The major sex pheromone component from female moths of Retinia metallica (Busck) was identified as Z7,E9-dodecadienyl acetate (Z7,E9-12:Ac) by a combination of electroantennographic (EAG), gas chromatographic (GC), and mass spectrometric analyses. In field tests, males of R. metallica were strongly attracted to Z7,E9-12:Ac. Addition of Z7,Z9-12:Ac, E7,Z9-12:Ac, Z7,E9-dodecadienol (Z7,E9-12:OH), andZ7-dodecenyl acetate (Z7-12:Ac) to Z7,E9-12:Ac did not significantly alter trap catch. However, the addition of E9-dodecenyl acetate (E9-12:Ac) and Z9-12:Ac reduced trap catch. Trap catch was affected by height of placement; traps placed in the upper third of the tree (6 m) caught significantly more males than traps placed at lower heights.

Five new species, Apometriocnemus beringensis, Cricotopus (Cricotopus) bifurcatus, Doithrix dillonae, Hydrobaenus piloculus, and Paratrissocladius lawrencensis, are described. The following new combinations are established: Bryophaenocladius astis (Roback 1951b); Compterosmittia nerius (Curran 1930); Parakiefferiella subaterrima (Malloch 1915); Paratrichocladius nitidus (Malloch 1915); Pseudosmittia nanseni (Kieffer 1926); and Zalutschia sivertseni (Aagard 1979). New genus name synonymies are Maricladius Sublette, 1970 with Parakiefferiella Thienemann, 1936; and Prosmittia Brundin, 1956 with Pseudosmittia Goetghebuer, 1932. New species name synonymies are Spaniotoma (Trichocladius) senex Johannsen, 1937 with Trichocladius nitidellus Malloch, 1915 (= Acricotopus nitidellus); Hydrobaenus traenis Roback, 1957b with Hydrobaenus astis Roback, 1957b (= Bryophaenocladius astis); Compterosmittia clavigera Saether, 1982 with Camptocladius nerius Curran, 1930 (= Compterosmittia nerius); Cricotopus flannagani Saether, 1971 with Cricotopus macraei Saether, 1971; Gymnometriocnemus marionensis Saether, 1969 with Metriocnemus subnudus Edwards, 1929 (= Gymnometriocnemus (Gymnometriocnemus) subnudus); Gymnometriocnemus (Raphidocladius) acigus Saether, 1983 with Metriocnemus brumalis Edwards, 1929 (= Gymnometriocnemus (Raphidocladius) brumalis); Limnophyes spatulosus Saether, 1975 with Limnophyes borealis Goetghebuer, 1933; Limnophyes cristatissimus Saether, 1975 with Camptocladius fumosus Johannsen, 1905 (= Limnophyes fumosus); Limnophyes hudsoni Saether, 1975 with Limnophyes immucronatus Saether, 1969; Hydrobaenus hudsoni Saether, 1977 with Chaetocladius (Parachaetocladius) abnobaeus Wülker, 1959 (= Parachaetocladius abnobaeus); Parakiefferiella torulata Saether, 1969 with Camptocladius subaterrimus Malloch, 1915 (= Parakiefferiella subaterrima); Trichocladius helis Roback, 1957b with Orthocladius nitidus Malloch, 1915 (= Paratrichocladius nitidus); Syncricotopus fontinalis Saether, 1969 with Chironomus rufiventris Meigen, 1830 (= Paratrichocladius rufiventris); Pseudorthocladius (Lordella) comans Saether and Sublette, 1983 with Pseudorthocladius (Lordella) wingoi Saether and Sublette, 1983; Smittia triappendiculata Goetghebuer, 1931 with Camptocladius forcipatus Goetghebuer, 1921 (= Pseudosmittia forcipatus); and Psilometriocnemus cristatus Saether, 1982 with Psilometriocnemus triannulatus Saether, 1969. Major new distribution records are given for 49 species including 8 Nearctic and 32 Canadian. A key to adult males of Nearctic Limnophyes is given.

Field bioassays were used to assess the toxicities of four formulated insecticides to representative stream invertebrates. Toxicities (48-h LC50) after a 1-h application period ranged from 2.0 to 7.1 μg/L for permethrin, 82 to 284 μg/L for fenitrothion, 344 to 1276 μg/L for aminocarb, and 251 to 1504 μg/L for mexacarbate. Invertebrates drifted at concentrations of permethrin greater than 0.5 μg/L, and at concentrations of fenitrothion, aminocarb, and mexacarbate greater than 10 μg/L. An aerial application of 280 g AI/ha fenitrothion with no stream buffer was made to compare bioassay results with impact to aquatic invertebrates under operational spray programs. Concentrations of fenitrothion peaked 30 min after spray at 31.0 μg/L and declined to less than 1.0 μg/L within 14 h. Numbers of drifting invertebrates increased 20-fold 3 h after spray and declined to before-spray numbers within 24 h. Mortalities of caged invertebrates in the stream ranged from 0% for Pycnopsyche sp. to 16% for Simulium venustum (Say). The field bioassay accurately predicted the impacts of fenitrothion on stream invertebrates in this situation.

Induction and aversion-learning are two kinds of behavior modification that depend upon ingestion for their effect. Both have previously been demonstrated in laboratory experiments. The polyphagous, ground dwelling larvae of the arctiid Diacrisia virginica Fabr. have now been shown to experience these two kinds of behavior modification in the field under natural conditions. The adaptive value of aversion-learning is self-evident. The adaptive value of induction is obscure. Evidence is presented here showing that induction overcomes hierarchical specificity before the level of deprivation becomes critical. As a consequence, plants low in the hierarchy of acceptability become fully rather than marginally acceptable, thus minimizing interruptions in feeding. Interruption is known to engender deleterious physiological responses.

A field trial was conducted to evaluate a spunbonded polyester row cover (Reemay) as a means of protecting cauliflower plants from insect pests. Total yield variables (curd weight, size, and color) did not differ significantly between plants under the row covers and those treated with insecticides, although plants under the row covers did produce a greater yield at an early harvest date. Plants in control plots failed to produce any marketable heads, owing to attack by cabbage maggots, Delia radicum (L.). Row covers may be a useful alternative to insecticides for pest control via physical exclusion of the key pest(s) from the crop plant.

A no-choice feeding study was used to evaluate larch casebearer development and survival on eight species of conifer seedlings and two foliar stages of larch from molting to the fourth-instar larvae through adult eclosion. Percentage survival through adult eclosion varied on foliage of western larch (spring—flush stage, 44%; fall—bud set stage, 23%), Douglas-fir (40%), grand fir (26%), Englemann spruce (26%), western white pine (10%), and lodgepole pine (6%). No survival occurred on ponderosa pine or western hemlock. The rate of development differed among conifer seedling species, and between foliar stages of larch.

The genus Cricotopus of the arctic zone of the Nearctic region, represented by 14 species in seven species groups, is reviewed. Descriptive notes on 11 species supplement those given by Hirvenoja (1973), with addition of descriptions of immature stages of C. lestralis (Edwards) and larva of C. tristis Hirvenoja. Two new species names, C. beringensis and C. trilobus, are proposed. New species names synonymies are Chironomus basalis Staeger and Chironomus holmgreni Kieffer with Chironomus tibialis (Meigen) (= C. tibialis). Several undetermined individuals are assigned to the fuscus group. Eleven species are Holarctic in distribution, of which C. bicinctus (Meigen) and C. sylvestris (Fabricius) are circumboreal. Seven species are restricted to the arctic zone, two are wide-ranging in both arctic and temperate zones, and four temperate species barely extend into the arctic zone. Keys to all known life-history stages and some ecological data, primarily of larvae, are given.

Two new species, Tachinus beckeri from northwestern British Columbia and southern Yukon Territory and T. californicus from southern California, are described and their major diagnostic characters illustrated with line drawings and scanning electron photomicrographs. Tachinus jacuticus campbelli is placed in synonymy with T. jacuticus jacuticus and a new subspecies, T. jacuticus ullrichi, from Quebec and Labrador is named. Tachinus thruppi Hatch is removed from synonymy with T. frigidus and considered a valid species. Both T. thruppi and T. frigidus are redescribed and illustrated. A new, revised key to the species of Tachinus is included.New distributional data are presented for 40 species and new or revised distributional maps are presented for 24 species. Changes in classification of Tachinus proposed by Ullrich in his revision of the world species are reviewed and those that are accepted are incorporated into a revised classification of the North American species. These changes are included in a check list of the North and Central American species of the genus.

A simulation model was developed to predict the timing of European corn borer, Ostrinia nubilalis (Hbn.), larval mortality following exposure to Beauveria bassiana (Bals.) Vuillemin conidia. Model response was compared with laboratory and field data collected specifically for model validation. In laboratory validation experiments, four conidial doses of a B. bassiana isolate collected from the People’s Republic of China were applied to European corn borer larvae which were then incubated at fluctuating temperatures. Simulation results compared favorably with fungal development and mycosis under laboratory conditions. Field validation experiments showed that applications of B. bassiana to European corn borer neonates in whorl-stage corn resulted in mortality levels over 60% when conidia and European corn borers were placed on the plants on the same day. When B. bassiana conidia were placed on plants prior to European corn borers, mortality decreased linearly with time. Model predictions of the timing of European corn borer mortality were found to be accurate when B. bassiana conidia were placed on corn plants at the same time or prior to European corn borers. When European corn borers were placed on plants prior to conidia, the model underestimated the time to European corn borer death. Lack of model fit in this situation is thought to be due to delayed host and pathogen interactions on the corn plant rather than poor prediction of the physiological development of the disease.

The Tipulidae occurring in madicolous habitats of eastern North America are briefly discussed. Biological information is given for Dactylolabis montana (Osten Sacken) and D. hudsonica Alexander. A larval key to separate them is provided, as well as descriptions of larvae and pupae for both species.

The abundance levels of eight species of cutworms and army worms were monitored with sex-attractant traps at 81 locations in a 13 000-km2 area of southern Alberta from 1978 to 1983. Year-to-year change in population levels could be consistently detected by monitoring at a relatively small number of locations. For all species, subsets of selected locations along transects, or random subsets of as few as five locations, showed year-to-year fluctuations in mean catch per trap that were similar in pattern to those of the whole monitored area. The results indicate that long-term surveillance monitoring of pest species of cutworms and armyworms to detect year-to-year population changes, and long-term trends, is feasible in terms of both the resource requirements and reliability of the relative population estimates.

The genus Dyschirius includes 56 North American species which are arranged in 13 species groups. Keys are provided for the species groups and the species. Four new species are described: D. sculptus Bousquet (type locality: Pass-a-Grille Beach, Florida); D. ferrugineus Bousquet (type locality: Goose Island State Park, Texas); D. larochellei Bousquet (type locality: 6 mi. S Lake Placid, Florida); and D. comatus Bousquet (type locality: Highlands Hammock, Florida). Six species names are placed in synonymy for the first time. They are (with the junior synonym listed first): D. arizonicus Van Dyke 1943 = D. interior Fall 1922; D. duplicates Fall 1901 = D. affinis Fall 1901; D. desertus Fall 1925 = D. perversus Fall 1922; D. subpunctatus Hatch 1949 = D. sphaericollis (Say 1825); D. basalis LeConte 1857 and D. transmarinus Mannerheim 1853 = D. integer LeConte 1851. The adult and larval character states of the genus are listed and comments are provided for each species group.

In feeding choice tests, first- and second-instar larvae of Calosoma sycophanta L. preferred gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), pupae as prey but third-instar larvae most often consumed caterpillars. All beetle larvae preferred female pupae over male pupae. In non-choice feeding tests, older predator larvae consumed more gypsy moth fifth-instar larvae than the larger sixth-instar larvae, but the total weights of prey eaten in both cases were similar. First-instar larvae of C. sycophanta only partially consumed prey, and caterpillar size did not affect the total numbers eaten. Beetle larvae ate as many female gypsy moth pupae as male pupae, but larger larvae consumed greater weights of the former than of the latter. As a consequence, C. sycophanta larvae fed female pupae were larger than those provided with male pupae. However, for a given increase in size, third-instar larval beetles ingested the same weight of food no matter what the prey size was. Conversely, young beetle larvae seemed to require greater amounts of the body contents of large prey for a given size increase, probably because fluids from large prey were lost during predator attack. The information gained in this study may make it possible to use sizes of field-observed C. sycophanta larvae to predict numbers of prey they have killed.

Stem galls of Diplolepis spinosa (Ashmead), usually found on the endemic rose Rosa blanda Ait., and root galls of D. radicum (Osten Sacken), usually found on the endemic rose R. acicularis Lindl., have become established on the cultivated rose R. rugosa Thunb. in Canada. Adults and galls of D. spinosa and D. radicum are described and compared with those of closely related species. Host records, damage, and distribution of both species are discussed as is the suitability of R. rugosa as a host. It is suggested that galls in urban habitats are being established by adults flying into cities from surrounding patches of endemic roses.

Stems of Canada thistle (Cirsium arvense (L.) Scop.), with galls of Urophora cardui (L.) at various stages of development, were brushed with a concentrated solution of dimefhoate to kill the gall-inducing larvae. Tissues of untreated and treated galls were compared to study the influence of larvae on each phase of gall growth and development. Galls treated in the initiation phase stopped growing. Galls treated in the growth phase grew slightly, primary nutritive tissue was replaced by a thick layer of proliferating callus, and lignified tissue appeared in its normal location. Galls treated in the maturation phase retained the arrangement of their secondary nutritive tissue but it degraded and callus did not develop in the larval chambers. We concluded that active larvae were necessary for normal gall growth and for the retention of primary nutritive cells, but larvae were not necessary for the formation of lignified tissues or for the retention of secondary nutritive cells.

Chironomid stratigraphic analyses of sediment from Hippa Lake, Queen Charlotte Islands, B.C., revealed a fossil chironomid record unlike that reported for deeper lakes of southwestern British Columbia, but similar to an arctic Alaskan sequence. Little evidence of trophic succession or climatic change was noted.

Chironomids, including Corynocera nr. ambigua Zett., rapidly colonized the lake. Because the known adults of Corynocera Zett. are brachypterous, the early arrival of C. nr. ambigua at Hippa Lake suggested either that this species survived in a Queen Charlotte glacial refugium, that chironomids can disperse very rapidly, even without active flight, or the existence of a previously undescribed Corynocera species with well-developed wings.

Elsewhere, fossils of the C. ambigua group are commonly associated with fossil oospores of Chara Valliant and Nitella Agardh. North American records are inconsistent, although similar correlations existed in some coastal lakes of British Columbia.

The efficacy of mixtures of permethrin and Bacillus thuringiensis var. kurstaki Berliner (B.t.), Autographa californica (Speyer) nuclear polyhedrosis virus (ACNPV), or Pieris (= Artogeia) rapae (L.) granulosis virus (PRGV) against the cabbage looper, Trichoplusia ni (Hübner), and the imported cabbageworm, P. rapae, was assessed by field plot tests. Protection of the crop and yield by plots treated with several of the reduced-dosage mixtures were similar to protection and yield by plots treated with permethrin at the full rate, demonstrating a feasible procedure for reducing the amount of chemical insecticide applied without sacrificing protection of the crop. Furthermore, efficacy of the biological component of the mixtures, B.t. or viruses, was frequently enhanced by low concentrations of the chemical component on the mixture.

Glossina palpalis palpalis (Robineau-Desvoidy) and Glossina palpalis gambiensis Vanderplank hybridized readily in the laboratory but hybridized females produced fewer offspring than did females that mated with their own kind. Most hybrid females were fertile when backcrossed to either G. p. palpalis or G. p. gambiensis but almost all hybrid males were sterile. About half of the backcross males were able to fertilize G. p. palpalis and G. p. gambiensis. By using an X chromosome marker gene, tan, evidence was obtained that the X chromosome is involved in hybrid male sterility, either through interaction with the Y chromosome or the autosomes of the other subspecies. There was no evidence for maternally inherited sterility factors of a type that confer unidirectional sterility on hybrid or backcross males.

The fecundity and reproductive longevity of Schizaphis graminum (Rondani) parasitized by Lysiphlebus testaceipes (Cresson) were determined in the laboratory under four temperature regimes. Daily reproduction by S. graminum declined rapidly after parasitization except at a relatively low temperature regime (12–16 °C). The mean progeny production by parasitized aphids of 2.75 ± 0.08 nymphs per parasitized adult was not significantly different than that for unparasitized aphids (2.94 ± 0.23 nymphs) during the period of time equal to the reproductive life of parasitized aphids. Reproductive longevity of parasitized aphids was longest at the lowest temperature (5.67 ± 0.25 days at 12–16 °C). No significant differences were observed in total progeny produced at different temperatures. The number of progeny within parasitized nulliparous adults (3.37 ± 0.33) as determined by dissections was not significantly different from the mean total progeny produced by parasitized aphids. Parasitization thus seems to interfere with oogenesis, but not with embryonic development or progeny deposition.

Studies in eastern Ontario showed that the exotic parasite Dacnusa dryas (Nixon) typically has three generations a year that correspond seasonally to those of its host, the alfalfa blotch leafminer, Agromyza frontella (Rondani). The mature larvae of the third generation enter diapause in September and resume development in the spring. The egg – first instar interval, which occurs within the actively feeding leafminer, developed at rates similar to those of the host larva. The remaining two instars and the pupa, which occur within the host puparium, developed at rates similar to those of the host pupa; in the two non-diapausing generations, the durations of these stages decreased with rise in temperature from 13 to 23 °C. Coincidence of wasp flight and hatch of leafminer eggs was high in all three generations. This host–parasite synchrony results mainly from a sequence of three events during their life cycles: lack of development of the parasite beyond the first instar within the host larva, a temperature-dependent rate of development of the subsequent stages which is similar to that of the host pupa, and different overwintering strategies which result in the parasite emerging later than its host to sustain the relationship. Behavior of the parasite is described in relation to host detection, egg deposition, and reproduction.