Populations of the chewing louse, Mulcticola macrocephalus (Kellogg) (Phthiraptera: Philopteridae), were investigated on its host the common nighthawk, Chordeiles minor (Forster) (Aves: Caprimulgiformes: Caprimulgidae), from 1992 to 2013 in southern Manitoba, Canada. The louse was present in all but one year with an annual prevalence of 0.52, mean intensity of 16 lice per infested bird, a ratio of 0.81 males and 1.89 nymphs to female (n=178). Intensity was the same in the first 11 and last nine years of the study, but prevalence dropped from 0.59 to 0.34 between the two decades. Population variability for annual abundance, measured as PV, was 0.49. In August, adults and newly fledged nighthawks had a prevalence of infestation similar to the adults that immigrated in the spring, but mean intensity did not reach spring levels until September–October. Samples of hosts were small in some years, reducing the precision of parameter estimates, particularly those based on ratios. The population parameters for M. macrocephalus on a native migrant host were intermediate in the ranges of parameters for four species of lice on non-migratory, introduced feral pigeons, Columba livia Gmelin (Aves: Columbiformes: Columbidae), but the distributions of M. macrocephalus among nighthawks was less severely aggregated than those from pigeons.

Eurasian water milfoil, Myriophyllum spicatum Linnaeus, was introduced into eastern North America late in the nineteenth century. It has spread and developed into a major aquatic weed in many areas of the United states and Canada (Aiken et al. 1979; Reed 1977). In British Columbia, it was first observed in the Vernon Arm of Okanagan Lake in 1970 and had spread to all major 1,akes in the Okanagan Valley by 1976 (Newroth 1979).

The following new species of Deinopsini are described and illustrated: Deinopsis apicicornis (southern USA), Adinopsis cuspidata (Florida, Maryland) and Adinopsis pubescens (Brazil, Colombia, Panama, Mexico). The previously unknown female of Gymnusa campbelli Klim., G. konopackii Klim., and Adinopsis braziliensis Klim., and the male of Metadeinopsis longicornis (Sharp), are described. New distribution and habitat date for some other species of the tribes are added.

While investigating the biology of the North American species of Hypomolyx, field workers in Manitoba found a vestigial, or short-winged, and a long-winged form under apparently identical conditions in about equal numbers. Although biological differences were nor then apparent, there was doubt as to whether they were dealing with one dimorphic species or with two distinct species, A search for morphological characters brought to light numerous differences between the two forms, supporting the view that two species were present. These differences, a description the previously unrecognized species, and notes concerning the status of the genera Hylobius and Hypomolyx are reported below.

The relationship between posttreatment temperatures of 15°, 20°, 25°, and 30°C and toxicity of six pesticides to adult female Phytoseiulus persimilis Athias-Henriot and Tetranychus urticae Koch were studied in the laboratory.

The toxicities of cyhexatin, dicofol, propargite, citrazon, chlorobenzilate, and per-methrin were positively correlated with temperature. Except for propargite and permefhrin, P. persimilis was less susceptible than T. urticae at 15° and 20°C, but equal in susceptibility at 25° and 30°C.

The results obtained may indicate a potential value of posttreatment temperature manipulation as a useful adjunct to integrated pest control programs in glasshouses.

In the summer of 1980, gypsy moth populations were monitored in 13 sparsely infested forests in southwestern Quebec; counts of living and dead larvae and pupae were made on 1,870 trees representing 28 deciduous and one coniferous species. Contrary to our null expectations, the proportionate numbers of pupae compared with larvae on the various host species were not equal. Hosts more preferred by larvae were less preferred by pupae, and vice versa. For example, pupae were disproportionately abundant on host species like Acer pensylvanicum L., Carya ovata (Mill.) K. Koch, and Juglans cinerea L. which are not generally favored larval hosts. Conversely, favored larval hosts like Quercus rubra L. and Ostrya virginiana (Mill.) K. Koch carried lower numbers of pupae than expected from the numbers of larvae feeding on them. Such differential utilization of host trees by larvae versus pupae, which can arise either from host-dependent differences in larval mortality or from late instar migration between hosts, may contribute to maintaining the broad polyphagy of gypsy moth larvae.

Spatial dispersion of potato aphids was studied in fields of processing-tomatoes for 2 years to develop a sequential sampling scheme for the aphid. Potato aphids were found on upper, middle, and lower leaf strata in the percentages 60, 31, and 8. Dispersion was clumped, apterates more so than alates. Among-plant variance was generally greater than within-plant variance. There was a good linear relationship between mean crowding and the population mean and an excellent linear fit between log variance and log mean on all leaf strata for green and pink forms of the aphid and for alates and apterates. The log variance – log mean relationship was used as a basis for sequential sampling.

At the beginning of July 1981 we were informed by plant pathologists conducting disease surveys on canola (= rapeseed) (Brassica campestris L. cvs. Candle, Torch, B. napus L. cvs. Altex, Regent, Tower) in Alberta of the presence of root maggots (Delia spp.) (= Hylemya spp.) in the crop. Although this is not the first observation of this genus infesting canola, no documented account of its geographic distribution or the significance of its damage was available. Canola is an oilseed crop which over the past 10 years has occupied, on average, 1.6 million hectares annually in the three prairie provinces. Therefore, we decided to (a) determine the extent of the damage in Alberta, and (b) collect and rear the insects from infested roots so they could be identified.

The effects of Tomicobia tibialis Ashmead on the reproductive potential of adult Ips pini (Say) females were examined by comparing reproductive indices of parasitized and healthy females maintained in groups of three with healthy males. Parasitized females produced 50% fewer offspring than healthy females, and these offspring were distributed differently in the maternal gallery. Maternal gallery length and larval survival were not significantly different between the two groups, but a statistical power analysis (1 − β) shows this result to be equivocal. The potential to use T. tibialis as a biocontrol agent against I. pini is discussed.

The effects on carabids of natural, fescue, and rye sod types and of tillage were investigated in a pest management apple orchard. Carabids were sampled before and after the treatments by pitfall trapping and by two types of soil sampling. There were no significant effects of sod type on pitfall trap catches; however the abundance of all common species in soil samples was significantly affected by sod types. Usually in soil samples carabids were most abundant in natural sod and least abundant in tilled plots; numbers were intermediate in fescue and rye. Sod type did not affect structure or diversity of the carabid fauna.

A series of samples of the twospotted spider mite, Tetranychus urticae Koch, from 16 experimental populations on “Totem” strawberry, Fragaria × ananassa Duch., were examined to determine the index of dispersion, the variance–mean relationship, the distribution, and the relationship between the mean number of T. urticae/leaflet and the proportion of leaflets without T. urticae. The slope of the variance–mean relationship, 1.64 ± 0.0355(SE), did not differ between sample dates but the intercept decreased significantly (p < 0.01) from 2.56 ± 0.0969 before harvest to 1.76 ± 0.140 during harvest. At 0.0136 T. urticae/leaflet before harvest and 0.0644 T. urticae/leaflet during harvest, the variance equaled the mean, implying that at these densities the data followed the Poisson distribution. Above these densities the data were overdispersed, most samples conforming with the negative binomial distribution but some tending towards greater dispersion than the negative binomial. There was no common k for the negative binomial nor did the data fit the expectation for 1/k that was consistent with the variance–mean relationship. A distribution-free sampling scheme based on the sample mean and the proportion of leaflets without T. urticae () was developed. Tetranychus urticae density can be quickly determined in the field using the naked eye, by iteratively observing leaflets for the presence or absence of T. urticae and referring to a small table that gives both the mean density for a given and the number of leaflets required to obtain a specified standard error.

The ochrogaster group of the genus Euxoa is defined on the basis of genitalic characters, and a new species closely related to Euxoa ochrogaster (Guenée) is described from the Yukon and western Northwest Territories of Canada.

The solitary, pupal parasitoids Spalangia spp. Muscidifurax raptor oviposited supernumerary eggs on house-fly pupae exposed at 3 poultry farms in north central Florida. The percentage total parasitoidism at the 3 sites was 23.7%, 33.6%, and 77.5%, while the percentage of the hosts containing supernumerary parasitoids was 6.2%, 10.7%, and 55.8%, respectively. The average number of parasitoids found per parasitoidized pupa ranged from 1.45 to 2.96. The parasitoids did not show a density-dependent response to spatial variation in host density. Among aggregates of hosts that contained at least 1 parasitoid, percentage total parasitoidism either decreased as host density increased or was unrelated to host density. When total parasitoidism was low, females tended to avoid already parasitoidized hosts. When total parasitoidism was high, more of the hosts contained multiple parasitoids than a single parasitoid.

The relative diapause intensity of a French univoltine and Saskatchewan commercial strain of the alfalfa leafcutting bee, Megachile rotundata (Fab.), was evaluated over a 3-year period. Prepupae from both strains underwent diapause development at 10 °C for different time periods. Diapause intensity was estimated by scoring days to emergence after initiating incubation at three different times in each of the 3 years: fall incubation (immediate post harvest); winter incubation; and spring incubation. In all comparisons made, the univoltine strain had a significantly increased diapause intensity compared with the commercial strain. We concluded that diapause intensity was heritable and that this stable difference between strains could provide the basis for a selected line with increased univoltinism under field conditions.

The relationship between the density of insect holes in the bark (X1) and the density of emerged mountain pine beetles (Y) was investigated in naturally infested lodgepole pine in south-central British Columbia. The density of exit and ventilation holes (Ho) that were present in the bark prior to emergence by mountain pine beetle averaged 10% of all holes present following the emergence period. There was a weak but significant inverse relationship between Ho and both phloem thickness and density of emerged mountain pine beetles. Painting the bark with light-color latex paint did not affect survival or the temporal pattern of emergence by mountain pine beetle but ensured identification and greatly enhanced counting of fresh exit holes. Of the several regression models investigated, the relation between Y and both X1 and X2 (= X1 – Ho) was best fitted by a log-log linear model. A method is suggested for setting limits on the size of exit holes cut by mountain pine beetle in order to exclude from X2 much of the variation caused by exit holes cut by associated insects. A simple mathematical model was developed of the relationship between mean density of exit holes and the density of emerged mountain pine beetles.

Field studies enabled the identification of some limiting factors to which parasitoids were exposed in exploiting the sawfly host, Neodiprion swainei Middleton, and aspects of their quantitative and qualitative impact on the host population. Emergence patterns and flight activity of parasitoids in the spring indicated that larval parasitoids were vulnerable to hyperparasitism by cocoon parasitoids. Although cocoon parasitoids were limited by a shortage of time in which to exploit the host in the spring they still reduced the overwintered host population by 66% in 1969. All forms of predation caused less than 10% sawfly mortality so parasitoids formed the major mortality factor in the spring. Sawfly in prolonged diapause appeared to be immune from cocoon parasitoid attack and thereby efficiency of these parasitoids was limited. However, cocoon parasitoid activity was selective on sawfly that would normally have emerged early in the season and thus delayed the average development of the host population. The complex food web based on the sawfly host provided a sensitive buffering mechanism to produce a degree of stability in the host–parasitoid interaction. The composition of the parasitoid faunae before and after establishment in N. swainei populations of the introduced Pleolophus basizonus (Gravenhorst) indicates the rapidity with which the parasitoid became influential in the complex.

The 26 North and Central American species of Thraulodes are discussed, and synonymies and other pertinent data are presented for all species. On the basis of nymphal gill characters two groups of related species are recognized. Thraulodes brunneus, T. speciosus, T. sp. A, T. sp. B, and T. sp. G are included in the brunneus-group, and T. gonzalesi, T. lunatus, T. packeri, T. salinus. T. zonalis, T. sp. C, T. sp. D. T. sp. E, and T. sp. F form the gonzalesi-group, The 14 species of nymphs are included in an illustrated key and on distribution maps, and the account of each includes complete synonymy, nymphal description, and collection records. Nymphs designated as Thraulodes spp. A, B, C, D, E, F, and G are described, and new descriptions are presented for nymphs of T. packeri and T. zonalis.

The amount of damage to apples caused by the bugs Atractotomus mali (Meyer) and Campylomma verbasci (Meyer) is largely related to the density of the bug population and to the apple variety. Bug numbers can be reliably measured by a ’hatching’ method, and preventative insurance spraying can be avoided where indicated.

A procedure is described for obtaining free eggs and first-stage larvae of Sitophilus granarius (L.) and rearing the larvae to the adult stage on whole wheat, corn, and rice flours and on diet 2, a casein–starch-based meridic diet.

Larval growth rates of males and females reared at 29 °C and 65% R.H. on whole wheat flour were comparable although males attained a higher maximum mean weight. Days to 50% adult emergence (eclosion) were 25.5 and 26.5 for females and males, respectively.

Larval growth rates on whole wheat flour were comparable with those on whole corn flour but were better than the rates obtained on whole rice flour; however, growth on diet 2 was improved compared with that on whole wheat flour. The mean weights of 14-day-old larvae were 2.51 ±.40 mg and 1.25 ±.16 mg for those reared on diet 2 and wheat flour, respectively. Similarly, survival to the adult stage was slightly greater (79%) on diet 2 than on wheat (70%). On diet 1, a casein–glucose-based meridic diet, no larvae developed to the pupal stage.

Breeding sites for Simulium venustum, Simulium arcticum, Simulium pugetense, Simulium hunteri, Simulium canadense, and Simulium decorum were found in the Vancouver area. Addition of juvenile hormone analogues to the rearing water of S. decorum resulted in virtually complete inhibition of adult emergence.