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.

The dosage–mortality relationship of a multi-embedded nuclear polyhedrosis virus was determined for each instar of the bertha armyworm by probit analysis of mortality following the ingestion of polyhedral inclusion bodies (PIBs) placed on the surface of an artificial diet. Susceptibility to infection decreased as larvae aged; the median exposure doses (LE50) increased from 18 PIBs/larva for the first larval instar (L1) to 21 × 106 PIBs/larva for half-grown L6. When given equivalent doses, the time for infected insects to die increased with the age of the larvae. Within any given instar the length of time to death shortened with increasing doses. Larvae that survived to become adults showed no signs of infection. There was no evidence that any infected individual could recover from infection. From the data presented, calculations show that maximum production, 2.90 × 109 PIBs/treated insect, is achieved by feeding 10,000–20,000 PIBs/larva to young L5. Larvae dying as L6 have about 40% of their normal dry weight of essential tissue converted to PIBs. Although this MNPV currently would not be cost effective as a spray for protecting crops from bertha armyworm damage, its potential as a biocontrol agent, applied in small amounts at an early stage in bertha armyworm outbreaks, should be evaluated.

A method was developed for the transfer of intact medium-sized Dolichovespula arenaria colonies from their original locations, without damage to the nest and with minimal narcosis of the adult wasp population. The method necessitates a substantial manipulation early in the course of colony development, after which the nest is left to develop normally in situ until it is sufficiently populous to permit tranfer to a new location without intolerable loss of adult insects. We describe also a system for housing vespid colonies following relocation, together with a one-way tunnel system which has proved efficient for the purpose of collecting data on foraging activity.

Thiodicarb and sulprophos were applied to western spruce budworm, Choristoneura occidentalis Freeman, which were infesting small Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco. An aerial spray simulator was used for this application at three dosages. At 105 and 160 g a.i./ha, thiodicarb reduced the number of larvae/100 buds by at least 90%. Sulprophos failed to achieve the target mortality level of 90% or better, even at the highest dosage tested—at 380 g a.i./ha sulprophos reduced the number of larvae/100 buds by 74%. Thiodicarb appears to be the better candidate for future large-scale aerial tests.

Pycnoglypta aptera, a new species of omaliine staphylinid, is described and compared with the Holarctic species Pycnoglypta lurida (Gyllenhal). Scanning electron photomicrographs, line drawings, and a key are provided to distinguish the species.

Yellowjacket colonies were manipulated to test for a possible pheromone emitted by the queen that suppresses worker ovarian development. When queenless and queen-right groups of yellowjacket workers were periodically switched to different sides of a vertically divided nestbox, worker reproduction was partially inhibited. It is suggested that the queen may deposit an inhibitory pheromone on the comb, and workers encounter this queen pheromone during their various colony tasks.

Two bilateral gynandromorphs, specimens of Hydrotaea meteorica (Linn.) (Muscidae) and Siphona hokkaidensis Mesnil (Tachinidae), are described and illustrated. Circumversion of male genital parts is thought to have been prevented by adjacent female genital elements. Study of essentially unrotated male genital halves of these specimens suggests that asymmetry of male sternite 6 in schizophorans results from asymmetrical development (as advocated by Emmert (1972) and Griffiths (1972)) and not as a consequence of slight rotation during circumversion (as advocated by Crampton (1942) and McAlpine (1981)). From study of genital fusion of male and female sclerites across midline, it is further suggested that sternite 6 + 7 in the above species is derived primarily from sternite 6, not from sternites 6 plus 7 as described in Calliphora vicina R.D. by Emmert (1972).

The timing of diapause termination and the thermal characteristics of postdiapause development were compared in six Ontario populations of the spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.). The populations studied were from the major apple growing areas which are located in four climatically different zones. Pupae of all populations collected in the fall and stored under simulated overwintering conditions had terminated diapause by the end of January. Pupae overwintering under natural conditions had also terminated diapause by this time. Significant population differences occurred in the postdiapause developmental threshold (t0) and thermal constant (K). Simulating postdiapause development and emergence of the six populations using the 1981 temperature records from one location resulted in a 9-day difference between the earliest and latest mean emergence times. The implications of these results for pest management are discussed.

The validity of using 40 ± 12 degree-days (DD) above 6.7 °C summed from 1 April for predicting first spring emergence of the spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.), was tested. In Ontario's major apple growing areas from 1978 to 1981, the observed day of first emergence occurred 12–45 days before the predicted day. Reasons for this inaccuracy are discussed.

An alternative method, summing DDs from 1 March above a base temperature of 5.5 °C, was also tested using three methods of computation. The number of DDs accumulated to the day of first emergence and to the day of 50% cumulative emergence varied greatly between years at one location and between locations during one year. This variation is likely due to a variable relationship between air temperature and temperature in the leafminer's habitat. It is suggested that a more accurate predictive index could be developed through an understanding of the relationship between habitat temperature and weather factors such as air temperature, insolation, and snow cover.

The reproductive and demographic statistics of Aphidius smithi Sharma & Subba Rao parasitizing third-instar pea aphids, Acyrthosiphon pisum Harris, were determined under constant laboratory conditions. At host densities of 5, 10, 20, 40, 60 or 100 aphids/day, the parasite lived an average of 7 days at 20.5 °C. At host densities of ≤20 aphids/day, the total number of eggs laid and the total number of hosts attacked were limited by the numbers of hosts available. Fecundity was highest with an average of 870 eggs/female at density 100; the maximum number of eggs laid by any female was 1770. Superparasitism was common at all densities, resulting in up to 84% (at density 5) of all eggs being wasted. The relationship between host density and the number of aphids attacked per egg laid was linear for densities of ≥20 aphids/day. The intrinsic rate of natural increase (r) varied with the host density. It reached maximum value at density 100, calculated as 0.358 female/female/day and assuming an overall sex ratio of 1:1 males:females. Regression equations describing r as a function of host density and parasite sex ratio are provided. It is shown that the potential rate of increase of A. smithi exceeds that of the pea aphid over a broad range of average conditions. The parasite's functional response was convex (Holling type II) and decelerated with increasing density. The intrinsic attack rate (a′) and handling time (Th) were estimated from the functional response curve as a′ = 6.62 days−1 and Th = 0.0033 day (4.7 min). The ‘random parasite’ equation satisfactorily predicted the number of aphids attacked at each density.

Male and female adults of Neomideopsis siuslawensis n. gen., n. sp. are described from Oregon, U.S.A. The genus Neomideopsis is proposed and diagnosed based primarily upon the strikingly autapomorphic presence of 17–23 genital acetabula on each acetabular plate flanking the gonopore. Possible relationships between N. siuslawensis and other Mideopsidae, especially species currently placed in Mideopsis (Nudomideopsis), are discussed.

Chrysops univittatus Macquart females were more abundant in late July and early August in southwestern Quebec. Dry-ice baited canopy trap collections consisted of 55% (n = 177) of the nulliparous and 77% (n = 91) of the parous females. Incidence of nectar feeding, as determined by cold anthrone test, was 73% (n = 244) and 96% (n = 268) of the females contained sperm; no difference was found between parous and nulliparous females. This species is anautogenous, and only one gonotrophic cycle was recorded following ovary dissection. Number of ovarioles was correlated with body size (as determined by wing length) by linear regression analysis.

Placing preserved animals in the wide arm of a fluid-filled U-shaped open tube provides an accurate linear measure of biomass. Changes in fluid level are monitored by projecting an image of the tube into a dissecting microscope equipped with an ocular micrometer. Precision of the calibration curves is equivalent to length–weight regressions. However, only a single curve need be generated to predict wet weight of many taxa. Separate calibration curves are required to predict dry weights of hard- and soft-bodied taxa. The instrument is not suitable for measuring biomass of living individuals.

Larval biomass of the spruce bud worm, Choristoneura fumiferana (Clem.), in balsam fir, Abies balsamea L., stands was significantly reduced following aerial applications of commercial Bacillus thuringiensis (B.t.) (Thuricide 16B®, 24B and 32BX and Dipel 85®). Treatment with Dipel vehicle (Dipel 88® without B.t.) did not affect larval biomass. Biomass reduction following the Thuricide treatment was directly related to feeding activity. These findings support published observations on the long-term effect of B.t. on budworm populations.

Parity of Mansonia perturbans was monitored in Algonquin Park, Ontario from 17 June to 12 August 1981. The first parous individual was recorded on 8 July and parity increased to a plateau of about 60% in late July. The first biparous individual was observed on 30 July and a triparous mosquito was collected on 12 August.

During preoutbreak periods before spruce budworm, Choristoneura fumiferana (Clemens), populations reach epidemic levels, birds can play an important role in regulating budworm abundance (Gage and Miller 1978). All life stages of the spruce budworm are subject to predation by birds, but documentation of predation on budworm eggs is sparse (Hope 1945).

The length of the developmental period from oviposition to adult emergence for nondiapausing individuals of a solitary endophagous braconid, Microctonus vittatae Mues., was usually about 4 wk at 20°C, 70–80% R.H., and a 16h:8h L:D cycle. However, living second and subsequent instar parasite larvae were occasionally found in adults of Phyllotreta cruciferae (Goeze) and Phyllotreta striolata (F.) (Coleoptera: Chrysomelidae) dissected 25–30 days after parasitization. Most of these beetles also contained one or more dead parasite eggs or first-instar larvae, suggesting that superparasitism prolonged development of the single surviving parasite in each host. Therefore, the effect of superparasitism on the parasite's development was investigated by recording the length of the developmental period of M. vittatae in two groups of adult P. cruciferae, one consisting of a majority of superparasitized individuals and the other mostly of hosts with only one immature parasite each.

Research on operational use of Bacillus thuringiensis 3a3b against spruce budworm, Choristoneura fumijerana (Clem.), led to the development of a concentrated B. thuringiensis formulation containing the required potency of 20 B.I.U. of B. thuringiensis in a final volume of 4.7 l./ha (Smirnoff 1978). Aerial operational applications of this formulation were highly effective against the spruce budworm and resulted in acceptable foliage protection (Smirnoff 1979, 1980a). However, it is felt that B. thuringiensis will be used extensively against C. fumiferana only when its cost is lowered to that of chemical insecticides. heref fore, several B. thuringiensis + chitinase formulations were developed leading to an even more concentrated B. thuringiensis formulation, which we call Futura, in which the required 20 B.I.U./ha is applied in a final volume of 2.5 l./ha. We describe the composition of Futura and discuss the bacteriological and physical qualities of the formulations and its efficacy.