The taxonomy, distribution, and ecology of the Holarctic species of Agabus (Coleoptera: Dytiscidae) are reviewed. Seventeen species occur in both the Nearctic and Palaearctic regions. The following new synonymy is proposed (valid name given last): A. solus Leech = A. adpressus Aubé; A. sharpi Jacobson and A. pseudoconfertus Wallis = A. opacus Aubé; A. kenaiensis Fall = A. wasastjernae (Sahlberg) and A. hudsonicus Leech = A. zaitzewi Poppius, thus each of these species is recognized for the first time as being Holarctic. The Nearctic species A. ontarionis Fall is reduced in status to a subspecies of A. fuscipennis (Payk.). Agabus congener (Thunb.) is redefined and Nearctic specimens formerly placed in the species are assigned to A. thomsoni (J. Sahlberg). The reports of Palaearctic occurrence of A. approximates Fall and A. discolor (Harris) are considered to be in error, the records referring to A. levanderi Hellén.

Sticky traps are commonly used for monitoring insects in studies of their ecology (Southwood 1966) and in programs to manage their numbers (Flint and van den Bosch 1981). These traps may intercept flying insects or may visually attract insects over a distance (Southwood 1966). The relative sensitivity of an insect eye to different wavelengths of light may differ among species (Wigglesworth 1972) and therefore color can affect the quality and magnitude of trap catches (Prokopy and Owens 1983; Southwood 1966). The effect of color on trap catches therefore is often the first step in evaluating trapping methods for use in monitoring insects. Insects attracted to and landing on colored traps are retained by paint- or spray-on adhesives that have been developed specifically for this purpose. This paper reports on the effect that one of these adhesives has on the spectral reflectance of colored traps.

The genus Zacremnops Sharkey & Wharton is erected to include 2 New World species formerly placed in Megagathis Kriechbaumer. Phylogenetic relationships between Zacremnops and selected genera of Agathidinae are briefly discussed.

A key is given for 4 subgenera in the aphid genus Uroleucon Mordvilko in America north of Mexico. An annotated list and keys are presented for 44 species of the subgenus Uroleucon, 12 species of the subgenus Uromelan Mordvilko, and 1 species of the subgenus Satula Olive. Nine new species are described in the subgenus Uroleucon: Uroleucon (Uroleucon) alaskense n. sp., U.(U.) arnesense n. sp., U.(U.) boreale n. sp., U.(U.) chani n. sp., U.(U.) deltense n. sp., U.(U.) elephantopicola n. sp., U.(U.) ivae n. sp., U.(U.) maximilianicola n. sp., and U.(U.) vancouverense n. sp. Two subspecies, U. (Uromelan) illini subspecies crudae and sangamonense, are listed here merely as color forms of illini (Hottes and Frison), not subspecies. Uroleucon (Uroleucon) muralis Buckton, U. (Uromelan) compositae (Theobald), and U.(U.) solidaginis (Fabricius) have been listed as present in North America, but there appear to be no authentic records of their occurrence. Uroleucon (Uroleucon) pseudochrysanthemi (Olive) is declared to be a synonym of U.(U.) lanceolatum Patch, and U. (Uromelan) squarrosum (Sanborn) as a nomen dubium.

A search is being conducted to determine the indigenous parasites and predators of the alfalfa weevil, Hypera postica (Gyll.), in Alberta (Schaber 1981). A clearer understanding of the biology of the predator Odynerus dilectus Saussure will augment control of the alfalfa weevil in an integrated pest management program.

Odynerus dilectus has been recorded in the United States (Bohart et al. 1982) and in Alberta, Canada (Strickland 1947). In California, Linsley and Michener (1942) reported that females stocked their nests with small caterpillars, but Bohart et al. (1982) reported that in Utah females of O. dilectus provisioned their nests with larvae of the alfalfa weevil. This paper summarizes data about the nesting and prey-provisioning behavior of O. dilectus in southern Alberta.

The existence of a diurnal cycle in the rate of production of acoustic signals by aquatic heteropterans has been observed by several workers (Leston 1955; Mitis 1936; Schaller 1951; Theiss 1983). These accounts all mention an increase in acoustic activity in early evening. Jansson (1968, 1973) determined that the single strongest component releasing acoustic behavior was light level in the genera Cenocorixa and Callicorixa and that different species of Cenocorixa had different maxima. The study reported here began as an examination of diel periodicity of song incidence in the corixid bug Palmacorixa buenoi but results were substantially different in kind from most other studies of this nature in the literature.

Females of the polyphagous ichneumonid parasitoid, Exeristes roborator (F.), that were conditioned for 10 days to hosts in a specific habitat demonstrated associative learning by responding with ovipositor probes into the habitat alone. Females conditioned immediately after eclosion showed a higher participation rate, intensity, and duration (approximately 7 days) of learned behavior than those conditioned 5 or 10 days after eclosion, despite the fact that newly eclosed females did not probe for hosts with their ovipositors until 4 or 5 days after eclosion. The reduction in the learning ability of females within a short time after eclosion may impart a selective advantage to E. roborator by reducing the costs of learning. It could also reflect developmental constraints on the process of learning. The results suggest that carefully controlled associative learning could be exploited to improve the efficiency of host location by parasitoids released in biological-control programs.

The economics of entomological effort is discussed from the viewpoint of the pesticide industry in Canada. Industry is concerned primarily with obtaining an acceptable return on investment. To illustrate the investment trend in insecticide development in Canada, the cost of research and development (R&D) from discovery to registration is examined. Statistics on retail sales of pest-control products, on new compounds being tested, and on the number of new registrations indicate declining interest in insecticide development in Canada. The present and future role of the Canadian pesticide industry in insecticide development is discussed.

Melanoplus sanguinipes (F.) is one of several species of grasshoppers that periodically causes severe economic damage to cultivated crops and rangeland plants in western Canada and the USA. The usual method of controlling outbreaks of these pests has been the application of broad-spectrum chemical insecticides, such as malathion, an organophosphate, and sevin, a carbamate (Blickenstaff et al. 1974; Onsager 1978). These insecticides can cause undesirable environmental side effects.

The fundatrix morph of Longicaudus trirhodus (Walker) is described for the first time. The main difference from the apterous viviparous female is the absence of cornicles. Fundatrices as well as both apterous and alate viviparous female were collected on cultivated roses in May and early June, 1984 at Fredericton, NB.

Mathematical discussions of models of functional response (predation rate as a function of prey density) have usually emphasized description of the shape of the functional-response curve. However, lack of congruence between experimental design and data analysis and under-utilization of appropriate statistical methods of analysis have hindered an empirical synthetic treatment of such feeding behavior. Here we review existing experimental and statistical procedures with reference to Holling's generalized model of functional response, and describe: (1) an experimental design compatible with the assumptions of the model; (2) a maximum-likelihood method for fitting the model; (3) several methods for statistical comparison of sets of functional-response curves; and (4) an exploratory graphical method for examining patterns of variation among larger numbers of samples.

Chow and Mackauer (1984) recently reported on inter- and intraspecific larval competition between Aphidius smithi Sharma & Subba Rao and Praon pequodorum Viereck (Hymenoptera: Aphidiidae), when both were parasitizing the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae). In interspecific competition, a 1st-instar Praon larva usually eliminated, by physical combat, an Aphidius larva that was up to 48 h older. However, circumstantial evidence suggested that once an Aphidius larva had reached an advanced stage of the final (4th) instar, it was able to complete development and pupate, even in the presence of a younger Praon competitor.

Parasitization of larch casebearer, Coleophora laricella (Hübner), by the internal larval parasite, Agathis pumila (Ratz.), commonly has been found to decrease between successive samples in the spring. The decrease has been attributed in part to mortality of A. pumila, which prolongs the casebearer's larval stage, thereby exposing it to subsequent parasitism by other species that are intrinsically superior (Smith 1929) and to secondary parasitism of A. pumila (Graham 1949; Quednau 1970; Raske and Schooley 1979; Ismail and Long 1982). Another reason may exist for this decrease in parasitization by A. pumila: A higher percentage of parasitized than unparasitized larvae may descend from the larch foliage to the understory vegetation, which is not in the normally sampled universe (Webb 1953; Moody 1977; Denton 1979; Long and Theroux 1979; Ryan 1983). Eidmann (1965) reports that casebearers are often found on the undergrowth when high populations strip the trees, but prior to this no one had reported any connection with parasitism. This movement may result in a decreased percentage of parasitized larvae remaining on the larch foliage. Evidence presented here substantiates this hypothesis for one location, but for a more general conclusion other areas should also be examined.

In Canada, 78 of the most important weed species are introductions from Eurasia (Frankton and Mulligan 1970). Classical biological control aims to reduce the density of alien weeds below the economic threshold through introduction of specific herbivores from the native distribution area (Peschken 1979). During extended field surveys in central and southeastern Europe, the Commonwealth Institute of Biological Control established the root-mining tortricid Agapeta zoegana Haw. as a promising control agent for Centaurea diffusa Lam. and C. maculosa Lam., 2 important ranch weeds in southwestern Canada (Harris and Myers 1984) and the northwestern United States (Maddox 1982). Due to the limited host range and suitable climatic conditions this moth was chosen for introduction into North America (Müller et al. 1982; Müller 1984). We wish to report an attractant that may be used to monitor the establishment of this beneficial species in its new habitat.

Pupae and 3rd-instar larvae of Pseudaletia unipuncta (Haw.) survived longer at 0 and −2°C than other immature stages, and insects reared at 15°C were more cold tolerant than those reared at 20°C. Egg survival at 0°C varied greatly among replicates suggesting genetic differences among females. No adults survived 2 weeks at 0°C. Peridroma saucia (Hub.) would not rear satisfactorily at 15°C and, other than eggs, all stages tested were from rearings at 20°C. Eggs from adults at 15°C were more cold tolerant than those from adults at 20°C. There were no differences in survival among any of the larval stages or pupae. Some adults survived 6 weeks at 0°C. No stage of either species survived over 8 weeks at 0°C nor 4 weeks at −2°C indicating that overwintering on the Canadian prairies is unlikely.

In opening the symposium, I referred to 3 reasons why I felt the symposium was so important and why I was pleased to participate in it. The first of these reasons was our need to define the benefits of entomology in economic terms so that we could make our case for funding. This point was made repeatedly. Those allocating resources see many outstretched hands. The public demands return on investments. If we are to be successful in having funds allotted to entomology, we must justify these in terms of real return to society.

The influence of potato cultivar (Solanum tuberosum tuberosum (L.) cvs. Katahdin (long-season), Norchip (mid-season), and Superior (short-season)) and vertical leaf position on certain life statistics of the green peach aphid, Myzus persicae (Sulzer), were assessed in a glasshouse environment. Aphids were caged on upper and lower leaves of each cultivar. Developmental time requirements for pre-reproductive life stages were similar among cultivars and between leaf positions. Longevity was similar among cultivars within leaf position. However, aphids survived 62.3, 53.6, and longer on lower leaves than on upper leaves of Superior, Norchip, and Katahdin (p < 0.05 on Superior and Katahdin). Mean generation time (MGT) was similar among cultivars on upper leaves. On lower leaves, MGT was shorter on Superior than on Katahdin. MGT was 15.2, 6.9, and shorter on lower leaves than on upper leaves of Superior, Norchip, and Katahdin, respectively (p < 0.05 on Superior). Total fecundity and intrinsic rate of increase were greater on the lower leaves of each cultivar.

The deodar weevil, Pissodes nemorensis Germar, is a vector and wounding agent associated with pitch canker fungus, Fusarium moniliforme Sheld. var. subglutinans Wr. & Reink., in the southeastern United States (Blakeslee et al. 1981). This univoltine weevil breeds in southern pines that have been stressed by factors such as fire, lightning, or mechanical injury (Baker 1972). The adults feed on phloem after chewing through the outer bark. Females deposit eggs in some of these feeding pits and then plug the hole with macerated phloem (Atkinson 1979). Larvae tunnel under the bark and feed on phloem as they develop.

The northern subarctic region is the limit of the distribution of Drosophilidae (Toda 1984); the family is of tropical origin (Throckmorton 1975). Hence, a drosophilid community inhabiting the northernmost subarctic region is likely to have a relatively simple community structure. This note presents information on the habitat preferences of a drosophilid community at Inuvik (68°22′ N, 133°45′ W) in the Mackenzie delta, Northwest Territories, Canada.

The Holling disc equation (Type-II functional response) for predation, which is mathematically equivalent to the Michaelis–Menten enzyme-kinetics and to the Monod microbial-growth equations, has been used in several linear transformations for parameter estimation. The most commonly used is the Lineweaver–Burk double reciprocal. We compare 4 linearizations of the disc equation and a direct nonlinear fit to stimulated predation data. We conclude that (1) the best parameter estimates are obtained by the direct nonlinear method and (2) the Lineweaver–Burk is the worst of the (all unsatisfactory) linearizations. We propose a new nonparametric technique to use when nonlinear methods cannot be used.