Forty-three species of Collembola were found, 37 of which were new records for the county.

The reproductive behaviour of the Douglas-fir cone gall midge, Contarinia oregonensis Foote, was studied in the laboratory and in cages outdoors. Adult emergence began in mid-April outdoors and lasted about 2 weeks. Emergence began outdoors at 0600–0700 h Pacific Standard Time, peaked at 1100 h and continued until 1900 h; females dominated emergence early in the day. Mating occurred on or near the duff from which females emerged. Virgin females appeared to “call” males by extending their ovipositors and waving them back and forth, and this behaviour was followed by mating. Laboratory bioassay s using rinses of female abdomens gave further evidence that virgin females produce a sex pheromone. Oviposition behaviour on already infested conelets differed from that on uninfested conelets and suggested the presence of an oviposition deterrent. The mean number of eggs developed by the females was 254, 93% of which were usually laid during the life of the females.

Effects of soil moisture, texture, and temperature on larval and pupal survival and development of the bean leaf beetle, Cerotoma trifurcata (Forster), were investigated in laboratory and greenhouse studies. In both cases, mortality rates were highest during the first instar, decreased during subsequent larval instars, then increased during the pupal stage. Under constant laboratory conditions, survival and adult weights were highest in wet and organic soils and lowest in dry and loamy sand soils. In wet and organic soils, developmental time was shorter than in other soils.

Although survival/plant in the greenhouse was greatest in sandy clay loam, survival/nodule was greatest in organic soil.

These studies, together with oviposition preference, egg survival, and larval movement experiments agree with field observations and provide some explanations for observed patterns of local and regional abundance of the bean leaf beetle in North Carolina.

The posterior midgut of a seed-feeding pentatomid, Euschistus euschistoides (Vollenhoven), contains the proteinases cathepsin B and aminopeptidase. Cadiepsin B hydrolysis of benzoyl-DL-arginine-2-naphthylamide is activated by thiol chemicals and EDTA. Aminopeptidase hydrolysis of leucine-p-nitroanilide is activated by MgCl2 and inhibited by cysteine, glutathione, EDTA, and CaCl2. These results are similar to those obtained for cathepsin B and aminopeptidase from blood-feeding Hemiptera and support the hypothesis that catheptic proteinases are unique to this order.

Fourteen and 16 carbon saturated and monounsaturated aldehydes have been identified as sex pheromone components for the four. species of Heliothis studied to date (Nesbitt et al. 1979; Klun et al. 1979; Teal et al. 1981). With the exception of H. zea (Boddie), the alcohol corresponding to the major aldehyde component, (Z)-1 l-hexadecen- 1-ol (Zl l-16:OH), also has been found in pheromone gland extracts of all species. We report here the identification of Zll-16:OH from pheromone gland extracts of H. zea females and the results of field trapping studies used to assess the behavioral effects of this compound on conspecific males.

The eruption of Mount St. Helens in southwestern Washington on 18 May 1980, ejected tons of volcanic ash that settled over large portions of eastern Washington, northern Idaho, and western Montana. Although most of these areas received only a light dusting, the heaviest deposits in the central path of the ash plume formed a layer of ash 5 to 8 cm thick (Cook et al. 1981). The ash consisted of microscopic, jagged particles that were highly abrasive and easily damaged the epicuticular wax layer of insects, causing desiccation and eventual death (Brown and Hussain 1981). The impact of ash on a variety of agricultural-related insects in the fallout area has been described (Akre et al. 1981; Fye 1983; Howell 1981; Johansen et al. 1981; Klostermeyer et al. 1981). This note reports the effects of ash on small larvae of a major forest defoliator, the Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), as determined in laboratory and field experiments.

A bioassay apparatus using an aquarium filter to maintain water flow and to minimize contamination with black fly larvicides was developed. The apparatus is fairly compact, provides good visibility of and access to the test organisms and is assembled easily from materials readily available. It can be operated in a flow-through or a recirculation mode and can be used to assess pesticide effects on non-target stream invertebrates.

Developmental time of Brevicoryne brassicae (L.) was measured in the laboratory at 8°, 13°, 18°, and 23 °C. Time from birth to adult was 126 degree-days above a threshold of 6.7 °C (°D6.7). Age-specific fecundity and longevity was measured at 13°, 18°, and 23 °C. The temperature thresholds for birth and physiological death rates were not significantly different from 6.7 °C. Fecundity averaged 40.7 nymphs/female and did not vary with temperature or frequency of removal of nymphs. Peak reproduction occurred 75°D6.7 after the molt to adult. Although the time of peak reproduction did not vary as a function of fecundity, height of the reproductive peak and length of the reproductive period did, but not in a 1:1 proportion. Age-specific fecundity was described as a polynomial function of aphid age in °D6.7 and fecundity. Longevity did not vary as a function of fecundity. All aphids survived until after the reproductive peak, so the sum of the age-specific fecundities very nearly equaled the net reproductive rate. Measurements of developmental time, fecundity, and longevity of B. brassicae in the field were 1.3, 0.66, and 1.2 times the respective laboratory value. Consecutive measurements of developmental time and fecundity showed that the former increased and the latter decreased during the season. The consequences of variable developmental time, fecundity, and age-specific reproductive pattern to the quantitative representation of population growth rates are discussed.

Different formulations of temephos were tested against Simulium venustum and S. vittatum larvae at water temperatures of 7 °to 20 °C under simulated stream conditions in the laboratory and the results indicated a significant positive correlation between water temperature and temephos efficacy. Temephos application of up to 5 mg/L/10 min had very little effect on Simulium larvae at 7 ° to 8 °C. Data from the tests indicated that both emulsifiable concentrate and wettable powder formulations have positive temperature coefficients. The WP formulation was 11 times and two EC formulations were 32 times more toxic at 20 °C than at 10 °C. The rate of larval detachment was faster at the higher temperatures but even at 20 °C detachment was not immediate as is common with larvae treated with methoxychlor. Detached larvae did not survive. On the basis of the present laboratory experiments on temperature–efficacy relationships, there are very strong indications that these formulations could be used effectively against black fly larvae only in streams that have water temperatures not less than 18 °to 20 °C.

In 1981 and 1982, the following ant species and numbers were detected preying on pupae of the western spruce budworm, Choristoneura occidentalis Freeman, in eastern Oregon and western Montana: Formica obscuripes Forel, 174; Camponotus modoc Wheeler, 160; C. laevigatus Smith, 53; C. vicinus Mayr, 48; F. podzolica Francoeur, 43; F. accreta Francoeur, 32; F. neorufibarbis Emery, 12; F. lasioides Emery, 1; and Formica sp. (microgyna group). The Camponotus species and F. obscuripes were detected preying on budworm on one-third or more of the trees they foraged.

Counts of four pollinating insect groups were taken in unsprayed forest localities and in areas sprayed with a split application of Sevin-4-oil® (carbaryl) for spruce budworm control. Results indicate a reduction of pollinator populations due to spraying.

Fruit set, measured by fecundity ratios (fruits/flower), was determined for Cornus canadensis L., Maianthemum canadense Desf., Clintonia borealis (Ait.) Raf., and Viburnum cassinoides L. in sprayed and unsprayed areas. Fecundity values for C. canadensis and M. canadense were significantly lower in sprayed than in unsprayed areas. Fruit set of C. borealis was apparently unaffected by carbaryl spraying, but the seed/flower ratio was significantly reduced in the sprayed area. V. cassinoides fecundity values were unaffected by carbaryl application. Reductions in native bee populations probably had the greatest impact on fruit set.

Inclusion of traces of (Z)-11-hexadecenol in synthetic sex lure traps for bertha armyworm moths resulted in diminished trapping; substantial amounts of (Z)-9-hexadecenol or (Z)-11-hexadecenal were also suppressant. Of 22 other oxyolefins tested, (Z)-7-dodecenyl acetate acted in conjunction with the bertha lure components to attract Euagrotis tepperi (Walker) to traps, and (Z)-7-tetradecenyl acetate similarly to attract Lacinipolia vicina (Grote). No tested additive improved either the potency or the specificity of the original bertha blend.

Peanuts, Arachis hypogaea L., have been grown experimentally in Ontario since 1970, with the ultimate objective of commercial production. The pests of this new Canadian crop have been surveyed and the most important one has been identified as the potato leafhopper, Empoasca fabae (Harris) (Ellis and Roy 1979). This pest is native to North America and disperses into Ontario from the south in early June; it attacks a number of crops including potatoes, alfalfa, beans, and peanuts. Feeding by E. fabae interferes with translocation and results in yellowing of the tips of peanut leaves, followed by necrosis, a condition called hopper bum. Reported here are experiments on the injury of this pest to peanuts in 0ntarioT

The larva of Anaquedius vernix (LeConte) is a typical quediine larva but has many distinctive morphological characteristics: tibial comb on the whole length of front tibia, not only on the apical part as in other quediine larvae; tubular organ of the third segment of the maxillary palp at the apex of the segment rather than at the base; pygopod and anal diverticula elongated and well developed, a condition probably related to the almost aquatic life habits of the larva.

The female-produced sex pheromone Cheimophila salicella (Hbn.) was found to be a mixture of E-11-tetradecenyl acetate, E-11-tetradecen-1-ol, tetradecyl acetate and E-11-tetradecenal, as determined by chemical analyses and field-trapping results. Capillary gas-liquid chromatography of individual female tip washes indicated relative ratios of 100:15:10:2. Field-trapping experiments showed the E-11 acetate to be essential and the E-11 aldehyde to be a powerful synergist for trapping of male moths.

En 1980, en faisant l'inventaire des espèces de moustiques de la péninsule de Shippagan au Nouveau-Brunswick, nous avons capturé deux espèces nouvelles pour la province; les dates et les milieux de capture sont précisés. L'identification des culicides s'est faite à l'aide de la clé de Wood et al. (1979). La Flore Laurentienne de Marie-Victorin (1964) a été utiliste pour l'identification et la nomenclature des plantes citées. Les spécimens larvaires ont été prélevés à l'aide d'un filet de type Langeron d'un diamètre de 20 cm, avec lequel une distance prédéterminée a été parcourue. Les larves ainsi prélevées furent comptées en laboratoire et les résultats exprimés en nombre de larves par m3 (larves/m3).

Two-day-old females of Compsilura concinnata (Meigen) were exposed to hosts for several days after which their host-related behavior was observed. Parasites retained their preference for gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), larvae over greater wax moth larvae, Galleria mellonella (L.) (Lepidoptera: Pyralidae), whether conditioned to gypsy moths, wax moths, or no hosts. However, parasites conditioned to gypsy moth larvae examined and attacked hosts less frequently than those conditioned to wax moths or to no hosts. By exposing female flies to gypsy moth larvae for short times before tests and by dissecting them it was found that the number of progeny a female was capable of producing was not closely related to subsequent levels of parasite activity. Thus the activity differences appear to be behavioral rather than physiological in origin. The explanation appears to be that C. concinnata is unusually active when it first encounters a preferred host such as the gypsy moth. The invariance of the preference for gypsy moth larvae despite the exposure history of adult females means that C. concinnata probably could be reared on wax moths in the laboratory without concern that newly-emerged parasites might contact wax moths. They would still successfully attack gypsy moths in the field.

Developmental time, fecundity, adult weight, numbers, and age distribution of Brevicoryne brassicae (L.) and leaf area and plant quality of Maris Kestrel kale, Brassica oleracea L., were determined at three aphid densities and two watering rates in a factorial field-cage experiment. The watering treatment had no effect on the aphid or plant response variates. The aphid density treatment significantly affected final aphid numbers (low < medium = high density), leaf area (high < low = medium density), average adult weight measured at the end of the experiment (high < low < medium density), and weight of the adults in the developmental time measurement (high < low = medium density). The results suggested a strong aphid–plant interaction, but at densities which rarely occur in the field. Leaf water/dry weight was used to assess plant quality, but it was not a good predictor of any of the aphid response variates. Developmental time decreased, and fecundity increased as adult aphid weight increased. Production of fourth-instar apterae decreased logarithmically as aphid density increased.

Twig-feeding injuries by S. multistriatus in juvenile white (or American) elms occurred primarily (61%) in the upper 1/3 of the crowns. Preferred feeding sites were crotches formed by the previous year's and current year's twig growth (both spring and summer) and by leaf petioles from current year's twig growth (summer only). An index of twig feeding appeared to reflect S. multistriatus population trends and was closely correlated with Dutch elm disease rates in Syracuse, N.Y., from 1978 to 1982. Twig-feeding indices and catches on sticky traps baited with S. multistriatus pheromone were generally correlated, but disparate when competing natural pheromone sources were abundant. Twig sampling indicated that S. multistriatus populations and disease rates were reduced by mass-trapping and trap-tree techniques. The twig-sampling method presented appears to be useful in predicting Dutch elm disease rates and assessing the effectiveness of measures to control its beetle vector.

Since 1978 several experiments with aqueous formulations of acephate have demonstrated its potential as an effective and economical control agent for grasshoppers on rangeland (Onsager and Mazuranich 1979; Foster et al. 1981a,b). While it has been generally accepted that grasshopper mortality arises primarily from the ingestion of acephate (Chevron Chemical Co., unpub. data), the extent of the mortality attributable to direct deposition of the spray on the insect or ingestion of the spray remains undefined. The following experiment was conducted to determine grasshopper mortality levels for the methods of exposure (ingestion of sprayed vegetation, direct deposition of the spray on the insect, and a combination of ingestion and direct deposition) which result from an aerial treatment of rangeland with acephate. Any mortality attributable to contact between the insect and sprayed vegetation or ground was not determined because of difficulties in preventing the insects from feeding while being exposed to sprayed vegetation. Studies with malathion, another organophosphate used for grasshopper control, showed that sprayed soil contributed minimally to the total mortality of grasshoppers (Pfadt et al. 1970).