches of both of these ambrosia beetle species.

Olesicampe geniculatae n. sp., a host-specific palaearctic parasite of the mountain ash sawfly, Pristiphora geniculata Htg., is described and illustrated, together with distinctive features of the immature stages.

Larvae of Neoacarus occidentalis Cook, the first known larval Neoacaridae, are described, and host association and distributional data for the species are provided. A provisional diagnosis for the genus Neoacarus and remarks on possible phylogenetic affinities of Neoacaridae are presented based upon new knowledge of larval morphology.

Larvae of the driedfruit moth, Vitula edmandsae serratilineella Ragonot, enter uncapped tunnels in hives of the alfalfa leafcutter bee, Megachile rotundata F., and eat the pollen and nectar provisions of incomplete cells. Significantly more cocoons are destroyed in hives made of pine nesting material than in those made of polystyrene nesting material. However, significantly more tunnel walls are chewed into and through in the polystyrene than in the wood material. A significant positive relationship exists between the number of moth larvae per hive and the number of bee cells produced in that hive. After hives are removed from the field and placed in storage for the winter, most mature larvae leave the tunnels upon completion of feeding and aggregate in spaces between hives.

Larvae of three species of Proteoteras (P. willingana (Kearfott), P. crescentana Kearfott, and P. aesculana Riley) attack shoots of Manitoba maple (Acer negundo L.) in the Canadian prairies. Larvae of P. willingana and P. crescentana have been confused because both cause gall formations on Manitoba maple and both lack the anal fork that is present in P. aesculana. This paper describes the ultimate larval instar and pupa of P. crescentana. Keys are presented to separate mature larvae, pupae, and adults of the three species.

Prey avoid predators in a wide variety of ways. Grasshoppers of the alpine habitat exhibit predator-avoidance posturing. Furthermore, they show sexual diethism (behavioural differences between sexes) in which the males of Aeropedellus clavatus (Thomas) and Melanoplus marshalli marshalli (Thomas) prance (hop without progression), tending to face the oncoming threat, more so than the females. The latter do not prance to the same extent and more frequently face away from the threat. On the plains, Melanoplus bivitattus (Say) and M. sanguinipes sanguinipes (Fabricius) tend to assume a sideways stance relative to the oncoming threat. Neither plains species exhibits sexual diethism in avoidance behaviour. Prancing occurs in the plains species but, in males, is less frequent than in alpine species. These different predator-avoidance behaviours are apparently related to the need for the grasshoppers to maintain surveillance of potential predators in habitats of different temperature regimes and density and height of cover.

Barrier-pitfall traps and tree bands were used to sample adult carabid beetles in five forest stands of different tree species composition and spruce budworm infestation levels. Twenty genera and 37 species were collected over the 2-year period. Adult carabid populations were highest in the red spruce stand while carabid species diversity was greater in hardwood and fir stands having the most tree species diversity. Potential adult carabid predators of spruce budworm were identified using 5 criteria: number of individuals, habitat preferences, seasonal abundance, size, and food. We conclude that adults of Pterostichus pensylvanicus (Lec.) had the highest potential as predators of spruce budworm followed by Platynus decentis Say, Calosoma frigidum Kby., Pterostichus tristis (Dej.), Cymindis cribricollis Dej., Pterostichus rostratus (Newm.), Calathus ingratus Dej., and Pterostichus adoxus (Say).

The acetone-soluble fraction of phloem tissue samples from 78 lodgepole pines was examined prior to and following artificial inoculation with Europhium clavigerum, a fungus transmitted by the mountain pine beetle. All trees showed quantitative increases in the concentration of extractives within 3 days after treatment. Further increases continued for at least 7 days. By this time qualitative changes in the chemical composition of the host tissue had also occurred.

Trees were defined as resistant or susceptible depending on whether they survived beetle attack under natural conditions. The composition of the acetone-soluble extracts was similar for the constitutive tissue of resistant and susceptible trees, but the total quantity of acetone extractives of reaction tissue was higher in resistant trees.

The ability of trees to respond to fungal inoculation is diminished by mass attack. Trees responded more extensively to inoculation prior to, than during, aggregation under field conditions. An experiment was conducted to simulate this relationship under controlled conditions by examining the effect of multiple fungal inoculations on the production of monoterpenes during the wound response. Individual trees showed a weaker quantitative response on stem sections administered high inoculation densities than on stem sections administered only a single inoculation. Those trees which responded most extensively to a single invasion by the pathogen were more responsive at all inoculum densities.

Some interspecific and interpopulation Lepidoptera and Orthoptera hybrids show a syndrome of developmental abnormalities referred to here as the “sequence effect.” In normal within population broods of Lepidoptera males develop slightly faster than females, but in crosses showing the sequence effect, females in one direction of the cross develop faster and in the reciprocal cross much more slowly than their male siblings. In some cases the environmentally induced diapause of the females may differ strikingly from that of their male siblings. Development rate and diapause in these species appear to be controlled by a sex-linked coadapted gene complex. Expression of the sequence effect may result from a loss of a species- or population-specific balance between regulatory and secretory portions of this complex, resulting in hormonal abnormalities which are more likely to be expressed in the heterogametic sex (females in Lepidoptera, males in Orthoptera).

The rate at which adult house flies, Musca domestica L. developed resistance to permethrin and dichlorvos, in response to two spray regimes, was studied on eight farms near Guelph, Ontario during 1980 and on four of these farms during 1981. These regimes were: continuous reliance on permethrin or permethrin alternated with dichlorvos throughout the spray season. Where sanitation was comparable, resistance to permethrin developed more rapidly in fly populations from the farms on the continuous permethrin regime than on the farm in which permethrin and dichlorvos had been alternated. Resistance to dichlorvos did not decline under the continuous regime while in the alternately selected flies resistance ratios dropped from 11 to 6 after 2 years. Frequent sanitation delayed the development of resistance in a population continuously selected with permethrin. Alternation of dissimilar insecticides appeared to be a viable means of delaying resistance in the field.

The species of the holarctic genus Pyracmon Holmgren are revised. These are presumably all parasites of soil dwelling larvae of Coleoptera. Pyracmon sepiellum (Holmgren) is a parasite of Macropygon piceus LeConte (Dascillidae) and P. ctenicerae n. sp. is a parasite of Ctenicera destructor (Brown) (Elateridae). Seven species are recognized of which two are described as new, namely bucculentum (Holmgren), fumipenne (Zetterstedt), truncicola Thomson, and heteropus (Thomson), all from Europe, nigrifemur n. sp. from Japan, sepiellum (Holmgren), Holarctic, and ctenicerae n. sp. from western North America. The species are described, keyed, and figured based on characters of the adults. The final instar cephalic structures of larvae of sepiellum and ctenicerae are described and figured, these being the first descriptions representing the genus. Relationships of the genus Pyracmon with other members of the subfamily Campopleginae are discussed.

The species Dytiscus vittiger Gyllenhal, 1827 is transferred from the genus Agabus Leach sensu lat. to Ilybius Erichson. The species is recorded from the western arctic regions of North America for the first time. A full description of the species and comparisons with other North American members of the genus are provided.

The seven known species including two new species of Protearomyia are described and keyed: obscura (Walker) and mallochi n. sp., from southern Chile; cordillerensis McAlpine, martinia McAlpine and tricopleura n. sp., from temperate North America, and nigra (Meigen) and greciana McAlpine from Europe. Lectotypes are designated for cordillerensis and greciana. Male and female terminalia are figured where possible; female of martinia and male of trichopleura are unknown.