A typical lake outlet of the Canadian Shield was treated for 15 min with a high dose (5.28 g/L s−1 of discharge) of Teknar®, a commercial formulation of Bacillus thuringiensis serovar. israelensis. Efficacy on Simuliidae larvae and impact on non-target aquatic insects of this stream were monitored using drift nets, counting plates, and artificial turf substrates along a 1000-m section downstream of the site of application. Compared with a 4-day pre-treatment average for 12-h sampling periods, drift of Simuliidae increased from 64 to 92 ×, with shorter peaks of 133–184 ×, 2–6 h after treatment. There was no evident drift increase in larvae of Ephemeroptera, Plecoptera, Trichoptera, Chironomidae, or dipterous pupae, but larvae of Blephariceridae (Diptera) were severely affected as their drift was increased by up to 50 × and remained high for 3 days. After 30 h the mortality of Simuliidae on counting plates ranged from 95 to 82% in the first 300 m, with detachment rates of 78.5–46.5%. Densities of non-target insect larvae were not reduced on the artificial substrates, except for 2 genera of Chironomidae (Eukiefferella and Polypedilum) which were reduced 26 to 39% of their original density. Drifting larvae of 1 chironomid genus (Phaenopsectra) also showed symptoms of toxemia by B.t.i. The main impact of the treatment was thus seen in 2 Nematocera families (Chironomidae and Blephariceridae) which were mainly exposed to B.t.i. sedimented on the bottom of the stream or attached to periphyton growing on rocks.

Under axenic conditions, larvae of Delia antiqua develop to the adult stage on onion agar only if the agar is supplemented with mixtures of 10 essential amino acids and 8 water-soluble vitamins. The omission of the amino-acid mixture allowed no development past the first instar. When the vitamin mixture was omitted, 1 of 25 larvae developed to the pupal stage. Omission of individual vitamin supplements caused less marked effects. Omitting supplemental choline, thiamine, pyridoxine, or pantothenic acid had no significant effect on development. Omitting supplemental biotin or nicotinic acid resulted in suboptimal development to the adult stage. Omitting riboflavin or folic acid resulted in development to the adult stage, but the adults did not lay viable eggs. Presumably nutrients that are in insufficient supply in onion tissue are supplied by bacteria in nature.

The egg and larval instars of Pachybrachis peccans Suffrian and P. bivittatus Say are described and illustrated. Adults of both species appear in late May, feed on willow leaves, mate and oviposit in June–July. The larvae, unable to climb the host plants, feed in the leaf litter of dead leaves of willow; they reach the second-last or last instar by the end of the fall; then they seal their case and overwinter. Pupation occurs the following spring, probably in early May.

Larval instars can be distinguished as follows: first instar with egg bursters on meso- and metathorax, with typical head chaetotaxy consisting of flattened-papillate setae and 1 pair of very long simple setae, and tibiae with 2 pairs of spiniform setae; older instars without egg bursters, and showing differences in size, in head and pronotal chaetotaxy, and in the number of spiniform setae on the tibiae.

In the larvae, the premental sclerites of the head seem to be present throughout the Campsomata, a group with case-bearing larvae and not only in the Lamprosomatinae as previously reported.

The biology of Telenomus chloropus Thomson was studied on eggs of Nezara viridula (L.) which had been reared on the stink bug resistant soybean, Glycine max (L.) Merrill, genotype PI 171444 and the susceptible cultivar Davis. Time of development of T. chtoropus from egg to adult emergence was not significantly different in eggs oviposited by N. viridula reared on either Davis or PI 171444. However, successful emergence of T. chloropus from host eggs was significantly lower for parasitoids that developed in eggs from N. viridula reared on PI 171444. Longevity of adult T. chloropus was not significantly different between females that were allowed or denied oviposition regardless of the genotype fed the host. Total fecundity of T. chloropus reared from eggs of N. viridula fed PI 171444 was one-half that of parasitoids from the Davis treatment. Although ovipositional patterns over the lifetime of parasitoids from the 2 treatments were similar, the mean number of progeny produced per day was significantly greater in the Davis treatment. Also, the ovipositional period of parasitoids from the PI 171444 treatment was shorter than for parasitoids from the Davis treatment.

The responses of 11 population samples of sixth-instar larvae of the western spruce budworm, Choristoneura occidentalis Freeman, to carbaryl spray were determined. Representatives of one population each from Arizona, Idaho, Montana, New Mexico, and Washington were included. Five response levels of progressively higher tolerance were apparent; the most tolerant population sample was ca. 18 times more tolerant than the most susceptible sample to carbaryl. Trends in relationships of site characteristics and response to carbaryl were not evident. Previous spray history of an area, however, appeared to be related to response at a site; populations from sites sprayed with DDT were significantly more tolerant than those from sites where DDT had not been used. The most tolerant groups were collected from a Montana population in an area where both DDT and carbaryl had been applied. The electrophoretic characteristics of each population sample were determined. No loci detectable by electrophoresis were correlated with response to carbaryl.

To assess whether canola seed is more susceptible to infestation than rapeseed, the food preferences, survival, and development of 4 major insect pests of stored products were tested in the laboratory on seeds of 10 cultivars of rapeseed and canola. Adults of the merchant grain beetle, Oryzaephilus mercator (Fauvel), the sawtoothed grain beetle, O. surinamensis (L.), and the red flour beetle, Tribolium castaneum (Herbst) preferred cereal diets on which they are normally reared to any of the rape or canola cultivars. The rusty grain beetle, Cryptolestes ferrugineus (Stephens), preferred wheat kernels of 15% moisture content to these cultivars. Insects did not prefer any one of the rape and canola cultivars, and attempted to avoid them. Survival of the 4 species was higher and developmental time shorter on control diets than on the rape and canola cultivars. Oryzaephilus mercator produced only a few progeny on cv. Zephyr, and T. castaneum on cvs. Midas and Tower. No correlations were found between survival or development time and glucosinolate or erucic-acid content. Much higher survival of O. mercator occurred when tests were started with newly emerged larvae than with eggs. Survival was substantially lower on ground than on whole seeds. No evidence was found to indicate that canola seed is more susceptible to infestation than rapeseed.

The alfalfa leafcutter bee, Megachile rotundata (F.), is the primary pollinator of commercially grown seed alfalfa in Canada. Chalkbrood is a fungal disease, caused by a complex of Ascosphaerales species (Skou and King 1984) that infect the larvae of many species of bees. One species, Ascosphaera aggregata Skou (Skou 1975), is a severe problem in leafcutter bees in the United States and in some cases has caused losses of more than 65% (Stephen et al. 1981). Mode of dispersal, infestation of bee larvae, sporulation, and associated symptomatology of this pathogen have been described (Vandenberg et al. 1980; Vandenberg and Stephen 1982; McManus and Youssef 1984).

From 1981 to 1984, a low-spray management program was employed against injurious arthropods on the 40 disease-resistant apple trees in my experimental orchard in Massachusetts. The program consisted of an annual early-season application of petroleum oil followed by 2 applications of phosmet (1 at petal fall and another 10–14 days later). Visual traps were used to suppress Rhagoletis pomonella flies. For all years combined, a mean of 89.7% of fruit sampled at harvest in this orchard was free of insect injury compared with 0% uninjured fruit on neighboring unsprayed trees. Populations of foliar-feeding pests never reached injurious levels.

Mean weekly catch of adult Psila rosae (F.) on sticky, yellow-painted cardboard traps from 93 commercial carrot fields provided seasonal records of their activity during 1980–1983 in the lower Fraser Valley, British Columbia. When monitoring extended from April through November in 1982 and 1983, 3 distinct periods of adult activity were observed that probably reflect the occurrence of 3 adult generations per year. Trap catch first peaked in mid- to late-May, followed by a second peak in late-July to early-August, and a third peak in mid-October. Of the temperature summations calculated, those commencing 1 February provided the most accurate degree-day (DD) indices for predicting seasonal activity of overwintering and 1st-generation adults. Four-year means for cumulative DD above 3 °C (air temperature) after 1 February for first, 10%, maximum, and 90% trap catch of the overwintering generation were 326, 435, 557, and 838 DD, respectively.

Xylosandrus germanus (Blandford) (Coleoptera: Scolytidae) is an ambrosia beetle that occurs in Japan, Korea, the Kuril Islands, Vietnam, Taiwan, China, Central Europe, and the United States (Nobuchi 1981). Unlike most ambrosia beetles, it will attack apparently healthy trees and those that are dying or recently dead (Weber 1982). It has been associated with plants infected with pathogenic fungi, including black walnut (Juglans nigra L.) infected with species of Fusarium (Anderson and Hoffard 1978; Kessler 1974); reported symptoms include cankers, wilting and dieback, and sprouts. We found black walnut with wilting and dieback symptoms in southern Illinois in spring 1978 and central Tennessee in spring 1980. Subsequent examinations showed that X. germanus was present and apparently closely associated with the disease symptoms because of the number of diseased trees that also contained X. germanus pinholes. Therefore, we decided to study the relation between X. germanus attack and disease symptoms in black walnut.

The species previously recognized as Euxoa ridingsiana (Grt.) is shown to be composed of a sympatric pair of sibling species, Euxoa ridingsiana (Grt.) and Euxoa maimes (Sm.), which in the laboratory will produce viable F1 hybrids but no F2. Results of F1 sib and backcrosses show that the F1 males are fertile and the F1 females are infertile. In mating-bias tests conducted in laboratory cages, 74% of matings were conspecific and 26% interspecific. Differences in the diel periodicities of mating, which are about 2 h out of phase, may account for the mating bias. The duration of development of E. ridingsiana in the laboratory and its seasonal flight period in the field are about 2 weeks in advance of that of E. maimes. However, there is considerable overlap of the flight periods and, with the tendency of females of both species to mate several times, it is unlikely that the difference in seasonal emergence is enough to effect reproductive isolation. It is evident that, under natural conditions, reproductive isolation can be maintained entirely by species-specific sex pheromones. This mechanism of reproductive isolation is, however, apparently ineffective when moths are confined in cages in the laboratory.

Biogeographic considerations suggest that the differences in life-cycle timing and mating periodicities might have been adaptations to adjust development and reproduction to prevailing ancestral environments. If the initial differentiation of the 2 species occurred in isolation and included at least an incipient shift in the pheromonal mate-recognition system, it is possible that upon reestablishment of contact between ancestral populations the differences in life-cycle timing and mating periodicities acting in concert could have effected substantial, albeit incomplete, reproductive isolation. Subsequent selection to reinforce assortative mating to preserve coadapted gene complexes could then have resulted in differentiation of discrete pheromonal systems and attainment of species status.

Three pyrethroids, deltamethrin, fenvalerate, and cyfluthrin, were assayed against 2nd-instar nymphs of the grasshopper Melanoplus sanguinipes (Fab.) at 5 dosages and at 5 post-treatment temperatures ranging from 15.6 to 37.8°C. All three showed a negative temperature coefficient of toxicity but there was considerable variation in the pattern of response. Deltamethrin proved to be the most effective and cyfluthrin the least effective, both in terms of the amount of active ingredient required for 90% mortality and in having the lowest negative coefficient, respectively. The extent of the negative temperature coefficient of toxicity was much more pronounced at the LD90 than the LD50. Apparent mortality was recorded at 24, 48, and 72 h post-treatment and with each of the pyrethroids, recovery of some hoppers took place after 24 h. This phenomenon of delayed recovery was greatest at the lower temperatures.

In the subfamily Tanypodinae (Diptera: Chironomidae), 11 pairs of setae and 3 pairs of sensory pores are found on the larval head capsules. The structure and position of these cephalic setae and sensory pores exhibit strong generic differences but vary little between species within a genus. A generic key to the Tanypodinae utilizing these differences is presented for larvae of the following genera: Clinotanypus, Coelotanypus, Natarsia, Tanypus, Djalmabatista, Procladius, Psectrotanypus, Brundiniella, Macropelopia, Ablabesmyia, Guttipelopia, Hudsonimyia, Krenopelopia, Labrundinia, Larsia, Monopelopia, Nilotanypus, Paramerina, Pentaneura, Telopelopia, Thienemannimyia, Trissopelopia, and Zavrelimyia. The delineation of the frontoclypeal apotome can be used to distinguish fourth-instar from third- and earlier-instar larvae.

To test the hypothesis that bark beetles and some associated insect species are attracted to ponderosa pines infected by Ceratocystis wageneri, insect visitations on 11 severely diseased, 9 moderately diseased, and 10 apparently healthy trees were monitored from 1 August to 15 October 1972. Larger numbers of Dendroctonus brevicomis, D. ponderosae, Temnochila chlorodia, and buprestids were captured on diseased trees uninfested by bark beetles than on apparently healthy ones, thus possibly indicating attraction to diseased trees. There was strong evidence that D. valens and Spondylis upiformis were attracted more frequently to wounds on diseased than on healthy trees. Arrival patterns of beetles were recorded for trees that became infested during the study. Predators became abundant on traps as bark beetle catches increased.

A new subspecies, Ornithoptera (Schoenbergia) tithonus misoolana from Mysol Island, Indonesia is described, from the ♀, only.

When I was asked to serve as moderator for a symposium on the “Economics of Entomological Effort”, I was honored and pleased to accept. The honor became abundantly clear when I received the full details of the symposium and recognized the high caliber of the speakers who would participate. The pleasure to accept derived from the great importance of the subject and my own conviction that neither the public, the scientific community, nor the administrators of research realize fully the economic importance of studies on insects. It is therefore timely that this symposium be held, a symposium that has as its purpose to show how efforts in entomology contribute to public welfare through advances in the discipline and through “spin off” to other areas of science.

The efficacy of Bacillus thuringiensis was evaluated against the large aspen tortrix on trembling aspen in Alaska. A concentration of 4 × 109 IU per 378.5 L of water was applied to infested trees using a hydraulic sprayer. Treatments with Dipel 4L and Thuricide 32LV resulted in population reductions of 69 and 76% respectively. Both products provided significant foliage protection. Timing of treatment is critical to successful population suppression and foliage protection.

Shivaphis catalpinari sp. nov. from Celtis australis L. is described. The taxonomic position of this aphid with respect to the other species of the genus is discussed.

Elymana sulphurella (Zetterstedt) is confirmed as an introduced European species, and is distinguished from its relatives in the New World, including 2 new species E. circius (British Columbia to Saskatchewan) and E. pacifica Hamilton (British Columbia). Elymana acrita DeLong 1936 is synonymized with E. acuma DeLong 1936, and E. caduca DeLong 1936 is synonymized with E. inornata (Van Duzee 1892). A key to the New World species is presented. A method of rearing E. sulphurella in a controlled environment is described. Of 11 plant species tested as food hosts, Agrostis gigantea Roth., Elymus glaucus Buckl., Festuca arundinacea Schreb., F. elatior L., F. rubra L., and Phleum pratense L. were suitable for nymphs and adults, Lolium perenne L. for nymphs, and Alopecurus pratensis L., Bromus inermis Leyss., and Dactylis glomerata L. for adults. Digitaria sanguinalis (L.) Scop. and Echinochloa crus-galli (L.) Beauv. were unsuitable for both stages. Ten of 11 plant species tested as oviposition hosts yielded nymphs but the numbers varied widely. Leaf blades were preferred over sheaths as oviposition sites and most eggs were laid in the lower two-thirds of the leaf. Eggs appeared to be in diapause when laid and required several months to hatch if held at room temperature. Cold treatment of such eggs decreased the minimum hatching time and reduced the period over which hatching occurred. The mean developmental period of females was 24.9 days and males 23.5 days. The mean longevity of mated females (83.2 days) was significantly (P = 0.05) longer than that of males (62.1 days).

Spelobia tenebrarum is a troglobitic sphaerocerid restricted to a large number of isolated eastern North American caves. The Quaternary origin of this species from its sister species, S. semioculata, is discussed.