The genus Megasoma Kirby as it occurs in North and Central America is discussed, and the taxonomic history of this group in this area is reviewed. A key is presented to aid in the separation of the 10 forms currently known from these areas, as well as one species that may be taken in the future. Each species is illustrated and discussed. Three new species, Megasoma sleeperi from Southern California, Megasoma cedrosa from Central Baja California, and Megasoma lecontei from Southern Baja California, are described.

A new oribatid mite (Acari), Camisia abdosensillasp.nov., is described from all instars, based on specimens from British Columbia, Canada. This species occurs on branches and foliose lichens in the canopies of western hemlock, Tsuga heterophylla (Raf.) Sarg., 1898 (Pinaceae), and Pacific silver fir, Abies amabilis (Dougl. ex Loud.) Dougl. ex J. Forbes, 1939 (Pinaceae), growing in high elevation coastal forests. The most unusual feature of this species is the distinctive structure of the prodorsal trichobothrium in adults; the significantly reduced sensillus is completely enclosed within the bothridium. A resemblance between the structure of this organ and those of the superfamily Crotonioidea appears to have resulted from parallel evolution rather than being evidence of a sister-group relationship. Another species, Camisia islandica Gjelstrup and Solhøy, 1994, is herein recognized as a junior synonym of Camisia solhoeyi Colloff, 1993. A key of the Nearctic species of the genus Camisia is given.

The genus Cricotopus of the arctic zone of the Nearctic region, represented by 14 species in seven species groups, is reviewed. Descriptive notes on 11 species supplement those given by Hirvenoja (1973), with addition of descriptions of immature stages of C. lestralis (Edwards) and larva of C. tristis Hirvenoja. Two new species names, C. beringensis and C. trilobus, are proposed. New species names synonymies are Chironomus basalis Staeger and Chironomus holmgreni Kieffer with Chironomus tibialis (Meigen) (= C. tibialis). Several undetermined individuals are assigned to the fuscus group. Eleven species are Holarctic in distribution, of which C. bicinctus (Meigen) and C. sylvestris (Fabricius) are circumboreal. Seven species are restricted to the arctic zone, two are wide-ranging in both arctic and temperate zones, and four temperate species barely extend into the arctic zone. Keys to all known life-history stages and some ecological data, primarily of larvae, are given.

Black; head and face rufous ; palpi grayish white; antennæ. yellowish gray, annulate with black, tips, white; wings black, with a costal and dorsal white spot opposite each other just before the middle (sometimes united, forming a fascia), a white fascia (sometimes interrupted) beyond the middle, a costal white spot in the apacial portion of the wing, and near the apex an obliquely curved costal white streak; apacial portion of the wing bronzy, iridescent, ciliae grayish brown;

Laboratory assays and field surveys showed that Ascosphaera larvis (Bissett) is a pathogen of alfalfa leafcutting bee larvae, capable of causing high mortality in commercial populations. In one population, over 21% of bees were found to be infected by A. larvis. However, overall levels of the disease are low and it is unlikely that this pathogen poses an immediate threat to commercial leafcutting bee populations in Canada. The LD50 was determined to be 1.9 × 105 spores/bee. Elevated levels of CO2 are required for in vitro spore germination. The disease can easily be diagnosed within bee cells by X-ray radiography, thereby enabling disease levels to be monitored using conventional methods utilized by the industry to monitor leafcutting bee quality.

The plum curculio, Conotrachelus nenuphar (Herbst), is a serious pest of stone and pome fruits (Rosaceae) in eastern North America. We recorded captures of adult plum curculios in the field and measured electroantennogram (EAG) activity in the laboratory associated with cultivars of four hosts, ‘Formosa’ Japanese plum (Prunus salicina Lindl.), ‘Stanley’ European plum (P. domestica L.), ‘Empire’ apple (Malus domestica Borkh.), and ‘Loring’ peach (P. persica (L.) Batsch) (Rosaceae) to determine whether hosts that may be attractive to the plum curculio under field conditions also elicit positive EAG responses. Trap captures of adults on ‘Formosa’ plum were significantly greater than on any other host, and corresponding headspace extracts also produced strong EAG responses throughout the active season. ‘Stanley’ plum and ‘Loring’ peach, the other stone-fruit hosts included in the study, elicited strong EAG responses throughout the season, although trap captures associated with these hosts were generally not as high as for ‘Formosa’ plum. Throughout the season, trap captures of adults were significantly lower for ‘Empire’ apple than for ‘Formosa’ plum, and EAG responses were much lower than for all stone-fruit hosts. Our results indicate that volatiles from ‘Formosa’ plum likely contain uniquecompounds or are comprised of ratios of stimulating compounds that make it much more attractive to plum curculio in the field.

A new host record for the sawfly Monostegia abdominalis (F.) was obtained in Quebec. The host plant, terrestrial loosestrife (Lysimachia terrestris (L.) BSP), was abundant on a lake shore due to regular flooding, enabling the sawfly to reach a high population level. Two generations occurred each year. The immature stages and aspects of their behaviour, and female oviposition behaviour, are described.

New Brunswick experienced its first recorded outbreak of hemlock looper, Lambdina fiscellaria fiscellaria (Guenée) (Lepidoptera: Geometridae), in 1989 (Magasi1990). Since 1993, populations have remained at endemic levels. From 1989 to 1994, when annual egg surveys were conducted (from October to April) on balsam fir, Abies balsamea (Linnaeus) Miller (Pinaceae) to forecast the next years' population for planning foliage protection programs, the egg parasitoids Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae) (Hartling et al. 1991) and Telenomus near alsophilae Viereck (Hymenoptera: Scelionidae) were frequently reared from overwintering looper eggs. We believe two factors can cause an underestimation of egg parasitism rates by Telenomus near alsophilae: (i) eggs parasitized by Telenomus near alsophilae can be difficult to identify, and need to be reared to detect the black shading on the chorion which ranges from a mere dark spot to some gradation of black over the entire surface; and (ii) additional parasitism by this parasitoid might occur in spring. Our estimates of egg parasitism rates were as high as 23% (n = 93) from spring-collected looper eggs incorrectly classified as viable until incubated in the laboratory. We describe part of an experiment that confirms spring parasitism by this species, and illustrate the implications to operational looper control operations.

A 3-year study in two orange orchards in Egypt showed that when sprays were eliminated, citrus brown mite, Eutetranychus orientalis (Klein), was not a problem. The response of both phytophagous and predaceous mites to cessation of pesticide sprays was determined.

The apple maggot, Rhagoletis pomonella (Walsh), is a major pest of apples in Nova Scotia, and has in recent years become a serious threat to integrated insect control. This paper is an account of its past history, economic importance, seasonal history, natural enemies, the present cultural and chemical control practices, and the prospect of using alternative control measures.

The North American species of Dicladocerus are revised. Twelve new species from North America and one from Japan are described and illustrated: alaskensis, australis, prealatus, occidentalis, exoteliae, epinotiae, betulae, vulgaris, nearcticus, pacificus, japonicus, and terraenovae. The species attacking larch casebearer are nearcticus, pacificus, terraenovae, all Nearctic, and japonicus and westwoodii, Palaearctic. Relationships of species-groups in North America are discussed. A key to species, and host records are included.

For many years the true members of the illibalis group (usually placed in the wastebasket genus Pyrausta) have been listed as two or three species, under the names gracilalis Hulst, illibalis Hübner, and arsalteulis Walker. I was considerably surprised, therefore, to find several additional species standing, for the most part unrecognized, in North American collections. A further species, haedulalis Hulst, was compared by its author to gracilalis, and was placed by McDunnough (1939) between gracilalis and illibalis; I have seen the badly damaged tvpe of haedulalis in the collection of Rutgers University, and am convinced ihat the species does not belong in the present group.

Cuticular damage of Spodoptera exigua (Hübner) pupae, caused by puncturing with a sterilized insect pin, resulted in enhanced susceptibility to the entomopathogenic nematode Steinernema carpocapsae (Weiser), but cold shock (5 °C for 24 h) did not alter susceptibility. The additional avenue of entry for the nematode probably accounted for the increased mortality of the damaged pupae. In all treatments, some dead pupae contained Xenorhabdus nematophilus (Poinar and Thomas), the symbiotic bacterium of S. carpocapsae, but no nematodes. More nematode-killed pupae containing X. nematophilus but no nematodes were found in the cold-shock treatment than in the room-temperature control (62.6 versus 46.9%). In contrast, fewer nematode-killed pupae containing X. nematophilus but no nematodes were found in the damaged pupae compared with the undamaged control (25.0 versus 45.1%). Moreover, mortality of nematodes within the cadavers of cold-shocked insects was higher than in the cadavers of non-cold-shocked insects. These results suggest that the stressors, cold shock and cuticular damage, produce fundamentally different responses in insects exposed to them, and that the physiological state of the insect greatly influences nematode survival in the host and hence nematode recycling in the environment.

This paper reviews the taxonomic relationships among taxa within the superfamily with particular reference to previous discussions of Craspedolepta Enderlein, 1921. The genus is considered to belong within the tribe Aphalarini Löw. The paper also identifies the Nearctic species which should be included within the genus Craspedolepta.

The nine species of the endemic North American Agabus seriatus-group are revised. All species occur west of the Rocky Mountains with A. lugens LeConte also occurring on the Great Plains and A. seriatus (Say) transcontinental in mid-latitudes. The species are placed in four subgroups, namely the seriates-subgroup with A. seriatus, A. lugens, and A. perplexus Sharp; the brevicollis-subgroup with A. brevicollis LeConte, A. pandurus Leech, and A. roguus new species; the ilybiiformis-subgroup with the single species A. ilybiiformis Zimmermann; and the regularis-subgroup with A. regularis LeConte and A. minnesotensis Wallis. Geographical variation in A. seriatus is analyzed and it is concluded that recognition of subspecies of A. seriatus is not warranted and A. s. intersectus (Crotch), NEW SYNONYMY, is relegated to a synonym of A. seriatus. For each species the following is provided: synonymy; description and illustration of taxonomically useful characters; notes on relationships, variation, distribution, and ecology; and a map of collection localities. A key to species is provided and lectotypes designated for A. brevicollis LeConte, A. lugens LeConte, A. perplexus Sharp, Gaurodytes suturalis Crotch (= A. lugens), and Ilybius regularis LeConte.

Male size is an important parameter in mate choice for many species and has been associated with such female life-history parameters as increased fecundity or fertility and larger progeny (Phelan and Baker 1986; Savalli and Fox 1998, 1999; Brown 1999). In the alfalfa blotch leafminer, Agromyza frontella (Rondani), intraspecific larval competition may significantly influence the size of both males and females (Quiring and McNeil 1984a). The influence of female size on female reproductive success has been studied (Quiring and McNeil 1984b, 1984c), but to date, no attention has been given to the possible effects of male size. The objectives of this study were to determine if differences in male size, the result of intraspecific larval competition, affected male longevity and reproductive success, as well as various parameters of female reproduction.

Among the parasites so far found to attack and destroy Aletia argillacea Hübn., aside from two not reared to the perfect state, are the following: Obtained from the egg, Trichogramma pretisa n. sp. from the larva, Tachina aletiæ n. sp., and Sarcophaga sarraceniæ Riley ; from the pupa, Pimpla conquisitor (Say), Cryptus nuncius Say, Chalcis ovata Say and, Cirrospilus esurus, n. sp.

The egg, first larval instar, last larval instar, and pupa of Sialis cornuta Ross are described and illustrated.