Lygromma anops sp. nov. (Gnaphosidae, Araneae) is described from lava tubes on Isla Santa Cruz, Galápagos, Ecuador. The species appears to have no known close relatives in the Galápagos Islands or on the South American mainland.

A distributed delay age structure model is presented for plants and insects that describes the dynamics of per capita energy (dry matter) acquisition and allocation patterns, and the within-organism subunit (e.g. leaves, fruit, ova) number dynamics that occur during growth, reproduction, and development. Four species of plants (common bean, cassava, cotton, and tomato) and two species of insects (pea aphid and a ladybird beetle) are modeled. A common acquisition (i.e. functional response) submodel is used to estimate the daily photosynthetic rates in plants and consumption rates in pea aphid and the ladybird beetle. The focus of this work is to capture the essence of the common attributes between trophic levels across this wide range of taxa. The models are compared with field or laboratory data. A hypothesis is proposed for the observed patterns of reproduction in pea aphid and in a ladybird beetle.

Spring-felled logs of Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, and western hemlock, Tsuga heterophylla (Raf.) Sarg., were attacked by ambrosia beetles, Trypodendron lineatum (Oliv.), in the year after felling. By monitoring individual galleries it was determined that brood production was similar to that found in fall- and winter-felled logs. The sex ratio of the brood did not differ significantly from 1:1. Only beetles that had failed to establish successful galleries emerged during the "second" flight period. Significant linear relationships were found between frass weight and each of the following variables: number of egg niches, emerged adult progeny, and gallery length. Mortality in galleries in Douglas-fir and western hemlock logs, respectively, was found to be 9.4 and 12.4% between the egg and larval–pupal stage and 19.5 and 32.1% between the larval–pupal and adult stages.

Most emerging 2nd-instar larvae of spruce budworm, Choristoneura fumiferana (Clem.), tested in the laboratory were photopositive and there was no difference in response between healthy larvae and larvae parasitized by Apanteles fumiferanae Vier. However, in the field, parasitized individuals were under-represented among larvae dispersing on silk threads between tree crowns. There is evidence that this was due to the relatively late emergence of parasitized larvae. These parasitized larvae therefore encountered fewer crawling larvae at the tips of branches, and consequently their propensity for dispersing was reduced.

The vertical distribution of dispersing, parasitized larvae caught on sticky traps more closely resembled that of established larvae than it did the vertical distribution of the overwintering population. This indicates that there was some differential redistribution of parasitized and nonparasitized individuals. Despite these differences, the estimate of parasitism by A. fumiferanae based on mid-crown branch samples is justified because it is most consistent and most closely reflects the overall frequency of parasitism.

Parasitism by Scelio calopteni Riley in eggs of Melanoplus bivittatus (Say) and M. sanguinipes (Fabr.) in Saskatchewan during 1967–1980 was highly aggregated. There was no evidence of any numerical response of the parasites to adult grasshopper density and, furthermore, change in grasshopper population density was independent of percentage parasitism. Thus, it is concluded that parasitism by S. calopteni does not play a significant role in the population dynamics of the two grasshopper species. The relationship between parasitism and wetness in August was highly significant in both grasshopper species and showed that percentage parasitism increased, but at a decreasing rate, up to a certain wetness and levelled off thereafter.

The susceptibility of male and female Pholetesor ornigis (Weed) to the pyrethroid insecticides permethrin, fenvalerate, and deltamethrin, the organophosphorous insecticides azinphosmethyl and phosmet, and the carbamate insecticide methomyl, was compared in the laboratory using two populations from Norfolk County, Ontario. Female P. ornigis were more susceptible than males to permethrin. There was no sexual difference in the susceptibility of P. ornigis to the other five insecticides tested. The implications of these results for the biological control potential of P. ornigis in commercial apple orchards are discussed. The results obtained for permethrin, fenvalerate, azinphosmethyl, and methomyl were compared with those obtained in a study completed 6 years earlier using P. ornigis from another location in Ontario; the results suggest that P. ornigis from Norfolk County have low levels of resistance to permethrin (3.3-fold), fenvalerate (2.2-fold), and methomyl (4.1-fold).

Two species of grasshoppers in the genus Conophyma Zubovskii (Orthoptera: Acrididae) are described as new. Eight male and eight female specimens of Conophyma sharafii n.sp. were collected 8 June 1967 near Altimur Kotal, Paktia Province, Afghanistan, and seven male and four female specimens of Conophyma roberti n.sp. were collected 11 August 1967 near Gardan Deh, Bamian Province, Afghanistan. These discoveries extend the southern range of Conophyma in Afghanistan and bring the total number of described species in the genus to 83.

Two cone-orifice-type traps baited with (Z)-11-hexadecen-1-ol acetate (1.0 mg) and (Z)-9-tetradecen-1-ol acetate (0.05 mg) were placed in each of 5–13 canola (Brassica spp.) fields per year for 7 years at locations distributed throughout the area in Manitoba subject to outbreaks of the bertha armyworm, Mamestra configurata Wlk. (Lepidoptera: Noctuidae). The number of male moths per trap varied from 0 to 821 in the 90 fields trapped. Larval density, in the trap fields and in 185 nearby canola fields, varied from 0 to 105 per square metre. There was a direct relationship between the number of moths per trap and the density of late-instar larvae (L4–L6) for the trap fields and for nearby (within 5 km) fields but variability was loo high to allow accurate prediction of larval densities for individual fields. However, the number of moths per trap could be used to predict the proportion of fields in the vicinity of the trap field that would have larval densities above the economic threshold. No fields with above-threshold larval densities occurred with captures of <20 moths per trap. The proportion of fields with larval densities above the economic threshold increased from 0.10 with 20–30 moths per trap, lo 0.19 with 30–60 moths per trap, 0.64 with 70–100 moths per trap, and 0.91 with over 100 moths per trap. Contamination of catches by non-target species of noctuid moths had insignificant effects on the accuracy of these predictions because even if they were misidentified as M. configurata the number of moths per trap changed only marginally. Populations of M. configurara were higher and local outbreaks occurred more frequently in canola-growing areas adjacent to morainic hills along the Manitoba Escarpment, whereas populations were low in areas of the Manitoba Lowlands and of the Western Uplands. A proposed monitoring system for M. configurata in Manitoba is described.

Comparison of type material and series of Ips cribricollis (Eich.) and I. grandicollis (Eich.) showed that the species are readily separated by external morphology, the pars stridens of the females, and, especially, the genitalia of the males. Earlier work showed that representatives of the two species were not able to interbreed and that their chromosomes were different. These data and the discovery of the two species at the same locality in Central America are compelling reasons for recognition of these entities as separate species.

More than 94% of all spiders captured by Trypoxylon politum (Say) were from three genera: Neoscona, Araneus, and Eustala. The contribution of these spider genera to provisions of T. politum in the eastern and southeastern United States was estimated as follows: Eustala, 17%; Araneus, 21%; and Neoscona, 59%. Provisions in early summer were dominated by Araneus marmoreus Clerck, Eustala sp., and Neoscona hentzii (Keyserling); in mid-summer by N. hentzii; and in late summer by A. marmoreus and Neoscona domiciliorum (Hentz). The proportions of juvenile, subadult, and adult spiders captured depended on the time of year and the developmental stage of the spider. Trypoxylon politum captured male and female subadults, and female adults, but took very few male adults. Trypoxylon politum was found to be stenophagous with respect to prey species and euryphagous with respect to prey size.

Principal components analysis was used to assess niche partitioning between four aphid predators on the basis of oviposition strategies. The study was conducted by sampling abundance and position of the eggs of these predators in corn monocultures in two locations of southern Quebec. The results indicated that the chrysopid Chrysopa occulata Say laid its eggs on corn leaves usually without aphid colonies, and late in the season. All other predators reacted to aphid concentrations. The syrphid Sphaerophoria philanthus (Mg.) oviposited close to the ground, early in the season, and among colonies of the aphid Rhopalosiphum padi (L.). The two coccinellids laid their eggs during July and August with a maximum during tasseling for Coleomegilla maculata lengi (Timberlake) and after pollination for Hippodamia tredecimpunctata tibialis Say. Of these two species, the latter one selected sites at higher levels on the plant, and was more abundant at the edges of the field. It is suggested that the observed niche partitioning cannot be the result of interspecific competition in variable environments such as maize monocultures.

Research into the feasibility of growing peach [Prunus persica (L.) Batsch] in a protected environment structure (PES) was initiated in 1981 by the Ontario Ministry of Agriculture and Food at the Horticultural Research Institute, Vineland Station (Leuty and Miles 1983).

The 0.2-ha PES comprised seven gutter-connected greenhouses, each 5.3 by 58.5 m, with 3.4-m gutter height fibreglass walls and a double polyethylene roof. Temperatures suitable for plant growth were obtained by capturing solar energy beneath the plastic enclosure. Diurnal temperatures ranged between 6 and 27°C. Relative humidity varied between 40 and 95% and remained above 90% within the covered structure for greater than 50% of the time period between bloom (March 20) and roof removal sometime in May.

The symbiosis between bark beetles and microorganisms, mostly fungi, has been investigated and reviewed by Graham (1967) and Whitney (1982). Bark beetles and their habitat fungi have been studied separately but a suitable method for studying them in combined culture is lacking. To study bark beetles in the laboratory, a method for axenic rearing was developed by Bedard (1966), then improved by Whitney and Spanier (1982). Beetle development was retarded or nil without the addition of Brewer's yeast to the diet (H.S. Whitney, Pacific Forest Research Station (PFRC), Victoria, BC, pers. comm.). The inclusion of yeast in the diet precludes studies of symbiosis, such as the role of fungi in beetle nutrition. I describe a method for rearing bark beetles with or without a fungal complement to investigate this symbiosis