Continuous-flow laboratory bioassays were used to assess the acute toxicities of four formulated insecticides to representative stream invertebrates. Toxicities (48-h LC50) ranged from 3.2 to 7.4 μg/L for permethrin, from 39 to 269 μg/L for fenitrothion, from 478 to 2863 μg/L for aminocarb, and from 99 to 492 μg/L for mexacarbate. Slopes of the probit lines were similar for acetylcholinesterase inhibitors (fenitrothion, aminocarb, and mexacarbate), but slightly lower for permethrin. All test species responded to all of the insecticides at concentrations of 0.25 μg/L for permethrin, 10 μg/L for fenithrothion, and 25 μg/L for aminocarb and mexacarbate by drifting in the test chambers.

Lygromma anops sp. nov. (Gnaphosidae, Araneae) is described from lava tubes on Isla Santa Cruz, Galápagos, Ecuador. The species appears to have no known close relatives in the Galápagos Islands or on the South American mainland.

The number of instars of larvae of the alfalfa leafcutter bee, Megachile rotundata (F.), was determined by direct observation, frequency distribution plots, and linear regression of head-capsule measurements. For all three methods, developmental polymorphism was observed; larvae were grouped according to the number of instars. The majority of larvae (77%) had four larval instars and the remainder had five. Mortality of bee larvae, apparently a result of physical injury during measurement of head-capsule width, was high but results were based on data for 259 individuals that completed development to the prepupal (= pharate pupa) stage. Direct observation of larval moults was found to be the only accurate method for determining instar designation but analysis of head-capsule width did describe the number of instars present in a population and provided estimates of head-capsule width for each instar. A morphological key for separation among four instars is presented as a practical alternative for instar determination in field studies.

Five formulations of the primary sex pheromone components of the spruce budworm (Choristoneura fumiferana [Clem.]) were evaluated as lures for monitoring spruce budworm populations: Biolures (Consep Membranes Inc.), Luretape plastic flakes (Hercon, Healthchem Corp.), polyethylene vials (International Pheromone Systems), hollow fibers (Albany International), and polyvinyl chloride (PVC) pellets. PVC pellets showed significant loss in attractiveness over the required 6-week period. Also, different batches of PVC pellets had very different rates of pheromone release and attraction; the oldest lures, stored for the longest period, were the most attractive. Luretape caught fewer moths than anticipated from the release-rate data and showed wide variation in catch among individual lures. Fibers were inconsistent. Biolures and polyethylene vials showed the lowest decline in attractiveness over time and the lowest variation in catch among individual lures, but their capture rates were higher than necessary.

The 6th-instar larvae of Noctua pronuba (L.) are described and illustrated. The larvae, although similar to other noctuinae genera, can be distinguished by the hypopharyngeal complex and mandible morphology. Life history notes based on larvae and adults collected in Nova Scotia are also given.

The North American representatives of seven species groups in the genus Pardosa are reviewed and are found to have the following distribution: (1) the atrata group, represented by the widespread nearctic species P. fuscula (Thorell), which may or may not be conspecific with P. atrata (Thorell) of the Palaearctic; (2) the cubana group, represented by P. cubana Bryant of the Caribbean area; (3) the ferruginea group, represented by P. beringianasp.n. from Alaska and Yukon Territory; (4) the moesta group, represented by the widespread nearctic P. moesta Banks; (5) the monticola group, represented by the holarctic P. palustris (Linnaeus); (6) the saltuaria group, represented by the holarctic P. hyperborea (Thorell) and the nearctic P. californica Keyserling; (7) the solituda group, represented by the nearctic P. solituda Levi and Levi, found only in the high Rockies.

Adult males were reared from larvae of the type previously associated with Anepeorus. These adult males key to and fit the description of Heptagenia cruentata Walsh. Because the larvae are very different from those of other Heptagenia species, a new genus, Raptoheptagenia, is proposed for cruentata. Adult males of Raptoheptagenia differ from those of Heptagenia in the anastomosis of two or more crossveins in the stigmatic area of the forewing, and in the subequal lengths of the foretarsus and tibia.

Fifteen species of stoneflies (Plecoptera) were collected in the Lake Athabasca region of northern Saskatchewan. Capnia nearctica Banks is reported for the first time from Saskatchewan, and collection records of Isogenoides frontalis (Newman), Nemoura rickeri Jewett, and Paracapnia angulata Hanson represent significant range extensions. All species collected from lotic habitats have biogeographical affinities with streams from the Southern Boreal Ecoregion, but some species collected from Lake Athabasca have biogeographical affinities with the Southern Boreal Ecoregion and others have affinities with the Tundra.

An overview of data from five research groups participating in a 3-year pilot test on the efficacy of foliar applications of Beauveria bassiana (Balsamo) Vuillemin for control of Colorado potato beetle, Leptinotarsa decemlineata (Say), populations in the northern United States is presented. Four treatments were used at each site: high and low B. bassiana dosages (5 × 1013 colony forming units (CFU) per hectare (ha) and 5 × 1012 CFU/ha), the recommended insecticide for each region, and an untreated check. The primary response variable was potato yield. For analyses considering test sites as replicates, during all 3 years the highest yields were produced in plots treated with insecticides. Within test sites, yields from plots receiving B. bassiana applications were greater than control plot yields in 8 of 24 trials but in only two of these instances, B. bassiana plot yields also did not differ from insecticide plot yields. Evaluating 1983 data from all states together, no differences were found between either high or low B. bassiana treatments and controls. The 1983 study design allowed no plot replication within states. In 1985, an altered plot design providing within-site replication demonstrated increased yield with increased dosage of B. bassiana when initial egg density was used as a covariate.

Potato yields greater than control plot yields were noted with a minimum of 5.39 and 6.62 × 1011 CFU/ha B. bassiana. The lowest B. bassiana concentration producing yields not significantly different from insecticide plot yields was 6.62 × 1012 CFU/ha (Rhode Island, 1984). Defoliation ratings did not differ between B. bassiana treatments and controls in 1984 and 1985, although variability was found between yields.

Pine oil (Norpine-65, Northwest Petrochemicals) was assessed as an oviposition deterrent for gravid female onion maggots, Delia antiqua (Meigen), in two types of laboratory experiments. When given a choice for 24 h between a control onion half treated with hexane and an onion half treated with pine oil in hexane, the females oviposited preferentially on or around the control onion half. In a no-choice experiment the females laid over three times as many eggs on or around solvent control onions as on or around onions treated with 1.0% pine oil. The DC50 (deterrent concentration50) was calculated to be 0.09%. The results suggest that pine oil (or its constituents) may have potential as an oviposition deterrent under field conditions.

The oribatid mite genus Ametroproctus, soil and litter inhabitants in the desert, alpine, and montane regions of western North America, is discussed. Two subgenera are recognized, Ametroproctus s. str. and Coropoculia. Their respective type-species, A. oresbios Higgins and Woolley and C. reticulata Aoki and Fujikawa, are redescribed, and newly discovered immatures of both species are described. Four new species are proposed, A. (Ametroproctus) tuberculosus, A. (A.) aridus, A. (Coropoculia) beringianus, and A. (C.) canningsi. A new generic diagnosis is given, as well as a key to subgenera and species known from North America.

Application of granulosis virus (CPGV) to plots of apple trees reduced deep-entry damage to apples by the codling moth, Cydia pomonella (L.), compared with nontreated apples. However, shallow-entry damage to apples by codling moth was as great, or greater, in virus-treated plots than in nontreated plots. Protection was improved by applying CPGV at least three times during each of the two annual generations of the codling moth compared with less frequent application.

Bioassays showed that activity of deposits of CPGV on apples in the field was reduced to approximately 50% of original activity within 2 days after application and to 17% by the 10th day.

The species of Synophromorpha Ashmead (Hymenoptera: Cynipidae) are reviewed. One new species is described (Synophromorpha kaulbarsi; type locality: Naupan, Puebla, Mexico). The previously described species (S. rubi Weld, S. sylvestris (O.S.), and S. terricola Weld) are redescribed, and a key to species is presented. All species are illustrated for the first time. Synophromorpha sylvestris is designated type-species for the genus and a lectotype is chosen. Hypotheses on the phylogenetic relationships between the species of Synophromorpha are presented.

A description is given for the male, female, and larva of Farula praelonga sp. nov. and for the female and larva of Neothremma genella Denning. Farula praelonga sp. nov. is distinctive in having an exceptionally long internal branch of segment X. The female of Neothremma genella is the only female yet known in that genus to have greatly reduced ventrolateral lobes of sternum IX. Modifications are made to the keys previously published for adults of Farula and Neothremma to incorporate this new information. These two species occur together in abundance; they are univoltine and have emergence periods 6 months apart.

The primary follicles of all 291 laboratory-reared Simulium arcticum Malloch females provided with only sucrose and water did not develop beyond stage II. This was true for flies derived from field-collected eggs, larvae, or pupae, and for laboratory-reared larvae that received either standard, concentrated, or unsupplemented river water diets. Conversely, all 59 females that digested a meal of cattle blood had follicles at stage IV by 85 h and stage V (mature eggs) by 109 h post-engorgement. Simulium arcticum populations from the Athabasca and Crowsnest River were thus characterized by obligate anautogeny and gonotrophic concordance. Most non-blood-fed females were dissected and examined when 4–19 days old. The presence or absence of a meconium, quantity of fat body, and other internal features were compared in young and old non-blood-fed females.

A distributed delay age structure model is presented for plants and insects that describes the dynamics of per capita energy (dry matter) acquisition and allocation patterns, and the within-organism subunit (e.g. leaves, fruit, ova) number dynamics that occur during growth, reproduction, and development. Four species of plants (common bean, cassava, cotton, and tomato) and two species of insects (pea aphid and a ladybird beetle) are modeled. A common acquisition (i.e. functional response) submodel is used to estimate the daily photosynthetic rates in plants and consumption rates in pea aphid and the ladybird beetle. The focus of this work is to capture the essence of the common attributes between trophic levels across this wide range of taxa. The models are compared with field or laboratory data. A hypothesis is proposed for the observed patterns of reproduction in pea aphid and in a ladybird beetle.

The dosage of carbofuran as a bait required to reduce third-instar grasshopper populations to non-economic levels (5–10 grasshoppers per square metre in short mixed grass hay pasture) was considerably lower than the recommended rate for spray application. The results from 2 years’ field trials showed that 35.0 g active ingredient per hectare as a bait would reduce grasshopper populations by about 70%, 3 days after application.

The role of starvation, the occurrence of mating, and delays and the onset of mating on the retention of eggs by the gypsy moth, Lymantria dispar (L.), were evaluated. The mating status of female gypsy moths did influence egg retention.

Mating delays did not affect egg retention. Differences in the number of females retaining some eggs were found among females whose larvae had been reared on different host plants. The amount of food consumed had a significant effect on egg retention. Partial starvation had an impact on egg retention and on larval and pupal development, pupal size, and total egg production. The greater the starvation the greater the egg retention. The ecological implications of these results are discussed.

A key to the species of Hymenoptera that parasitize insects feeding on sunflower seed heads is presented. The data base for this work is from rearings done in mid-western Canada but the key should be reliable throughout North America. A discussion of each parasitoid, giving host records, distribution, references, and a morphological diagnosis, is presented. Finally, a list of all of the species of parasitic Hymenoptera associated with sunflower in North America is given including important references.

Overwintered adults of Dendroctonus simplex LeConte emerged in May and June. One generation and two broods were produced in both 1983 and 1984. Females initiated attacks and males arrived within 2 days. One to four pairs of beetles used each entrance hole but each pair constructed a separate egg gallery.

Emergence, host attack, and re-emergence occurred between 1030 and 1700 hours NDT and at mean air temperatures above 4°C. Peaks of attack, which reflect flight peaks, occurred at temperatures above 10°C. About 90% of all parents re-emerged from first brood trees and 61% from second brood trees.

Only adults overwintered. Freezing temperatures caused complete mortality of immature stages. Thirty-five percent of new brood adults emerged in the fall and re-entered galleries at the base of trees for hibernation. Adult tolerance to cold increased from early fall to mid-winter.