Promoresia elegans (LeConte), Optioservus fastiditus (LeConte), and Stenelmis nr. bicarinata LeConte coexist in Duffin Creek, Ont., making up 3.78–23.92% of the riffle fauna present.

Promoresia elegans and O. fastiditus appeared to have semi-voltine life histories. Stenelmis nr. bicarinata appeared to be univoltine but with overlapping generations and slow recruitment occurring from late summer to fall; growth was slow in winter but fast in spring and summer.

Based on the index of relative importance (Pinkas et al. 1971), detritus was identified as the most important food source for all size classes and all species throughout the year. Microinorganics ranked second, with diatoms, fungal hyphae, and vascular plant material being the least important food sources. There was no indication of ontogenic food switching in any of the species.

The Schoener (1970) niche overlap index indicated almost complete dietary overlap (Cxy = 0.78–0.97) among the three species throughout the year and the Hurlbert (1978) niche overlap index similarly indicated a convergence of diets (L = 1.31–3.54).

Niche breadth values were found to be high for all species on the rock surfaces (generalist diet) but were lower in the hyporheic zone indicating a higher degree of specialization there.

The orientation of Aedes aegypti in an upward or downward vertical air current was studied. The vertical movements of A. aegypti which have been activated by CO2 are always against the air flow and toward the inlet end, where the insects alight and probe. With sufficient illumination A. aegypti locate an invisible artificial host whether it is at the top with air moving down or at the bottom with air moving up. They do not attempt to locate a visible, black, artificial host placed downstream. Body attitude is similar in upward or downward air flow. The mosquitoes follow the vertical movement of a surrounding spiral stripe pattern, whether stripe movement is upward or downward, whether air is still or moving vertically with or against the stripes. They will not fly against stripe movement to reach an upstream host, real or artificial. Repellent vapor destroys the upstream orientation when air flow is vertical but not when the flow is horizontal. The stripe-following action is not affected by repellent. The experiments indicate that A. aegypti possesses a vertical-air-speed sensor, of a mechanical type, to direct movement up or down in a vertical air stream. The cybernetic system must be complex and requires cooperative use of mechanical and optical sensory information channels. The initial action of repellent vapor appears to be peripheral rather than central to the nervous system, and to affect only the mechano-, chemo-, and thermo-receptors.

The widely occurring fungal genus Lecanicillium Zare & W. Gams (formerly Verticillium) includes species that are pathogenic to insects. We collected 27 Lecanicillium isolates from soil and from dead adult Pissodes strobi (Peck) in British Columbia, Canada, and assessed their virulence against this host. Eighteen isolates were identified as L. longisporum (Petch) Zare & W. Gams and six as L. muscarium (Petch) Zare & W. Gams, while three isolates could not be identified to the species level. We assayed a subset of these isolates (14 L. longisporum, 3 L. muscarium, and 1 Lecanicillium sp.) as well as the fungal component of the commercial products Mycotal® (L. muscarium) and Vertalec® (L. longisporum) and a herbarium isolate (Lecanicillium sp.). When adult weevils were inoculated with a conidial suspension (1 × 107 conidia/mL), mycosis-related mortality at the end of a 17-day incubation period varied between 20% and 100%, depending on the isolate tested. Eight of the isolates killed >75% of weevils: a Lecanicillium sp. isolate, PFC19, which displayed the lowest LT50 value; five indigenous L. longisporum isolates; and both commercial products. In a goodness-of-fit test comparing isolate virulence among species, the unidentified PFC19 isolate was found to be more effective than either L. longisporum or L. muscarium, while L. longisporum caused somewhat greater mortality than L. muscarium. In a similar analysis, isolates extracted from soils tended to be more effective than those obtained from cadavers. Horizontal transmission to live P. strobi was observed using different isolates of Lecanicillium species. Notwithstanding the variability in virulence, the indigenous Lecanicillium species that we isolated and assayed are confirmed as pathogenic to P. strobi in British Columbia.

Pupal diapause in Athrycia cinerea (Coq.), a larval parasite of bertha armyworm, Mamestra configurata Walk., was usually prevented if the parasite larvae were reared at 25°C, but not if they were reared at 20°C. Mature larvae of the parasite were more sensitive than younger larvae to this temperature effect. Diapause incidence in A. cinerea at 20°C was not reduced by using only young parent females for oviposition; by rearing the parent females at a high temperature (25°C) and long day (16 h) prior to and during oviposition; by using host larvae that had been light-programmed for non-diapause; or by increasing the photoperiod, to which the parasite larvae were exposed, from 12 to 16 h. Termination of pupal diapause was accelerated by low temperature; at least 24 weeks at 2 °C were required to synchronize adult emergence.

In biological monitoring, deploying an effective standardised quantitative sampling method, optimised by trap design and sampling effort, is an essential consideration. To exemplify this using dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae and Aphodiinae) communities, three pitfall trap designs (un-baited (TN), baited at ground level (flat trap, TF), and baited above the trap (hanging trap, TH)), employed with varying levels of sampling effort (number of traps=1, 2, 3 … 10; number of days=1, 2, 3), were evaluated for sampling completeness and efficiency in the Eastern Cape, South Africa. Modelling and resampling simulation approaches were used to suggest optimal sampling protocols across environmentally diverse sites. Overall, TF recovered the greatest abundance and species richness of dung beetles, but behavioural guilds showed conflicting trends: endocoprids preferred TH while paracoprids and telocoprids preferred TF. Resampling simulation of trap type and the two components of sampling effort suggested that six TF traps left for three days was most efficient in obtaining a representative sample and allowed differentiation between trap types, allowing the improved efficiency to be recognised. The effect of trap type on non-target specimens, particularly ants, was also investigated. TF and TH caught almost no by-catch, which is ethically desirable.

Pitch canker of pines (Pinus spp.) and Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) (Pinaceae) is caused by the fungus Fusarium circinatum Nirenberg et O'Donnell. In California, infections by F. circinatum occur largely through wounds caused by insects. Field experiments were initiated to determine whether the colonization activities of twig beetles, Pityophthorus spp. (Coleoptera: Scolytidae), could explain the incidence of pitch canker on Monterey pine (P. radiata D. Don), Bishop pine (P. muricata D. Don), ponderosa pine (P. ponderosa var. ponderosa Dougl.), knobcone pine (P. attenuata Lemm.), and Douglas-fir. Asymptomatic branches were cut from each of four pairs of tree species (Monterey–Bishop, Monterey–ponderosa, Monterey–knobcone, Monterey–Douglas-fir) at four sites and attached to the lower canopy of both heterospecific and conspecific host trees (total of four combinations per pair). After 10 weeks, branches were collected and placed in rearing tubes in the laboratory. Emerging insects were identified and placed on a Fusarium-selective medium. Monterey, Bishop, and ponderosa pines were more heavily infested by Pityophthorus spp. than Douglas-fir and knobcone pine. Furthermore, more Pityophthorus beetles emerged from Monterey pine branches placed in Monterey pine canopies than from Monterey pine branches placed in Bishop or ponderosa pine canopies, indicating that reduced emergence (colonization) was caused by the hetero specific host. Relatively fewer insects emerged from sites containing either Monterey and knobcone pines or Monterey pine and Douglas-fir. Fusarium circinatum was not isolated from emerging Pityophthorus spp. Susceptibility of the five host species, based on mean lesion lengths resulting from mechanical inoculations, varied significantly. The longest lesions were on Monterey pine and the shortest were on ponderosa pine and Douglas-fir. The low incidence of pitch canker on Douglas-fir and ponderosa pine in nature compared with that on Monterey, Bishop, and knobcone pines may be explained by the low colonization by twig beetles and the greater resistance of Douglas-fir and ponderosa pine to this disease, compared with the other three hosts.

The relative concentration of elements in adults of the red turnip beetle, Entomoscelis americana Brown, as determined by X-ray energy-dispersive spectroscopy (XES), was used with discriminant analysis to identify source populations of beetles from different fields in the same district. Classification of dispersed beetles from the same district, using discriminant functions, suggests that XES is a promising technique for dispersal studies. However, multivariate analysis of variance and canonical analysis of XES results of groups of beetles given different foods over varying times in the laboratory indicate that highly significant changes occur in the chemoprint. Methods of minimizing the effect of such changes are suggested for future studies of dispersal.

The 40 known species of the genus Xysticus C. L. Koch that occur in Canada are described and illustrated. Keys to both sexes are provided. Three new species, X. ampullatus, X. leechi, and X. winnipegensis, are described, two species, X. lutulentus Gertsch and X. nicholsi Gertsch, are synonymized with previously described ones, and two, X. ellipticus new name and X. alboniger new name, are transferred to Xysticus from another genus.

Logging slash constitutes an environment supporting a particular association of insects and other arthropods. At first, the species in the community are governed by the character of the slash, but with the passage of time the condition of the slash changes, the rate of change being directly affected by bark beetles and other wood borers that facilitate entry of wood-destroying fungi. As the environment changes, those species for which the habitat is no longer suitable drop out, leaving in the association only those that can exist under the new conditions. Insect communities in slash, logs, and dying trees have been studied by Hopkins (1893, 1899), Clemens (1916), Blackman and Stage (1918, 1924), Graham (1925), DeLeon (1934), Beal and Massey (1945), Howden and Vogt (1951), and others. The succession of communities of animals inhabiting slash, logs, and dying and dead trees has been shown by Adams (1915) and Savely (1939) to continue until the wood has disintegrated completely.

In an earlier paper (Syme and Davies, 1958), three new species in the hirtipes-complex (Prosimulium fuscum Syme and Davies, P. mixtum Syme and Davies and P. fontanum Syme and Davies) were described, compared with related species in other parts of the world, and their known distribution in northeastern North America indicated. In this paper are presented observations on the manner and dates of oviposition, on incubation, on the larval feeding, on the rate of larval growth during the fall and winter in a spring-fed stream, and on differences in habitat and seasonal emergence of the three new species.

Baronia brevicornis Salvin (Lepidoptera: Papilionidae) is one of the most enigmatic butterflies in the world and possibly represents the most ancient lineage among the superfamily Papilionoidea. Its geographic distribution is remote from that of all its potential close relatives and many of its biological and ecological characteristics are unique among the suborder Rhopalocera. One of its particularities is that the occurrence plots of this species seem to be independent, each representing individual populations, despite the fact that the host plant: Acacia cochliacantha Humboldt and Bonpland ex Willdenow (Fabaceae), is one of the most common Mexican Fabaceae species. Our results show that no B. brevicornis populations occur if the host plant does not cover at least two-thirds of the locality. Even in the most favourable zones, the landscape occupancy of the butterfly does not exceed 2.5% of the available habitat even when its host plant covers 50% of the area. The average density of adults was 840 individuals/ha in favourable habitats, frequently on areas of around 3 ha, below of 1400 m. Using the BIOMOD2 package and the largest available set of abiotic conditions for Mexico implemented in the WorldClim database, we propose a revised potential distribution and discuss the results of our model with field occurrence data. Evolutionary and conservation issues are discussed in the light of our results.

The artificial feeding of aphids has received renewed attention in recent years and many attempts met with limited success. Maltais (1952) reported on a simple apparatus for feeding aphids aseptically on chemically defined diets. At the time, several investigators on the artificial feeding of homopterous insects had succeeded in getting the insects to feed temporarily on special food mixtures through different types of membranes, but the insects had neither grown nor reproduced.

Survival of Adalia bipunctata (L.) emerging from eggs laid some distance from prey locations, depended on the ability or the larvae to reach a prey location on a host plant. Distances between egg clusters and prey locations, when less than 63 cm in laboratory cages, had little effect on larval survival. Pathways used by a larva to prey was more important than distance. Larvae that had access to prey via pathways, reached prey as distant as 63 cm from eclosion sites.Cannibalistic predation by these larvae on eggs increases their survival chances when prey are scarce.

The populations of Spilonota ocellana (D.&S.) on two cultivars in an insecticide free orchard showed nearly identical trends over a 12-year period. Egg populations reached maximum numbers when the orchard was 9 years old and the ensuing larvae infested 33% of the clusters the following year. A marked decline in all stages occurred when the orchard was 11 to 12 years old and this was immediately followed by a second peak of less intensity on both cultivars. The only difference in mortality of the population on the two cultivars was found in neonate larvae. The average survival of egg to pupa for the 12-year period was near 7%.

The pine needle scale is a serious pest of spruce and pine in shelter-belt and ornamental plantings in the agricultural region of the Prairie Provinces of Canada. The present study was made to provide accurate data on the life cycle, habits, and seasonal development of the pine needle scale in this region. This information is essential for investigations of artificial control.

Observations were made at Indian Head, Sask., in 1947. The populations sampled were on Scotch pine in a shelter belt and white spruce in an ornamental planting. Other populations were sampled when further information was required.

Unfed forest tent caterpillar (Malacosoma disstria Hbn.) larvae were subjected to temperature treatments of −18°, −12°, −7°, −1°, 4°, and 22 °C, each at durations of 2 days, 7 days, and 14 days. Each temperature–duration treatment was initiated 3 days before expected hatch, and 3 days after hatch. Fed larvae were subjected to identical treatments 2 days after hatch. Temperature treatments of the before hatch group resulted in appreciable mortality only at −18 °C for 7 days and at −18 °C and −12 °C for 14 days. Temperature treatments of the after hatch group resulted in nearly 100% mortality at −18 °C for all durations, at −12 °C for 14 days, and about 50% mortality at −7 °C for 14 days. Other temperature–duration combinations caused little mortality. The mortality resulting from temperature treatments of fed larvae did not differ from unfed larvae of the after hatch group.

Microctonus stelleri Loan is described as a new species. This euphorine braconid occurs in France, Germany, Sweden, and Russia. It is umvoltine and its only known host is the alfalfa weevil, Hypera postica (Gyllenhal). In the spring the mature parasite larva issues from the overwintered adult host and forms a white cocoon in the ground litter. In about 2 weeks the adult parasite emerges, mates, and oviposits in larva of the alfalfa weevil. The parasite egg hatches and the first-instar larva remains within the host until the following spring. In northern France M. stelleri was the dominant parasite in overwintering adults of H. postica. Parasitism ranged from 0 to 13% though it was usually less than 6%. Laboratory studies showed that M. stelleri females live longer, have a higher rate of oviposition, and parasitize more hosts than females of M. colesi Drea, a parasite of the weevil in the United Slates. A technique is described for the recovery of M. stelleri from adult alfalfa weevils. From 1966 to 1970, 4387 parasites were imported from France and released at 24 localities in the United States.

The cinnabar moth, Tyria jacobaeae L., was established in the Atlantic provinces and British Columbia for the control of tansy ragwort. Establishment was difficult to obtain with imported stock: only two of 14 colonies survived, one on each coast. The rate of survival in these colonies increased with succeeding generations, and with stock from the regional colony eight of nine releases became established in Nova Scotia. Most of the established colonies increased until the ragwort was defoliated.

The chordotonal organs of insects and especially those of the Acrididae are well known. Slifer (1936) lists 76 scoloparia which are distrilluted throughout the body of Melanoplus differentialis. Although the sense organs of Melanoplus mexicanus described in this study are, in general, similar to thnse found by Slifer, her summary account would seem to warrant a more detaited consideration of their structure.

The organ of Johnston in the second segment of the antenna is included because of its structural similarity to the chordotonal organs, although it is usually considered to have a special sensory functinn distinct from that of the chordotonal type.

The suitability of three potential host plants, Solidago canadensis L. var. canadensis (Asteraceae), Solidago graminifolia (L.) Salisb., and Aster lateriflorus L. (Asteraceae), for the goldenrod beetle, Trirhabda virgata LeConte was determined by measuring several fitness components during the T. virgata life cycle. Neonate larvae were collected from S. canadensis plants and transplanted onto S. canadensis, S. graminifolia, and A. lateriflorus and maintained in field enclosures until the last instar was reached. Once brought into the laboratory, larvae were fed their assigned host plant until pupation. Following emergence, adults were weighed and separated into mating pairs to record oviposition and longevity. Eggs were kept in the laboratory until the following spring, when first instar larvae were taken into the field and re-established on their assigned host, and the experiment was repeated for 2 years. Larval survival and rate of development was not affected by the host plant. Mean weight of adults at emergence was greater on S. canadensis than on either S. graminifolia or A. lateriflorus. Two components of adult fitness, postmating longevity and realized fecundity, were measured. Longevity of adult female T. virgata was not affected by the host plant. Fecundity of T. virgata reared on A. lateriflorus and S. graminifolia was lower than the fecundity of females reared on S. canadensis. These results are consistent with the hypothesis that both intrinsic plant quality and the mobility of the foraging stage are important in the evolution of host range in T. virgata. These experiments were repeated over a 3-year period, using offspring from the survivors of the previous year for the 2nd and 3rd years. Over this time, individuals experienced "laboratory adaptation," and both accepted and increased their performance on previously unacceptable food plants.