The production of excess males in thelytokous Muscidifurax uniraptor Kogan & Legner was triggered by high temperature (32.2 °C) during oviposition, and may result from a blockage of endomitosis in the egg. A minimum oviposition period of 24 h at 25 °C prior to continuous high temperature was an important prerequisite. A few receptive oocytes may be present before oviposition, with new ones formed during the first 24 h of the oviposition period at 25 °C. Although heat treatment must begin during a relatively short receptive period ("window of susceptibility") early in adult life, it has to persist longer than 24 h at low oviposition rates (20 hosts/day) and < 24 h at high oviposition rates (50 hosts/day) to block effectively endomitosis and the formation of diploid, female-producing eggs.

Vol. 117, 1985. pp. 737-762.

p. 745, 1. 7: “Ceraeochrysae placita” should read “Ceraeochrysa placita”.

The sex-pheromone components of the sibling species Euxoa ridingsiana and Euxoa maimes were identified in abdomen-tip washes and extracts of calling female moths. Both species produced the same primary pheromone component, (Z)-9-tetradecenyl acetate (i.e. Z9-14:Ac), but they produced different amounts of secondary pheromone components. In the field, male moths of E. ridingsiana were specifically attracted to a 3-component blend of Z7-12:Ac, and Z7-14:Ac, and Z9-14:Ac in a ratio of 1:2:40 at 500 μg per dispenser, and males of E. maimes were specifically attracted to a 5-component blend of Z7-14:Ac, Z9-14:Ac, Zl 1-14:Ac, Zll-16:Ac, andZll-16:OH in a ratio of 1.5:500:5:50:2.5 at 500 μg per dispenser. Both synthetic pheromone blends were competitive with conspecific females. These pheromone analyses confirm that E. ridingsiana and E. maimes are valid biological species that can maintain their reproductive isolation solely by specific sex pheromones.

The thyantae group of Trissolcus is characterized by the presence of abundant long setae on the metapleuron. All known New World species occur in the Nearctic, viz. T. thyantae Ashmead (eastern USA and Canada), T. occiduus n. sp. (western USA), T. parma n. sp. (widespread), and T. ruidus n. sp. (Arizona, New Mexico). An identification key is provided and all species are described or redescribed. Data on distributions and hosts (Heteroptera: Pentatomidae) are summarized.

Organizers of this year's conference chose a surprising theme — the economics of entomological effort. It is surprising because, to many professional entomologists, economics is a foreign and little-understood subject area that has limited applicability to their work. There have been few examples of entomological effort that involved the working together of professionals from both disciplines.

Demographic analysis of a species population can be useful in gaining insight into its dynamics in a particular environment. The calculated intrinsic rate of increase of a population may be valuable in predicting population performance. As a single, discrete value, it serves as a quantitative measure, or ecological index, of the response of a species to a set of environmental conditions (Birch 1948; Messenger 1964).

Seedworms of the Cydia piperana complex are major cone pests of ponderosa pine, Pinus ponderosa Douglas ex-Lawson, and Jeffrey pine, P. jeffreyi Greville and Balfour, in western North America (Keen 1958; Hedlin 1967). An effective synthetic attractant could be useful in a trapping technique for predicting damage to seed crops.

Male moths of a biotype in this complex were lured to traps baited with (E)-9- and (Z)-9-dodecenyl acetates during tests to.refine optimum blends of these synthetic chemicals for Rhyacionia and Eucosma shoot moths, and we report the serendipitous findings here.

“Fundamental” or “basic” entomological research may be defined as any research that has insects as the organisms under study and that does not have as its immediate objective the eradication or reduction in numbers of these insects. Within the framework of this deliberately broad definition may be included:

(1) Most, but not all, research done by entomologists in universities, closeted away in their “ivory towers” and generally appearing to the public not to care much about what goes on in the rest of the world. The motivation behind this research is the intrinsic curiosity of the scientist towards insects.

Functional wing length (wing length/head-capsule width) of female Sweltsa revelstoka (Jewett) from streams was measured for 19 sites that have been free of Wisconsin glacial ice for about 15 000 years and possibly longer, and from 23 sites that have been ice free for about 10 000 years. At the former sites brachypterous populations were common and there was a significant negative relationship between functional wing length and elevation, and a positive relationship between functional wing length and stream size. In the area that deglaciated more recently, populations were not or only slightly brachypterous and there was no significant relationship between wing length and elevation or between wing length and stream size. Functional wing length was not related to body size. These analyses indicate that the brachypterous condition is probably genotypic in origin. I suggest that streams were colonized by macropterous forms shortly after deglaciation, and that brachyptery takes several millennia to develop at small, high-elevation streams.

The beet leafhopper, Circulifer tenellus (Baker), was found to be significantly attracted to the color yellow. Yellow, opaque plastic cards coated with a sticky substance were shown to be an effective survey tool for monitoring adult beet leafhopper. Traps with different hues of yellow (wavelengths of 510 and 588 nm) showed no significant differences between trap catches. The commonest flight strata at a host site was at ground level, where significantly higher numbers of adults were trapped than at heights of 0.3, 0.6, 0.9, 1.5, 2.1, and 2.7 m above the ground. The ground level is the optimum location for a yellow sticky trap when monitoring C. tenellus.

Losses in yield of spring wheat due to infestations of Sitodiplosis mosellana (Géhin) were determined for 700 000 ha of arable land in northeast Saskatchewan, Canada in 1983. The proportion of kernels infested (y) was a power function of the number of wheat-midge larvae (x) (y = 35.3x0.725). One, 2, 3, and 4 larvae per kernel resulted in a level of infestation of 38, 58, 78, and 96%, respectively. There was no significant difference between infestation levels from fields sampled at the heading stage of crop growth and the estimates of infestation levels for these fields at harvest time. Yield of grain (y) was negatively exponential to an increase in level of infestation (x) (ln y = 5.7−0.017x). Infestations of 30, 60, and 90% reduced yields of spring wheat by 40, 65, and 79%, respectively. The average decrease in crop yield in the study area was about 30%, which resulted in estimated losses in total gross revenue of about $30 million.

Carrot rust fly (CRF), Psila rosae (Fabricius) (Diptera: Psilidae), caged with 2-month-old carrot plants at 20 °C, 50–70% RH, and 16:8 L:D laid an average of 109 eggs per female. With ca. 50% survival from egg to pupae, the rearing procedure yielded a 25 × population increase per generation. The duration of the life cycle at 20 °C was ca. 65 days. Calculated threshold temperatures and degree days above those temperatures necessary for complete development were: eggs, 4.5 °C and 94 degree days (°D); larvae, 2.02 °C and 625 °D; and pupae, 1.47 °C and 374 °D. Larvae collected in the field in fall developed normally when incubated at 22 and 19 °C; ca. 40% of the pupae entered diapause at 16 °C, and 100% at 13 and 10 °C. Fall-collected larvae chilled at 1 °C for ca. 3 months developed normally at all temperatures including those which induced diapause in pupae from unchilled larvae. With laboratory-reared pupae, 100% diapause was induced with > 10 days exposure to 13 or 10 °C. Twenty weeks storage at 1 °C was sufficient to terminate diapause in > 95% of the pupae. The ability of both CRF larvae and pupae to survive cold temperature conditions suggests that 2 separate spring emergence peaks may occur, which could have important implications if the spring flight is to be predicted on the basis of °D accumulations.

The effect of trap color on sticky-trap catches of Pholetesor ornigis Weed was studied in experimental and commercial apple orchards during each of the parasite's 3 yearly activity periods during 1982–1984. Seven enamel and 5 fluorescent paints were compared in 8 trials. There was considerable between-trial variation in the percentage of the total number of P. ornigis caught on a trap of one color. Trap color had a significant effect on the total number of parasites caught. There were no consistent differences in the relative attractiveness of the different colors to males and females. During 1984, males comprised more than 75% of all parasites trapped during each of the 3 activity periods. The sex ratio of the adult population emerging in study orchards during 2 of these activity periods was approximately 1:1.

The disruption of chemical communication between adult insects by the use of synthetic sex pheromones is an attractive method of insect control. However the mechanism of disruption is not clearly understood. It is generally considered that 3 mechanisms are in operation (see review by Bartell 1982): masking of the natural-pheromone plumes by permeation of the atmosphere with synthetic pheromone; orientation of males to false trails; and habituation of the central nervous system by prolonged or repeated exposure to the pheromone. The relative importance of these 3 mechanisms in disruption is of concern, as this can affect the strategy for disseminating the pheromone.

In 1982 and 1983, silhouette traps, sticky traps, and suction traps with and without dry-ice bait were evaluated for sampling populations of black flies that are pests of cattle in central Alberta. The dry-ice-baited silhouette trap was the most effective. The black-fly species collected were Simulium arcticum, S. aureum, S. decorum, S. meridionale, S. tuberosum, S. venustum, S. verecundum, S. vernum, and S. vittatum. Approximately 80% of the black flies collected each year were S. arcticum, the primary pest species of cattle in Alberta.

Direct-contact toxicity tests were done with 21 insecticides to assess their potential for controlling adults of the carrot rust fly, Psila rosae (Fabricius) (Diptera: Psilidae). Chlorpyrifos, chlorfenvinphos, fensulfothion, carbofuran, cypermethrin, and mevinphos were 1.2 to 2.8 ×, and deltamethrin 22 ×, more toxic to flies (24–48 h old) than was diazinon, the insecticide currently used most commonly to suppress first-generation adults of the carrot rust fly.

Vol. 116, 1984. pp. 1591-1603.

A biosystematic revision of the genus Stenonema (Bedmarik, A.F., and W.P. McCafferty.

The economic importance of research in veterinary–medical entomology is inadequately defined. In this paper we attempt to assess progress in bioeconomics and feasible approaches to estimate benefits from this field of study.

Benefits accruing from veterinary–medical entomology are in improved efficiency or increased productivity of man and his animals. Assessing this effort has been neglected because of difficulty and expense in measuring loss. Even if direct losses were known, indirect ones due to insect-borne diseases and other health-related factors are generally immeasurable.

A hood incorporating a removable air filter and an electrostatic dust precipitator reduced the numbers of air-borne scales around laboratory workers handling insects, thereby reducing the occupational hazard of allergic reactions. The hood is mobile and easy to maintain. Construction details are provided.

Secondary metabolites from plants capable of photosensitizing insects include furanocoumarins, furanoquinone alkaloids, beta-carboline alkaloids, polyacetylenes and their thiophene derivatives, and extended quinones (Arnason et al. 1983; Towers 1984). These compounds may have direct lethal effects, retard larval development, or be ovicidal (Kagan and Chan 1983). A remarkable property of these secondary metabolites is their greatly enhanced activity in the presence of sunlight or artificial sources of radiation.