Neem seed extract (20, 60, and 180 ppm azadirachtin) applied to the crowns of black spruce trees immediately prior to female reproductive bud flush, resulted in high mortality of early instar spruce budworm larvae. Dose-dependent reductions of 40–93%, as compared with check trees, were observed 2 and 4.5 weeks after treatment. Seed cone protection from grazing damage, however, was moderate; at 60 ppm azadirachtin, the incidence of cone grazing was reduced 29%, and the proportion of severely grazed cones reduced 39%, as compared with check trees. Larval mortality and bud damage observed in the laboratory corroborated field results. High toxicity to second-instar larvae, and performance during adverse weather conditions, supports the potential of neem seed extract for control of spruce budworm defoliation. However, both laboratory and field results indicate that feeding occurs before the effects of neem seed extract manifest, resulting in moderate protection of cones. Whereas foliage can tolerate low levels of feeding, female strobili are damaged significantly. Excellent protection of foliage was achieved from systemic injections of neem seed extract to white and black spruce trees (1.5 g azadirachtin/tree). Neem seed extract, formulated for systemic application, could provide a botanical alternative for control of forest pests in urban environments.

Thanasimus formicarius (L.), a main predator of bark beetles in Eurasia, was studied at constant temperatures of 15, 21, and 25 °C. Morphological data and duration of development are indicated for the egg (2.4 by 0.8 mm; 28–7 days at temperatures from 15 to 25 °C), three larval instars (9–14 days depending on instar and temperatures of 21 and 25 °C), pupa (15 and 33.5 days over the range of temperatures), and adult. Information is also given on head capsule size, sex ratio, fecundity, and length of adult life.

The oviposition preferences of Lygus lineolaris (Palisot de Beauvois) were studied on Brassica carinata A. Braun, Brassica juncea (L.) Czern, Brassica napus L., Brassica rapa L., Sinapis alba L. (high glucosinolates), Sinapis alba L. (low glucosinolates), and Sinapis arvensis L. in a choice test during a 14-day period in field cages. Host-plant discrimination occurred on at least two levels. The first level occurred at the generic level; ovipositing females first selected species of Sinapis on which to lay eggs and later laid on species of Brassica. On species of Sinapis, 80% or more of the total number of eggs were laid during days 1–6, whereas only 35–58% were laid during this period on species of Brassica. The second level occurred at the species level in both Brassica and Sinapis. In Brassica, significantly more eggs were laid on B. carinata and B. napus than on B. juncea; in Sinapis, significantly more eggs were laid on S. alba (high glucosinolates) than on S. arvensis. The numbers of eggs did not differ significantly among B. carinata, B. napus, and S. alba (high glucosinolates). The numbers of eggs on B. rapa and S. alba (low glucosinolate) were not significantly different from those on the other five Brassica and Sinapis hosts tested. Host-plant selection seemed to be unaffected by glucosinolate levels in the seed of S. alba.

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a major worldwide pest of cruciferous vegetables (Talekar and Shelton 1993). Male and female adults of this species can be accurately identified by visible differences in their external genitalia. According to Robertson (1939), the sex of pupae can also be identified, but, in our experience, this approach is more difficult. For some types of research, determination of larval sex would be useful. For example, one could determine sex-specific responses of larvae to a treatment by observing mortality, development rate, or behavior of male and female larvae separately. In studies requiring hybrid mating between different strains of diamondback moth (Tabashnik et al. 1992), one could isolate groups of male larvae separately from female larvae to avoid mating within a strain. Some lepidopteran larvae can be sexed by the gonads being visible through the cuticle of the fifth abdominal segment or by the position of external pits marking the location of the genital discs in the eighth and ninth abdominal segments (Stehr 1987). But, because of their small size, it is not practical to sex diamondback moth larvae by external pits and we have found no studies in which male and female larvae were identified by gonadal form. Herein we report that third- and fourth-instar larvae of diamondback moth can be sexed efficiently and reliably.

The mature larvae of three species of Hoplitis, namely Hoplitis anceyi (Pérez), Hoplitis anthodemnion Michener, and Hoplitis nitidula (Morawitz), are described and compared with the other known larvae in the genus. The morphology of the spiracles, antennal discs, and antennal papillae, the absence of a seta on the mandibular basis, and the shape of the vertex permit the characterization of each species. Furthermore, H. anthodemnion has the integument covered by setiform spicules. Nevertheless, there is no clear separation between the three species studied and those previously known, and larval morphology does not support the consideration of Anthocopa and Hoplitis as separate genera.

The exotic birch-leafmining sawflies Fenusa pusilla (Lepeletier), Profenusa thomsoni (Konow), and Heterarthrus nemoratus (Fallen) occurred in Alberta during 1992–1995, but only the first two were abundant. Birch-leafmining sawflies occurred at all sites surveyed in central and southern Alberta, and appeared to be expanding their ranges northward. Adult F. pusilla began emerging in mid-May (approximately 220 DD05), and there were one to three generations per year, depending on location and year. Female F. pusilla were relatively less abundant on young than on mature trees. Profenusa thomsoni began attacking trees in June (between 400 and 550 DD05), and was invariably univoltine. Both species were more abundant and were active earlier on urban trees than at a nearby rural location. The highest catches and most complete representations of seasonal activity were obtained using yellow sticky traps. Larval F. pusilla and P. thomsoni are unlikely to compete directly for leaf resources because their leafmining activities are separated spatially and temporally, but they probably compete intraspecifically.

Aphodius hyxos Petrovitz, 1962 was reared in the laboratory and the third-stage larva is described and illustrated. The third-stage larvae and life histories of Aphodius granarius (L.), 1767 and A. hyxos are compared. Adults of A. hyxos are active from late autumn until early spring, whereas adults of A. granarius are active chiefly from early spring to late summer. The larvae of both species may be separated by differences in the distribution of setae on the raster, the shape of the anal lobes, and the size and number of holes in the respiratory plate.

Cylas formicarius (F.) shows a strong overall sexual monomorophism, with external differences noted in only three organs: (a) relative size of the hind wings; (b) form of the antennal club and numbers of its different types of sensillum; and (c) size of the compound eyes and their individual facets. We relate these to known or predicted behavioural differences. Eye dimorphism is used to test a theoretical rule on the relationship between differences in overall eye size and in the size of individual ommatidia. Some sexually monomorphic features are briefly discussed, including two types of putatively sensory hairs not found on the antennae.

Trials using four different sex combinations of Colorado potato beetle, Leptinotarsa decemlineata Say, demonstrated that male beetles move upwind towards females, whereas no attraction was seen between any of the other combinations. Attraction was not found to increase significantly after the female reached 10 days old. Visual stimuli appear to be unimportant from a distance of 50 cm. Orientation behaviour by the male beetle was observed as it walked upwind towards the female; no identifiable calling behaviour by the female was observed. The data indicate a sex pheromone is being produced by the female and is used by the male for mate location from a distance.

Seasonal abundance of Sitobion avenae (F.) and Rhopalosiphum padi (L.) was monitored in Nova Scotia winter wheat plots. Rhopalosiphum padi was the more common aphid species during "heading out." Winter wheat cultivars differed in their resistance to R. padi development; the highest reproductive rate was on ’Absolvent.’ The effect of chemicals used in intensive cereal management on R. padi and Coccinella septempunctata (L.) was assessed. Dimethoate and carbaryl caused similar high mortality to both insects, but pirimicarb was more toxic to the aphid than to its predator. Over a 2-year period, field plots that received regular pirimicarb treatments for selective aphid control early in the growing season showed a 9% increase in wheat yield, compared with the checks and plots that received carbaryl. Wheat yield increased 18% when pirimicarb was used later in the season; when applied in both periods, pirimicarb gave a total yield increase of nearly 30%. Late applications of carbaryl alone, or in combination with pirimicarb, increased yields by only 9% over the controls. Half of the yield increase (18% vs. 9%) with late season control by pirimicarb was lost with the addition of carbaryl, which minimized the C. septempunctata population for nonselective insect control. Rhopalosiphum padi numbers from June 20 to July 15 had the greatest impact on yield in these plots, and natural control agents including C. septempunctata accounted for a 9% increase in yield.

Searching and ovipositional behaviors by female Eretmocems sp. nr. californicus Howard on Bemisia argentifolii Bellows and Perring infesting velvetleaf, Abutilon theophrasti Medic. (Malavaceae), and telegraph weed, Heterotheca grandiflora Nutt. (Asteraceae), were quantified. Adult female behaviors were described and quantified for E. sp. nr. californicus to establish a behavioral time budget analysis. Females departed from leaves of A. theophrasti in 83.3% of the trials, and of those that remained and searched for hosts, walking speeds averaged 0.29 mm/s. Females departed from the leaves of H. grandiflora in 44.4% of the trials, and those remaining readily searched for whitefly hosts with walking speeds averaging 0.26 mm/s. The duration of host assessment by antennation was related to subsequent behaviors; rejecting a host was a shorter process than accepting it for further evaluation irrespective of plant species or nymphal stage. Evidence for a behavioral preference for oviposition under early nymphal instars was documented for female E. sp. nr. californicus on both plant species. Oviposition efficiency in 1-h laboratory trials for nymphs on A. theophrasti was 30% and efficiency on H. grandiflora was 23%. Females spent 61.9 and 53.3% of their total time in searching, host assessment, probing, and oviposition while on A. theophrasti and H. grandiflora, respectively. The remainder of the time was spent grooming, resting, and host feeding, except host feeding on A. theophrasti was not observed. Implications of this study for silverleaf whitefly management through conservation and augmentation of native flora and fauna are discussed.

Below-ground herbivores have been poorly studied regardless of their importance for the establishment and composition of plant communities. In a subalpine grassland associated with a 3200-m-elevation pine forest in central Mexico, the composition and vertical and horizontal distribution of the macroarthropod root-feeding community was studied for 14 months. The root-feeding community included six species of Coleoptera and one species of Diptera. The dominant species were Phyllophaga spp. (subgenus Phytallus, "macrophylla" group) and Trachyploeomimus aff. spurcus Champion. Mean density and biomass of this community were 101 individuals and 3 g per square metre, respectively. These values were low when compared with those reported for other communities. Species were most abundant in the first 10 cm of the soil all year around. Dominant species showed a clumped horizontal distribution most of the year.

Black flies (Diptera: Simuliidae) were collected from a tamarack stand, Larix laricina (Du Roi) Koch, heavily infested with Adelges lariciatus (Patch) (Homoptera: Adelgidae). Insect nets were used to sweep the tamarack branches to capture black flies associated with the trees. Six black fly species were sweep-netted, with 85.5% of all flies belonging to Simulium venustum Say complex. Samples of honeydew and the crops and midguts of individual black flies were tested by thin layer chromatography using fructose, glucose, sucrose, turanose, melezitose, raffinose, and stachyose as standards. The sugars fructose, glucose, sucrose, raffinose, and stachyose were found in the adelgid honeydew samples. Of the 201 black flies tested, 194 contained sugars, which occurred in 16 combinations. It is argued that stachyose can be used to indicate when black flies have fed on the adelgid honeydew. We conclude that 49.7% of the S. venustum collected from the tamarack had fed recently on this honeydew source. In addition, it was observed that black flies reared in the laboratory readily ingested freshly excreted and older (dry) honeydew when presented with branches from the tamarack stand.

Visual responses of adults of Calosoma sycophanta L., which are predators of the gypsy moth, Lymantria dispar L. (Lepidoptera: Lymantriidae), were investigated in laboratory arenas. Beetles moved toward dark cylinders significantly faster than to light ones when the background was white, but no differently when the background was black. Thus, C. sycophanta appears to respond most readily to dark objects, and this response is only slightly modified by contrast with the background. Beetles move toward large-diameter black cylinders more readily than toward small-diameter ones, but object height and shape do not appear to be important characteristics. The visual responses of C. sycophanta would tend to orient adults toward the base of trees in a forest. Because beetles prey on gypsy moth larvae in trees, this orientation serves to position them where they can most readily find hosts, or perhaps to guide them to objects under which to hide.

A 5-year study of the black flies of east-central Saskatchewan revealed 21 species, including Simulium incognitum sp.nov. Chromosomal and ecological evidence for reproductive isolation is presented for this new species, formerly known as S. venustum Say CC4, and S. venustum Say CC. All 21 species in the study are associated with productive streams and rivers. As many as nine of these species might comprise the pest assemblage harassing livestock. The major pest, S. luggeri Nicholson and Mickel, is cytologically distinct from populations in the eastern United States on the basis of a two-step, Y-linked inversion in the IIS chromosomal arm. Simulium luggeri is the only livestock pest that breeds almost solely in large streams and rivers. The other eight probable pests breed entirely or partly in streams less than 10 m wide, often below beaver dams, suggesting that management efforts should specifically target these sites.

Blanchardia gen.nov. and its type species Blanchardia poikila sp.nov. are described and the new combination Blanchardia capitophoroides is established for Macrosiphum capitophoroides Blanchard, 1944. The new genus forms part of the Macrosiphum group and it is characterized by the presence of one to three poorly defined rows of cells on the apex of siphunculus. Both species live on Senecio in Patagonia, Mendoza Province, Argentina.

A new genus and species of grylline cricket are described from Baja California, Mexico. This cricket, unlike most others, is reddish in colour.

Ingestion of 0.1 μg of RH-5992, tebufenozide, by early 6th instar larvae of the spruce budworm, Choristoneura fumiferana (Clem.), prior to the appearance of the ecdysone peak in the hemolymph, resulted in the induction of a precocious incomplete moult that was lethal. The larvae stopped feeding within 8 h post ingestion and remained quiescent just as they do in preparation for a normal moult. Head capsule slippage started at 12 h post ingestion, became pronounced by 24 h, and by 48 h an untanned new head capsule was visible behind the old one. The lack of tanning of the new cuticle was due to the failure of dopadecarboxylase gene expression. Although the old cuticle was loose around the entire body, indicating that apolysis had occurred, there was no evidence of ecdysis of the old cuticle, suggesting that eclosion hormone was probably not released. Earlier instars required a lower dose than the later ones to elicit an "all or none" type of moulting response. The most effective routes of entry were by intrahemocoelic injection, followed by ingestion. Topical application was effective only when nonaqueous carriers such as acetone or dimethyl sulfoxide were used. The larvae were unable to discriminate between treated and untreated diet over a 48-h period. The transcription factor, Choristoneura hormone receptor 3, which is normally expressed at the onset of the hemolymph ecdysone peak, was expressed in the epidermis 1 h post ingestion of RH-5992, reached a peak level by 3 h, and became undetectable by 24 h, confirming that this analogue acts through the ecdysone receptor system. Greenhouse tests using potted white spruce trees sprayed with RH-5992 and colonized with 4th-instar spruce budworm indicated that field dosages of 35, 70, 140, and 280 g/ha would all be effective. Ground spray trials conducted in a spruce budworm infested white spruce stand in Zee Casault, Gaspé, Quebec, using a backpack sprayer showed that ≥ 70 g/ha of RH-5992 reduced the insect population by 100% with very little defoliation and was better than Chlorfluazuron® (an analogue of the chitin synthesis inhibitor, diflubenzuron or Dimilin®) treatment, which was used as a positive control. The unique mode of action of this ecdysone agonist and its effectiveness as an environmentally benign control agent for the spruce budworm are discussed.

Cryptolestes ferrugineus (Stephens), Cryptolestes pusillus (Schönherr), Tribolium castaneum (Herbst), and Rhyzopertha dominica (Fabricius) were gradually exposed to falling temperatures in the laboratory, simulating conditions in the centre of a 12- or 6-m-diameter granary containing wheat. Two years of overwintering mortality for C. ferrugineus and R. dominica were obtained from 11–13 farm granaries (40–100 t wheat). Cryptolestes ferrugineus (adults) was the most cold hardy species among the beetles tested. In the laboratory, survival was 40% at 25 °C declining to 10 °C over10 months, whereas at 25 °C declining to 0 °C over 10 months survival was 7%. Cryptolestes pusillus and T. castaneum did not survive once temperatures were below 10 °C, and R. dominica adults did not survive temperatures below 3 °C. In the field, there was no survival of C. ferrugineus in granaries that had February temperatures of −6.7 °C or lower. Six-week exposure to −10 °C killed most C. ferrugineus adults taken from granaries in February. Cryptolestes ferrugineus caught in granaries were more cold hardy than laboratory-reared strains. No T. castaneum or R. dominica survived an entire winter in granaries in the 2 years tested. Although C. pusillus was not tested in the granaries, it is unlikely it could survive the winter, as it had the same level of cold tolerance as T. castaneum in the laboratory. The implications for the population dynamics of these pest species in prairie grain are discussed.

Strains of workers that were high or low in their retinue attraction response to queen mandibular pheromone (QMP) in a laboratory bioassay were fostered in queenless colonies to measure their differential queen-rearing behaviors. High-strain workers spent proportionately more time working on and in queen cells than low-strain workers, and there were significant age by strain effects for time spent rearing queen cells. No interindividual differences were detected among the strains in the tendency to rear queens. Results from this experiment suggest that QMP retinue attraction response may be a mechanism upon which selection acts for division of queen-rearing labor.