Effects of an operational application of Dimilin® on non-target insects were evaluated in eastern West Virginia in 1988 and 1989. Dimilin was applied in 1988 (70,75 g AI per ha). Insects were collected by light-traps at seven pairs of Dimilin-treated and control sites. Lepidoptera experienced the greatest impact, displaying reduced abundance and species richness at treated sites. No effects were observed among Coleoptera, Diptera, or Hymenoptera.

Pullimosina (Dahlimosina) bladesi sp.nov., an atypical, superficially Pullimosina (Pullimosina)-like species, is described from fens in Ontario and Alberta. Subgeneric classification of the genus Pullimosina is discussed, concluding that the subgenera of Pullimosina can be defined only on characters of the male and female terminalia.

Vesicas of the following tortricid and other small lepidopterous species are described and illustrated: Tortricidae: Orthotaenia undulana (Denis and Schiffermüller), Apotomisfrigidana (Packard), Olethreutes appendiced (Zeller), Evora hemidesma (Zeller), Epinotia nanana (Treitschke), Corticivora clarki Clarke, Atchips packardiana (Fernald), Pandemis limitata (Robinson), and Aethes rutilana (Hübner); Oecophoridae: Psilocorsis quercicella Clemens; Gelechiidae: Dichomeris flavocostella (Clemens); and Nepticulidae: Obrussa ochrefasciella (Chambers).The injection and chemical induction techniques of eversion of vesicas of tortricid moths and other Lepidoptera are described.

Sex pheromone-mediated mating disruption was used to control the grape berry moth, Endopiza viteana (Clemens) (Lepidoptera: Tortricidae), at two farms in the Niagara peninsula, Ontario, during three consecutive growing seasons, 1989 through 1991, to determine if earlier observed between-generation increases in the percentage of infested grape clusters would continue between growing seasons. The relative performance of the pheromone treatment was assessed by comparing the percentage of infested clusters in the pheromone-treated plot with the percentage of infested clusters in an adjacent, insecticide-treated plot. Although the percentage of infested clusters increased from 1.7- to 56.5-fold between successive generations in the pheromone-treated plots, there was no indication that the level of infestation at harvest affected the level of infestation the following spring. At one farm, the percentage of infested clusters was greater in the pheromone-treated than in the insecticide-treated plot during 1989, but during 1990 and 1991, the level of infestation was similar in the two plots. At the other farm, the level of infestation was from 2- to 3-fold greater in the insecticide-treated than in the pheromone-treated plot.

Two species of cone maggots, Strobilomyia Michelsen, are known to attack seed cones of spruces in North America. Seed cones of black, red, and white spruce from Newfoundland to Alberta were collected to determine the number of host species and the distribution of these maggots. Strobilomyia appalachensis Michelsen was obtained only from seed cones of black and red spruce, whereas S. neanthracina Michelsen was obtained only from white spruce seed cones. Our observations represent the first record of S. appalachensis in Canada. We conclude that, like S. neanthracina, S. appalachensis has a transcontinental distribution, but exploits different hosts, namely black and red spruce. We also observed that S. appalachensis was capable of extended diapause.

The life history of Cricotopus myriophylli Oliver is described from both field observations and laboratory rearing of field-collected larvae. The species appears to be univoltine with four larval instars and has a sex ratio of ca. 2:1, males to females. Emergence begins in late May in British Columbia and continues until mid-September, with first-instar larvae present in the field from mid-June to mid-August. Water temperature does not appear to influence the rate of emergence. In the laboratory at 21 °C, larvae complete each of the third and fourth instars in 10–14 days. Cricotopus myriophylli overwinters primarily in the third larval instar, although second and fourth instars were also recovered in field-collected samples. First-instar larvae and eggs were not recovered from winter samples. This species does not appear to undergo a true diapause.

The 48-h toxicities of freshly deposited residues of 28 insecticides against Aphytis melinus DeBach and Rhizobius lophanthae (Blaisd.) were evaluated at various rates. Rates as high as 4-fold the recommended field rate of several materials (formulated plant alkaloids, amitraz, formulated Bacillus thuringiensis Berliner endotoxin or exotoxin, and cryolite) revealed little mortality to either species. Concentration–mortality regressions were quantified for the remaining materials, which included five carbamates, a macrocyclic lactone, eight organophosphates, and four pyrethroids. Of these, pyrethroids in general were most toxic, followed by carbamates, and then organophosphates, to both species. Most materials tested were more toxic to A. melinus than to R. lophanthae.

Infrared thermometry was investigated as a diagnostic tool to detect root injury in corn caused by feeding of the western corn rootworm, Diabrotica virgifera virgifera LeConte. Plots were infested with 50–1000 eggs per plant, and the study was conducted over 2 years. Differences (P < 0.05) in canopy temperatures were detected in severely infested plots in 6 out of 13 days and 7 out of 11 days on which measurements were made during the period of feeding by rootworm larvae in 1989 and 1990, respectively. Temperature differences between the air and leaves from infested plants were never greater than 3.5 °C and usually occurred within ± 1 °C. Feeding by rootworm larvae at infestation levels of less than 200 eggs per plant could not be detected with infrared thermometry. Above densities of 200 eggs per plant, increases in canopy temperatures corresponded with increases in the level of infestation with rootworm eggs, and with reduced plant height, and lower grain yield. Losses in grain yield due to rootworm infestation were manifested through smaller cobs and fewer seeds per cob. Kernel weight was not affected by rootworm feeding. Crop maturity was delayed at infestation levels of 1000 eggs per plant.Elevated canopy temperatures induced by rootworm feeding were detected through infrared thermometry in commercial corn fields, however differences (P < 0.05) in canopy temperatures were noted only after 10 July. Although these data show that elevated canopy temperatures induced by rootworm feeding can be detected with infrared thermometry, some inconsistency in results was observed. Various reasons for why the technique was not more reliable are discussed.

Published studies have shown inconsistent effects of proteinaceous bait sprays against apple maggot flies, Rhagoletis pomonella (Walsh). Explanations of inconsistency could involve the presence of natural food such as bird droppings competing with bait sprays for attraction of flies. Under field, semi-field, or laboratory conditions, we found that: (1) aqueous solutions of 10% proteinaceous bait (Nulure) were significantly more attractive than water to protein-denied but not to protein-provided apple maggot flies; (2) addition of 2% toxicant (malathion 50 EC) did not affect attractiveness of Nulure droplets but did significantly deter feeding by arriving protein-provided flies (though not protein-denied flies); (3) droppings collected from barn swallows, chickens, and unidentified birds on apple trees were significantly more attractive than solutions or droplets of Nulure to protein-denied flies; (4) droppings that were freshly deposited or fresh from cold storage were significantly less attractive than droppings held under ambient conditions for 1 or 2 days; (5) droppings allowed to dry for 1 day at 25 °C, 60% RH were no less attractive than droppings that received water to simulate dew or rainfall; and (6) droppings treated with antibiotics were significantly less attractive than droppings not treated with antibiotics, indicating that bacteria may be involved in generating attractive volatiles. Together, these findings suggest that in situations where natural sources of protein such as bird droppings or insect honeydew are abundant, apple maggot flies may be relatively unaffected by addition of proteinaceous bait to insecticide sprays.

The life history, behaviour, and mortality of the western ash bark beetle, Hylesinus californicus (Swaine), was investigated in green ash, Fraxinus pennsylvanicus var. subintergerrima (Vahl) Fern., in Calgary, Alberta. This species is univoltine with an apparent obligate diapause in the adult (overwintering) stage. Adults emerge from overwintering sites in the bases of ash boles from mid-April to mid-May and fly or walk up the bole to the crown where maturation feeding, mating, and reproduction occur. Eggs are present by late April, larvae by early May, pupae by mid-July, and new adults by late July. There are three larval instars. Beetles emerge from larval galleries in August and enter fresh phloem in uninfested parts of branches to feed for up to 6 weeks. Beetles leave feeding galleries from mid-September to early November and migrate by walking, falling, and flying to overwintering sites in the base of ash boles. Total mortality from egg to eclosed brood adult was 80.6%. Disease, parasitoids, and dehydration were the main causes of mortality. Eight hymenopterous parasitoid species were identified; the pteromalid wasp Rhaphitelus maculatus Walker was the most abundant. Tree hazard rating, maintenance of tree health, removal of susceptible and infested host material, and application of pesticides are suggested for management of western ash bark beetle populations.

The genus Frontiniella Townsend is transferred from the Eryciini to the Goniini, based on the production of microtype eggs in adult females. Frontiniella is known only from the Nearctic Region and the northern extreme of the Neotropical Region. Eufrontina Brooks is newly synonymized with Frontiniella and all species formerly placed in that genus are transferred to Frontiniella. Frontiniella is hypothesized to be monophyletic based on two derived character states: long hairs on the male surstylus, and elongate posterior spiracles on the puparium. Two species groups are recognized, one with six species and the other with four: the parancilla-group with F. parancilla Townsend, F. incarcerata sp.nov. (type-locality Hwy. 366, Graham Co., Arizona, USA), F. spectabilis (Aldrich) (new combination), F. surstylata sp.nov. (type-locality near Olustee, Florida, USA), F. jorgenseni sp.nov. (type-locality 20 miles northwest of Kenna, New Mexico, USA), and F. ethniae (Brooks) (new combination); and the festinans-group with F. festinans (Aldrich and Webber), F. apache sp.nov. (type-locality Sulphur Draw, Chiricahua Mts., Arizona, USA), F. mitis (Curran), and F. regilla (Reinhard). This revision includes a key to the 10 known species of Frontiniella, a description of each species (including puparium where known), maps of species distributions, an annotated list of hosts (including corrections to previously published records and additions from material examined), and illustrations of taxonomically useful features.

A survey is made of the major features of the venation, articulation, and folding in the hind wings of Coleoptera. The documentation is based upon examination of 108 Coleoptera families and 200 specimens, and shown in 101 published figures. Wing veins and articular sclerites are homologized with elements of the neopteran wing groundplan, resulting in wing vein terminology that differs substantially from that generally used by coleopterists. We tabulate the differences between currently used venational nomenclature and the all-pterygote homologous symbols. The use of the neopteran groundplan, combined with the knowledge of the way in which veins evolved, provides many strong characters linked to the early evolutionary radiation of Coleoptera. The order originated with the development of the apical folding of the hind wings under the elytra executed by the radial and medial loop. The loops, which are very complex venational structures, further diversified in four distinctly different ways which mark the highest (suborder) taxa. The remaining venation and the wing articulation have changed with the loops, which formed additional synapomorphies and autapomorphies at the suborder, superfamily, and sometimes even family and tribe levels. Relationships among the four currently recognized suborders of Coleoptera are reexamined using hind wing characters. The number of wing-related apomorphies are 16 in Coleoptera, seven in Archostemata + Adephaga–Myxophaga, four in Adephaga–Myxophaga, seven in Myxophaga, nine in Archostemata, and five in Polyphaga. The following phylogenetic scheme is suggested: Polyphaga [Archostemata (Adephaga + Myxophaga)]. Venational evidence is given to define two major lineages (the hydrophiloid and the eucinetoid) within the suborder Polyphaga. The unique apical wing folding mechanism of beetles is described. Derived types of wing folding are discussed, based mainly on a survey of recent literature. A sister group relationship between Coleoptera and Strepsiptera is supported by hind wing evidence.

A 4-year field cage study was conducted to determine what effects feeding of alfalfa plant bug, Adelphocoris lineolatus (Goeze), late in the season had on alfalfa seed yields. When zero, one, two, or four alfalfa plant bugs were placed in sleeve cages containing stems of alfalfa at the green pod stage of growth, there was a significant decrease in the number of pods per cage and per raceme, the number of healthy seeds, and the weight of seeds with two or four bugs per cage. Increasing the duration of infestation resulted in significant increases in the number of damaged seeds per cage. An insecticide field trial was conducted in north central Saskatchewan in 1988 to determine what effects the occurrence of plant bugs had on seed yields of alfalfa. Alfalfa plant bug, lygus bug (Lygus spp.), pea aphid [Acyrthosiphon pisum (Harris)], and beneficial arthropod populations were monitored from 23 June to 1 September 1988. Seed yields were significantly greater in plots that were treated with trichlorfon in June and in June and August than in plots that were treated in August alone. The implications of a large alfalfa plant bug population late in the season to alfalfa seed production in the area are discussed.

The nine species; of Timema Scudder known previously from California, Arizona, and Nevada are redescribed and three new species are added: Timema nakipa from Baja California, Mexico: T. tahoe from Nevada; and T. cristinae from Santa Barbara County, California. Timema nakipa and T. podura Strohecker are the only representatives of Timema known from Mexico. Keys and identification tables are presented for identification of species.

Fifteen compounds used for suppression of lepidopteran pests of citrus were applied in a commercial manner to lemon trees. Amounts of dislodgable residues, together with mortality of Aphytis melinus DeBach confined on treated foliage, were monitored for 36 days following treatment. Most materials caused high mortalities on the 1st day following treatment. Several materials had little effect on A. melinus after 7 days post-treatment. These included a formulation of Bacillus thuringiensis Berliner endotoxin, a formulation of B. thuringiensis exotoxin, cryolite, methomyl, mevinphos, naled, parathion, and trichlorfon. Carbosulfan, chlorpyrifos, esfenvalerate, fluvalinate, methomyl, and two formulations of carbaryl caused mortality for up to 30 days post-application. Mortality in the thiodicarb treatment was above 60% for the 36 days of the study. Mortality was correlated with amounts of dislodgable residue for each material tested.

A summary of distribution and biology of the five species of Galapagos Dytiscidae is given, along with a key for identification. Rhantus galapagoensis sp.nov. Balke and Peck is described from San Cristobal Island, Galapagos; important features are illustrated. The source of the dytiscid fauna is tropical America. The limited diversity of the dytiscid fauna is probably caused less by problems of dispersal and more by problems of colonization of islands that experience intense periodic drought.

Resistance of horn fly, Haematobia irritans (L.), to fenvalerate and permethrin was evaluated in Manitoba from 1987 to 1989. The number of resistant populations and the intensity of resistance increased during the period. In 1987, resistant flies were observed on three of 18 herds sampled. Resistance, determined by comparison with a susceptible strain at the LC50, was less than 6-fold for fenvalerate and 3-fold for permethrin except for one population whose resistance was 14-fold for permethrin. In 1988, resistant flies were observed on six of 26 herds sampled. Resistance ranged from 0.03- to 38-fold for fenvalerate and 0.1- to over 100-fold for permethrin. In 1989, resistant flies were found on 10 of 22 herds sampled. Resistance ranged from 1- to 62-fold for fenvalerate and 0.8- to over 100-fold for permethrin. Resistant populations were interspersed among susceptible ones.

We tested the hypothesis that the pattern of development and growth of a generalist parasitoid wasp varies in different hosts. We reared Ephedras californicus Baker (Hymenoptera: Aphidiidae), a solitary parasitoid of aphids, under controlled laboratory conditions on five kinds of hosts: nymphal instar 1 (24 h old), 2 (42 h), 3 (96 h), and 4 (144 h) of apterous virginoparae of Acyrthosiphon pisum (Harris), and nymphal instar 1 (24 h) of Macrosiphum creelii Davis (Homoptera: Aphididae). Parasitoid dry mass increased with the host instar at parasitization. Females were larger than males although the degree of sexual size dimorphism declined with increased host size. Development time from oviposition to adult eclosion varied non-linearly with the host instar at parasitization, and was shortest in first and fourth nymphal instars. Parasitoids developing in M. creelii gained more mass in less time than their counterparts developing in A. pisum of the same initial size. In low-quality hosts, parasitoids apparently trade off increased development time for a gain in adult mass. A possible explanation of sexual size dimorphism in E. californicus is that large females may be able to overcome aphid defensive behaviours better than small ones.

Microplitis mediator (Haliday), a braconid parasitoid reared on the bertha armyworm, Mamestra configurata (Walker), entered diapause at 16 °C and a 12L:12D (100%) or 14L:10D photoperiod (99%) but not at 16 °C or 21 °C under a 16L:8D photoperiod or at 21 °C and a 12L:12D photoperiod. Diapause development was accelerated by cold treatment; adults emerged from diapause more rapidly with increasing duration of cold exposure at least up to 120 days. The main pupation site was found to be on senescent canola leaves which formed a leaf litter on or near the plants. Nearly all unparasitized fourth-instar hosts (98–100%) were found on host plants, whether the conditions induced diapause or not. Only 16–23 and 0% of parasitoids pupated on host plants under conditions of non-diapause or diapause induction, respectively. Because the pupation site of the parasitoid depends on movement of the host, these results suggest that mature parasitoid larvae modify movement of their host.

The alarm pheromone of the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is present in the droplet of anal fluid produced by second-instar nymphs when attacked by predators. Because the anal droplet is used in defense against arthropod predators, it was hypothesized that the alarm pheromone (decyl acetate plus dodecyl acetate) acts as a defensive allomone. This hypothesis was refuted by the demonstration that two predators use the pheromone as a prey-finding kairomone. On a leaf arena, Orius tristicolor White (Hemiptera: Anthocoridae) increased its rate of turning in response to the pheromone, and spent 25% of its time within 5 mm of a pheromone source. When given a choice between connected leaf discs containing a pheromone- or solvent-treated wick, Amblyseius cucumeris (Oudemans) (Acarina: Phytoseiidae) spent a greater proportion of time on the pheromone-containing disc, suggesting an arrestment effect.