Antifeedants for controlling larval feeding of several Neodiprion sawflies were evaluated in laboratory and field studies. Nine commercially available insect antifeedants and a hexane extract of the juvenile foliage of jack pine, Pinus banksiana Lambert, were tested on larvae of six species. In laboratory bioassays larvae exhibited varying sensitivity to antifeedants; generally species with monophagous or restricted oligophagous feeding habits were most sensitive. In the laboratory the Swaine jack pine sawfly, Neodiprion swainei Middleton, had severely restricted feeding, development, survival, and fecundity. Triphenyltin hydroxide was toxic to N. swainei and to European pine sawfly, N. sertifer (Geoffroy). In field tests certain antifeedants disrupted N. swainei feeding and development. The colonial behavior of larvae often was disrupted and solitary larvae fell from trees or wandered on twigs. Colony disruption by most antifeedants was temporary and many larvae resumed feeding.

Brachypogon canadensis n. sp. is described from western Quebec; the known range of the species extends southwards to Florida. It is perhaps most nearly allied to the widespread Palaearctic species B. vitiosus (Winnertz).

Tests of a synthetic insect growth regulator (Altosid SR-10, or Methoprene, Zoecon Corp., Palo Alto, Calif.) have been completed recently at Chalk River Nuclear Laboratories. This paper reports on the effectiveness of this promising material in tests on several species of mosquitoes of this area. The low toxicity to mammals, the relative absence of deleterious effects on non-target aquatic organisms under normal use (Staal 1975), the fact that Altosid is readily biodegradable and is effective at low rates of application would recommend this material for the control of mosquito larvae. Reports in the literature on the use of juvenile hormone-type compounds have dealt mainly with mosquitoes in the southern United States; for example, Schaefer and Wilder (1973) reported on Aedes nigromaculis, A. melanimon, and Culex tarsalis in California. In our tests, we wished to determine its effectiveness on local species and in mosquito breeding pools where temperatures would be lower than in the work mentioned above.

The 50 known species of North American Clubiona Latreille, 1804 are rearranged in seven species-groups as follows: trivialis group (1 Holarctic, 4 Nearctic), obesa group (11 Nearctic), reclusa group (2 Holarctic, 3 Nearctic), pallidula group (1 Holarctic), abboti group (25 Nearctic), lutescens group (1 Holarctic, 1 Nearctic), maritima group (1 Nearctic). Clubiona quebecana and C. angulata are described as new species from eastern North America. C. kuratai Roddy, 1966, originally described from the female only, is synonymized under C. chippewa Gertsch, 1941, which was originally described from the male only. C. opeongo Edwards, 1958 and C. bishopi Edwards, 1958 are redescribed, the male of the former and the female of the latter not having been previously described.

The effects of temperature on rates of oviposition and development of immature stages of Pissodes strobi from Sitka and white spruce were investigated in the laboratory. Maximum rate of oviposition occurred at 20° to 26 °C. Brood development from egg to emergence took 888 and 785 degree-days above a threshold of 7.2 °C for the weevil from Sitka and white spruce, respectively.

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.

The feeding habits of Melanoplus bivittatus (Say) and M. femurrubrum (DeGeer) in an Ontario grassland were investigated by analyzing crop contents. The study revealed that both species are mixed feeders which prefer forbs over grasses. Both species ingested a wide range of host plants in the field, showing preferences for some species over others. Differential growth and mortality resulted when grasshoppers were reared on different host plants.

The life history and the immature stages, especially the ultimate larval instar, of Enargia decolor (Walker), are described and illustrated. This insect has only one generation a year in northern Alberta. It overwinters in the egg stage. The first two larval instars roll leaves and feed on the mesophyll. The last four larval instars feed on the edge of the leaves, and construct flat cases by webbing two leaves together. Pupation occurs in the soil during July. Adults emerge from late July until late August; the eggs are laid in August. Fifteen species of parasites and one species of hyperparasite were reared from larvae of E. decolor. Five of the parasites are known to have issued from other lepidopterous species feeding on aspen.

A natural virus epizootic, caused by a nuclear polyhedrosis virus, was observed in several populations of the European skipper, Thymelicus lineola (Ochs .), at Normandin, Que., in 1974 (Smirnoff 1974). A substantial supply of this virus was collected and experiments were conducted under laboratory and field conditions to evaluate its pathogenicity against the skipper, its possible transmission from one generation to the next, and its potential as a means of control of T. lineola, a serious insect pest of forage crops in several regions of Quebec (McNeil et al. 1975).

A frequently used method for determining the threshold temperature for insect development is based on the expression for the hyperbola and its reciprocal (Bean 1961). This method has certain disadvantages, the major one being that the developmental velocity curve is sigmoid and the selection of a linear portion of this curve has a subjective element (Morris and Fulton 1970).

First-stage forest tent caterpillar larvae were tested for the presence of active and sluggish behavior types such as Wellington found in Malacosoma californicum pluviale (Dyar). Larvae capable of directed movement towards a 30 w light source were classified as active. Larvae were tested on 3 consecutive days, and only a small percentage responded on all 3 days. A much larger percentage remained sluggish throughout the period. Chi-square tests confirmed that the differences in response were not random. There was a tendency for some larvae to respond to light during the test and for others not to respond. The reduced consistency in the response of "active" larvae in M. disstria Hübner compared with that reported for M.c. pluviale may be partly due to real behavioral differences, but it also may be partly due to some procedural differences between our tests and Wellington’s.

The males of four very similar species of Macrocera are keyed and briefly described. They are grandis Lundström (Finland, U.S.S.R.), nobilis Johnson (Nearctic, widespread), summatis n. sp. (Sweden), insignis n. sp. (New Hampshire). The group of species is characterized as the nobilis group.

The mycetophilid Macrocera nobilis Johnson, previously known only from forests in New Hampshire and Massachusetts, is here reported from caves in Oklahoma, Missouri, Kentucky, Tennessee, and West Virginia. A study of populations in Oklahoma shows that the short-lived adults mate in cave entrances, but that oviposition, larval development, and pupation occur only in the dark zone of caves. The larvae build extensive webs upon which they travel and which they use to capture insect prey (mostly other Diptera). Reproduction and life cycle development is not seasonal. The larval stage lasts 9 or 10 months, and the pupal stage about 2 weeks.

The genus Ismarus Haliday of the New World is revised. Twenty-one species are recognized, described, and keyed, of which the following 16 are new: I. brevicornis n. sp. ♂ (Mexico), I. clarkae n. sp. ♀ (Canada), I. dux n. sp. ♂ (Panama, Costa Rica), I. flavicrus n. sp. ♀ (Mexico), I. flavigena n. sp. ♂ (Canada, U.S.A.), I. gibsoni n. sp. ♀ (Canada, U.S.A.), I. gracilis n. sp. ♀ ♂ (Mexico, Panama), I. helavai n. sp. ♀ (Panama), I. masoni n. sp. ♀ ♂ (Mexico), I. mexicanus n. sp. ♀ ♂ (Mexico), I. neotropicus n. sp. ♀ ♂ (Brazil), I. porteri n. sp. ♂ (Argentina), I. orion n. sp. ♀ (Mexico), I. rex n. sp. ♀ ♂ (Mexico), I. varicornis n. sp. ♀ (Brazil), and I. vigil n. sp. ♂ (U.S.A.). The hitherto unknown males of I. americanus Fouts and I. nevadensis Kieff. are described. I. rugulosus Foerst., I. halidayi Foerst., and I. flavicornis (Thorns.), previously known from Europe, are recorded from Canada and the U.S.A. Higher classification, interrelationships, and world distribution of Ismarus are discussed.

Females of Eupteromalus dubius (Ashm.) oviposit on pupae of cyclorrhaphous Diptera and the larvae develop gregariously as ectoparasites. Details of the life history of E. dubius are described. A progressively lower percentage of female progeny of E. dubius matures as the parasite:host ratio increases. Three mechanisms that may cause this sex ratio change are examined and discussed.

Euxoa vernalis, allied to Euxoa olivia (Morrison) and Euxoa septentrionalis (Walker), is described from south-western United States and from Mexico. Adults and genitalia of the three species are illustrated.

The sex pheromones of Archips argyrospilus (Walker) and Archips rosanus (L.) were field evaluated to determine if they could be used to monitor populations in orchards where pest management programs were applied. Traps baited with the sex pheromones of A. argyrospilus caught males which reflected population levels estimated by other sample methods. Traps baited with the sex pheromones of A. rosanus caught high numbers of males but the numbers did not correlate with other population estimates. A. rosanus has a wide host range, and trap data indicate that males were attracted from sources outside the monitored orchards. Results indicated that the sex pheromones of A. argyrospilus could be used to estimate populations but with A. rosanus further studies on trap placement are necessary to minimize male influx.

A reinvestigation of the sex pheromone of the eastern spruce bud worm, Choristoneura fumiferana (Clem.), showed that it contains 11-tetradecenal in the ratio 96% trans-: 4% cis-. Field trapping showed the pure trans- compound to be only slightly attractive. Maximum attraction occurred in the range 2% to 5% cis-.

Parasitism in natural populations of Hyphantria cunea Drury was measured in New Brunswick and Nova Scotia, 1957–1973. Thirteen parasite species were recovered during this period but only a few caused an appreciable degree of mortality. The per cent mortality showed an immediate rather than a delayed response to host density, the relationship being direct up to a density of about 10 host colonies per mile, then inverse. Possible reasons for this sort of relationship are discussed.

Parthenogenesis in North American mayflies occurs in Ameletus ludens Needham (Clemens 1922), Ephoron album (Say) (Britt 1962), Stenonema fermoratum (Say) (McCafferty and Huff 1974), S. interpunctatum (Say), S. pulchellum (Walsh), and S. vicarium (Walker) (Huff and McCafferty 1974). Attempts to determine its occurrence in the genus Hexagenia are reported for H. limbata occulta Walker (Neave 1932), H. limbata (Serville) (Hunt 1953), and H. bilineata (Say) (Thomforde and Fremling 1968). The purpose of this note is to report hatching in unfertilized eggs of H. rigida McDunnough.