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.

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.

The genus Gryon Haliday in North America is revised. Twenty-seven species are recognized, 12 of them new to science: G. aculeator, G. acutiventre, G. atrum, G. chelinideae, G. elatior, G. longipenne, G. obesum, G. radiculare, G. stewarti, G. triangulum, G. vitripenne, and G. xanthosoma. The tribe Gryonini is discussed, and a key to North American genera of the tribe is included. A generic diagnosis of Gryon is given, and seven species-groups are discussed and(or) proposed. A key, diagnoses, relationships, and bionomics of species in North America are given. New terms for additional characters found on the posterior surfaces of the head are defined and figured.

Ten new synonyms are noted in the genera Epistrophe and Syrphus. Lectotypes are designated for Didea alneti (Fallén) and for five species described in Syrphus and now referred, as valid species or as junior synonyms, to Epistrophe or Syrphus. Two new species of Syrphus, intricatus and sonorensis, are described from western North America. Keys to the Nearctic species of Didea, Epistrophe (Epistrophe), and Syrphus, and summaries of species distribution, are presented. Syrphus sexmaculatus (Zetterstedt) is recorded from North America for the first time.

Mosquito eggs were hatched by artificially flooding dry pond beds and estimates of population size were made through larval development for one population of Aedes spencerii, two of A. cataphylla, and three of A. vexans. Overall daily mortality rates were between 8 and 21% and survival to the pupal stage was generally less than 20%, even though water levels were maintained. Mortality appeared to be higher in early larval stages than in later larval stages. Predation was unimportant and survival rate may have depended on food supply or temperature or an interaction between the two. In normal ponds populations often suffer heavy mortality when ponds dry up before development is complete. A. cataphylla, a spring species, developed faster than A. vexans, a summer species, at low temperatures but more slowly at high temperatures.

Pheromone gland rinses of female maple leaf roller moths were analyzed by capillary gas chromatography and found to contain (Z)-11-tetradecenal, (E)-11-tetradecenal, tetradecanal, (Z)-11-tetradecenyl acetate, (E)-11-tetradecenyl acetate, and tetradecyl acetate in the average ratio of 33:20:8:21:17:2 for single female analysis and 31:16:6:16:27:3 for a pooled extract of 55 females. Identity of the tetradecenals, the tetradecenyl and tetradecyl acetates was confirmed by gas chromatography/mass spectrometry. Electroantennogram analysis indicated that (Z)-11-tetradecenal followed by (E)-11-tetradecenal were the most stimulating compounds tested. In field tests, only three components (Z)-11-tetradecenal, (E)-11-tetradecenal and (Z)-11-tetradecenyl acetate, in the microgram ratio of 65:35:10, were necessary for optimum attraction. Another tortricid moth, Archips griseus, was attracted to some of the aldehyde mixtures.

First instar larvae of five spring Aedes spp. mosquitoes survived for at least 25 days beneath moderately thick ice (4.5 cm) in an open field habitat. While survival in the open field was in excess of 85%, larvae inhabiting a nearby deciduous woodland pool suffered 100% mortality within 25 days. Dissolved oxygen levels in the woodland pool fell drastically over the period of ice-cover indicating a trend toward an anaerobic condition which likely contributed to larval mortality.

An analysis of the times to emergence in three sparse populations of Choristoneura spp. in western North America indicates that there was considerable variation in the calculated threshold of development among populations. Also, the number of heat units required to effect the emergence of any specified proportion of the population varied considerably among populations. The pattern of intra-population variation in times to emergence is such that the within-family variation was much larger than the among-family variation in the two populations from areas in which white fir is the only host. In the other population, from an area with a mixed stand of Douglas-fir and white fir, the pattern is reversed. This pattern remains even after an accounting is made for the parental host and larval color morph. It is hypothesized that the pattern of variation in the times to emergence may be due to the presence, in the latter population, of physiological morphs which cannot be recognized either by their appearance or their host of origin. These results have clear implications for pest management procedures which attempt to schedule activities related to the emergence of these insects in the spring.

Contact toxicities of 12 insecticides to adult Leptoglossus corculus (Say) were determined. All insecticides tested were moderately to highly toxic to adult females. Five insecticides—decamethrin, carbofuran, aminocarb, fenvalerate, and bioethanomethrin—were as toxic or more toxic than the standard, azinphosmethyl, at LD90. Decamethrin (LD90 =.06 μg/g body wt.) was 29 times more toxic than azinphosmethyl at LD90. Five insecticides—carbofuran, bioethanomethrin, resmethrin, azinphosmethyl, and chlorpyrifos—were tested on males also. The first three were significantly more toxic to females than males and the latter two were equally toxic to both sexes. All but two insecticides, decamethrin and bioethanomethrin, were equally toxic or more toxic to second-stage nymphs than adult females.

Several chemosterilants have been tested against insects (Borkovec 1966). As a result, a total or partial sterility and decrease in fecundity have been noticed in several insects. Amongst Aphididae, Brevicoryne brassicae L., Myzus persicae Sulzer, Aphis fabae Scop., Macrosiphum euphorbiae Thomas, and Acyrthosiphon pisum (Harris) have been tested to determine the effects of chemosterilants like tepa, thiotepa, and metepa (Bonnemaison 1966; Bhalla and Robinson 1966, 1968; Chawla et al. 1973, 1974; Sharma et al. 1980; Steffan and Stüben 1976). In all previous work, either viviparae or their nymphal instars were the object of chemosterilant treatment and up to 95% reduction in fecundity was observed. Nothing to date has been described on the effect of chemosterilants on the sexuparae or sexuales of Aphididae. To continue with the results obtained by Sharma and Thériault (1980) and Sharma et al. (1980) on the viviparae, this paper describes the effects of 0.5% thiotepa [Tris (1-aziridinyl) phosphine sulphide] on sexuparae of the pea aphid, Acyrthosiphon pisum (Harris), and their progeny.

The blueberry maggot, Rhagoletis mendax Curran, is the most important insect pest of lowbush blueberries. Concern for maggot does not generally result from direct crop losses, but from its presence in harvested fruit which can affect marketability.

Fortunately, the blueberry maggot is not a problem in all lowbush blueberry areas (Wood 1979), but where it does occur, producers are advised to apply one or two sprays annually. General recommendations often result in the unnecessary use of insecticides, especially in years when populations are at low levels because of natural control and management practices. Such misuse could be prevented if monitoring techniques were developed that provide information on seasonal adult prevalence.