The chalcidoid wasp, Hemadas nubilipennis (Ashmead), induces a reniform gall on the adventitious shoots of lowbush blueberry. Eggs are laid within shoot tissues 5–15 mm below the tip and then the female destroys the apex of the shoot by stabbing with her ovipositor. Stabbing terminates growth of the shoot, and as a result all nutrients flowing into the shoot are redirected towards the gall tissues and larvae. This is a rare example of an insect damaging tissues of the host plant for the benefit of the offspring. It also is suggested that stabbing and gall formation have a pruning effect on the host plant.

Numerous studies have shown that the cuticle of insects is complex and highly-differentiated and that the complexity varies from species to species (2, 8, 11, 13, 14, 17, 18).

The object of this study is to determine cuticular relationships between the grasshopper, Melanoplus bivittatus, and other insects already studied. This work was carried out by means of chemical tests and permeability measurements on fresh material rather than by methods of fixing and sectioning.

Phyllotreta cruciferae (Goeze), an abundant pest in the parklands, is moderately abundant on the open prairie, less common in the southern parts of the boreal forest, and absent elsewhere in the forest. Phyllotreta albionica LeC. occurs in low numbers in parkland and prairie, and is rare in the forest. Phyllotreta robusta (LeC) occurs in low numbers in the parkland, is rare on the prairie, and was not found in the forest. Psylliodes punctulata Melsh., which has a moderately low population in the parkland, occurs in similar numbers on the prairie and perhaps also in the forest. P. cruciferae will likely cause problems in any cruciferous crops grown on the open prairie and eventually in cruciferous crops in newly-cleared forest areas.

Introgression of cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham) (Coleoptera: Curculionidae), resistance from Sinapis alba L. to susceptible Brassica napus L. (Brassicaceae) has produced genetic lines resistant to the weevil in replicated field trials. In the current study, weevil feeding and oviposition on S. alba and on resistant novel lines developed by crossing S. alba × B. napus were less frequent than on susceptible germplasm. Development times were greater and biomass was less when larvae were reared on resistant lines or S. alba. Oocyte development was faster in post-diapause springtime adult female weevils caged on susceptible plants than in those on a resistant line, S. alba, or an early-season food host, Thlaspi arvense L (Brassicaceae). Our results suggest that antixenosis resistance and antibiosis resistance are expressed by resistant lines. These results and previous chemical analyses of these lines also suggest that resistance is potentially influenced by attractive and (or) feeding-stimulant effects of 2-phenylethyl glucosinolate and antifeedant or toxic effects of 1-methoxy-3-indolylmethyl glucosinolate.

Dermestid larvae, Trogoderma versicolor (Creutzer), and adult American cockroaches, Periplaneta americana (Linné), were affected by ruby laser pulses of two intensities, 0.06 ± 0.04 per 10−7 second duration and 0.57 ± 0.06 joules per 0.2 milliseconds. Laser impact areas were 1.5 mm. in diameter. The first intensity, directed at cephalic regions of dermestid larvae, caused mortality in 3–48 hours. The same intensity directed at larval mid-abdominal areas caused visible outer integument and body-hair scorching, cessation of feeding, growth rate, and movement, and loss of negative phototactic responses. Directed at posterior abdominal regions of larvae, it caused damage to the epidermal layer noticeable in four succeeding moults. It caused temporary (10-15 min.) immobility and loss of negative phototaxis when directed at pro-thoracic regions of cockroach adults. P. americana adults were more severely affected by the second laser treatment, exhibiting immobility, loss of negative phototaxis, and cessation of eating. Total mortality in the five treated specimens occurred in 8-14 days as compared with 45-68 days in controls.

Effects of neem formulations on the reproduction and survival of the egg parasitoid Trichogramma minutum Riley were examined to assess the compatibility of the two control strategies in integrated pest management programs. A laboratory bioassay was developed for this purpose, which could be used as a model ecotoxicological system. Eggs of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), which had been treated with an acetone solution containing an azadirachtin-based formulation, were presented to individual T. minutum females. These eggs were held until parasitoids completed development and emerged from the eggs. Survival of T. minutum females 1 day after treatment, number of Mediterranean flour moth eggs parasitized, proportion of parasitized eggs from which adults emerged, and sex ratios of emerging adult parasitoids were determined. Two formulations of neem-seed extracts containing azadirachtin and a purified azadirachtin standard were tested at an operational dose and at 10 times the operational dose. At 50 g azadirachtin/ha (operational dose), no significant effects were observed on survival of parasitoid females. At 500 g azadirachtin/ha, female survival after 1 day was significantly reduced by Azatin EC and Neem EC. No reduction was evident with the 100% azadirachtin treatment, suggesting that other components of the formulations were in part responsible for the toxicity to females. Likewise, at 500 g azadirachtin/ha, the number of eggs parasitized was greatly reduced by Azatin EC and slightly reduced by Neem EC but was not reduced by an azadirachtin standard. These reductions in egg parasitism were probably due to the observed effects on female survival. At 500 g azadirachtin/ha, parasitoid developmental success was reduced by all treatments including the azadirachtin standard. Neem EC and Azatin EC at the lower dose also had a small but significant effect on developmental success. Sex ratio of emerging adults was not affected. These results indicate that azadirachtin is compatible with T. minutum during egg parasitism at operational dosages.

Blackheaded fireworm (Rhopobota naevana (Hbn.)) mating can be disrupted by pheromone components released from spiral polyvinyl chloride (PVC) dispensers in large field plots on cranberry (Vaccinium macrocarpon (Aiton) (Ericaceae)) farms. The main pheromone component ((Z)-11-tetradecen-1-ol acetate (Z11-14:Ac)) or a blend similar to natural pheromone (Z11-14:Ac, (Z)-11-tetradecen-1-ol (Z11-14:OH), and (Z)-9-dodecen-1-ol acetate (Z9-12:Ac)) was released from PVC dispensers into 0.8-ha plots on cranberry farms. Regardless of the treatment, free-flying males in treatment plots located fewer than 5% of individually caged virgin females, whereas mate location in most control plots ranged from 14%–75%. Location of pheromone lures loaded with 1.0 mg of the three-component blend was reduced in both treatments, but not to the same extent as was location of females. The magnitude of mating disruption indicated by 0.01-mg lures was similar to that indicated by caged females. Estimated release rates from dispensers loaded with Z11-14:Ac alone were linear and similar in both years of the study, declining from 575–720 mg/ha per day to 175–220 mg/ha per day after 100 days. Three-component dispensers placed in the field in July 1994 showed a steeper decline in release rates of Z11-14:Ac and a change in component ratios from 6.2:2.5:1 to 8:2:1 (Z11-14:Ac: Z11-14:OH: Z9-12:Ac) over the 60-day release period. After one season of mating disruption, the number of eggs and the number of foliar samples with larval feeding shelters were not consistently reduced in treatment plots. Mated females may have dispersed into the plots and oviposited. PVC dispensers effectively disseminate pheromone for mating disruption but are labor-intensive to use. In the cranberry system, their use might be limited to research plots and isolated farms of <8 ha.

Oil-based formulations of Bacillus thuringiensis Berliner var. kurstaki, Dipel 132, Dipel 176, and Dipel 264, were aerially applied at rates of 1.18–2.36 L/ha over five 30-ha plots in a balsam fir, Abies balsamea (L.) Mill., forest in efficacy tests against the eastern hemlock looper, Lambdina fiscellaria fiscellaria (Guen.), in Newfoundland. Double applications of 30 Billion International Units (BIU) per hectare of each formulation and single applications of 40 BIU per hectare of Dipel 176 and Dipel 264 were tested. Larval population reductions of more than 95% and no defoliation of old or new foliage were observed in the plots receiving double applications and in the plot treated with a single application of Dipel 264. Larval numbers were reduced by 85% and defoliation was 4% in the plot treated once with Dipel 176.

These treatments were applied against low to moderate larval populations, and their success was attributed to excellent spray coverage and early application when 50% or more of the larvae were still in their first instar.

The seasonal occurrence of four species of egg parasitoids of the tarnished plant bug (Lygus lineolaris) was determined in three different habitais: fields of mixed weeds. alfalfa (Medicago sativa L.). and crown vetch (Coronilla varia L.) in southwestern Quebec in 1991 and 1992. Parasitoids studied were the mymarids Anaphes iole Girault, Polynema pratensiphagum (Walley), and Erythmelus miridiphagus Dozier and a scelionid, Telenomus sp. Adult populations of these parasitoids showed three or four population peaks in all habitats throughout the season. Adult parasitoid activity started during the first egg-laying period of L. lineolaris at a temperature accumulation of 73 degree-days (DD). The overwintering period began in mid-October at 1277 and 1058 DD for 1991 and 1992, respectively. All the parasitoids had a strong synchrony with L. lineolaris populations; specifically, marked peaks in the adult population of all species were in synchrony with the egg-laying periods of L. lineolaris.

Three species of egg–larval parasites in the genus Chelonus (Hymenoptera: Braconidae) exhibited host-searching behavior when exposed to body scales from 6 species of Lepidoptera representing 3 families. The nonspecific response to scales from several hosts appears to be of adaptive value to Chelonus spp., as it is consistent with the polyphagous habits reported for this genus. The searching response was more widespread and intense in an Ethiopian Chelonus sp. than in 2 other species. It is thought that the broad responsiveness to host scales may detrimentally affect parasite searching ability through excessive loss of searching time, although sensory adaptation to the kairomones might serve to attenuate such effect. Some coevolutionary aspects of this host–parasite chemical interaction are discussed.

The Nearctic species, as well as several Palearctic species, of Athous Eschscholtz, Harminius Fairmaire, Hemicrepidius Germar, and Acanthathous Champion are studied and rearranged with the following new combinations: the Nearctic Hemicrepidius simplex (LeConte), H. falli (Reitter), and H. palpalis (Fall) (each from Athous); the Palearctic Hemicrepidius hirtus (Herbst) and H. niger (Linnaeus) (each from Athous); Hemicrepidius dauricus (Mannerheim) and H. flavipennis (Cherepanov) (each from Harminius); Hemicrepidius inornatus (Lewis) (from Yukara); and Acanthathous photinoides (Champion), A. campanulatus (Champion), A. mexicanus (Candèze), A. aequinoctialis (Champion), A. marcidus (Champion), A. aztecus (Champion), A. rugipennis (Champion), A. angusticollis (Champion), A. carinicollis (Champion), and A. championi (Schwarz) (each from Athous). Hemicrepidius hirtus (Candèze) (nee hirtus Herbst) is renamed californicus, new name, and the name H. hemipodus (Say) is recognized rather than decoloratus (Say). Pertinent generic characters are illustrated and brief notes are given for each of the above species (except those in Acanthathous) and for Harminius (Diacanthous) triundulatus (Mannerheim), H. (D.) undulatus (DeGeer), and Hemicrepidius pallidipennis (Mannerheim). Renter’s two subgenera of Harminius: Diacanthous and Megathous are recognized. A key to the genera associated with Athous and to the subgenera of Harminius is provided.

In a laboratory study, larvae of the western cherry fruit fly, Rhagoletis indifferens Curran, were successfully reared on an artificial diet consisting of wood pulp, agar, wheat germ, Brewer’s yeast, sugar, salt, choline chloride, ascorbic, citric and propionic acids, cholesterol, methyl para-hydroxybenzoate (MPH), and water. Ten other diets consisting of various ingredients obtained variable results. A premixed tropical fruit fly diet (prepared by Nutritional Biochemicals, Cleveland, Ohio) was not suitable for rearing the cherry maggots. Formaldehyde was not satisfactory as a mold inhibitor.

The eggs were obtained on artificial cherries made up of a soft ceresin wax. No oviposition occurred on the other materials tested (candle wax, a regular ceresin wax, beeswax, and silicone). Significantly (5% level) more eggs were deposited on wax cherries of orange, green, and greenish-yellow colors than black, red, white and blue. A laboratory rearing method employing orange colored wax cherries and an artificial larval diet was established for culturing the western cherry fruit flies.

Ceutorhynchus neglectus Blatchley is a weevil that is native to, and widely distributed in, North America. It has life-history characteristics similar to its alien invasive congener, Ceutorhynchus obstrictus (Marsham), the cabbage seedpod weevil. Our study was undertaken to compare the population structure of C. neglectus in North America to that of C. obstrictus, which, in contrast, was introduced only recently to North America and might be expected to have a simpler population structure. We also compared the population structure of C. neglectus to that of Pissodes strobi (Peck), which is known to possess high levels of intraspecific variation and is also a Nearctic weevil. We sequenced a 790-bp fragment of mtDNA (cytochrome oxidase I (COI) gene) and a 117-bp fragment of nuclear DNA (internal transcribed spacer region 1 (ITS1)). Nested clade analysis inferred contiguous range expansion and restricted gene flow with isolation by distance. Analysis of molecular variance also supported restricted gene flow between geographically distant populations. However, within-species variation in C. neglectus was lower than that for other weevil species including C. obstrictus. We also examined DNA divergences and phylogenetic relationships among 10 species of Ceutorhynchus using parsimony analysis of a 2.3-kb fragment of mtDNA (COI–COII) and a 541-bp fragment of nuclear DNA (elongation factor 1α).

The forest entomologist is often called upon to inspect insect defolialion late in the season at a time when the feeding stage of the defoliator is no longer present in the trees.

Twenty-eight pieces of amber from the Dominican Republic were studied. These pieces, 22–40 million years old, contain 29 cricket specimens as inclusions. Six new species in the Trigonidiidae: Trigonidiinae are described, one in the extant genus Anaxipha (A. dominica) and in three related new genera: Proanaxipha (P. latoca and P. bicolorata), Abanaxipha (A. longispina and A. incongrua), and Grossoxipha (G. yaque). One specimen is described in the Mogoplistidae: Mogoplistinae in the extant genus Ornebius (O. ambericus). The presence of these specimens in amber proves that utilization of the boreal habitat is of long standing. Disparity in the size of the hind legs of one specimen indicates that crickets may once have had the ability to regenerate lost limbs.

Diaeretiella rapae M'Intosh is a cosmopolitan parasitoid of several pest aphid species in agroecosystems, including the Russian what aphid, Diuraphis noxia (Mordvilko) (Mackauer and Stary 1967). In recent years, D. rapae has been imported into the United States from regions throughout the world for D. noxia classical biological control. Knowledge of the alternative hosts of D. rapae could be useful for identifying ecosystems into which the parasitoid could be released at times when D. noxia is absent. Over 30 aphid species are listed as hosts of D. rapae (Mackauer and Stary 1967). This host list, though comprehensive, is a compilation of information gathered from diverse, mostly unrelated sources, and does not necessarily depict the host range of any particular population. Host range differs among populations of some aphidiid species collected from different regions or from different hosts in the same region (Powell 1986). Thus, published host lists can be misleading if they are the sole source of information used to determine acceptable alternative hosts on which to release prospective candidates in classical biocontrol programs. The purpose of this study was to determine the relative suitability of several aphid species common to agricultural and associated non-agricultural ecosystems in the Great Plains as hosts for this Syrian D. rapae isolate in laboratory no-choice tests.

In connection with the study of the pollination of flowers by insects, for several years and in several journals I have published notes on the local Halictinæ, with descriptions of new species and the missing sexes of some which were only known in one sex. This paper is intended to bring my results together in a brief form.

The so-called genus Halictus of authors seems to be altogether too heterogenous. I restore Lasioglossum and propose two other new genera. I think that the several genera must stand or fall together. The venation shows that Agapostemon and Augochlora are more closely related to Halictus, as here limited, than are Lasioglossum, Evylaeus and Chloralictus.

We describe the first dragonflies (Odonata: Anisoptera) from the early Eocene Okanagan Highlands of far-western North America from nine fossils. Six are assigned to five species in four new, named genera of Aeshnidae: Antiquiala snyderaenew genus and species, Idemlinea versatilisnew genus and species, Ypshna brownleeinew genus and species, Ypshna latipennatanew genus and species, and Eoshna thompsonensisnew genus and species; we treat one as Aeshnidae genus A, species A; one is assigned to Gomphidae: Auroradraco eosnew genus and species; and we treat a ninth, fragmentary fossil of unknown family affinity as Anisoptera indeterminate genus A, species A, which represents a seventh genus and eighth species. The dominance of Aeshnidae is consistent with other Paleocene and Eocene fossil localities. Auroradraco eos is the only fossil Gomphidae in the roughly 66-million-year gap between occurrences in mid-Cretaceous Burmese amber and the early Oligocene of France. Ypshna appears close to Parabaissaeshna ejerslevense from the early Eocene Fur Formation of Denmark; this is not surprising given Holarctic intercontinental connections at this time and a growing list of insect taxa shared between the Okanagan Highlands and the Fur Formation.

Studies in Western Canada from 1974 to 1977 on variations in time and duration of the emergence period after diapause of leafcutter bees, Megachile rotundata (Fabricius), reared at latitudes ranging from 49°N to 58°N showed that bees reared at northern latitudes emerged sooner and the duration of the emergence period was shorter than for bees from the southern latitude. When southern bees were reared in the north, their emergence pattern was similar to the northern strain. However, the change of time to emerge and duration of emergence period of northern strains reared in the south was less pronounced. Number of days to emerge varied inversely with length of cold treatment at 4 °C with greater variance in southern strains.