Release of the chrysopid, Chrysoperla cornea Stephens, at a rate of ca. 335 000 eggs per hectare, reduced significantly the numbers of apterous adults and nymphs of the green apple aphid, Aphis pomi DeGeer, on dwarf apple trees. Greater reduction in aphid numbers occurred in 1984 than in 1985, and the efficiency of the predator might have been influenced by the predator:prey ratios (1:10 and 1:19) used and by the mean daily temperature that occurred during the test periods. Application of azinphosmethyl (Guthion 50% wp, 0.105 and 0.075 kg AI/100 L) did not adversely affect predation of apterous A. pomi by larvae of C. carnea.

Most of the range of the red turnip beetle, Entomoscelis americana Brown, lies within the Western Cordillera and Interior Plains physiographic regions of North America between latitudes 45°N and 68°N. Entomoscelis americana is associated mainly with three types of vegetation: forests, forest–grasslands, and grasslands. Temperature adaptations in the egg, larval, pupal, and adult stages that permit E. americana to occupy its present range are outlined. Host plant abundance may be the main factor preventing eastward extension of its range. Climate and host plant abundance together appear to limit E. americana to low altitude locations north of 60°N latitude. Eight of the temperature adaptations of the egg and adult stages together seem to limit southward extension of the range. Entomoscelis Chevr. appears to have a Holarctic distribution, with 11 species in the Palearctic region and one (E. americana) in the Nearctic region. The stock giving rise to E. americana may have migrated to North America during the Pleistocene when the Bering land bridge was in existence. Entomoscelis americana likely spent the Wisconsinan glacial period south of the ice in the Western Cordillera and (or) in central United States.

From 1976 to 1986, the average date of first male pheromone trap catch of grape berry moth was 20 May with an average degree-day (DD) accumulation (base 10 °C) of 150.1 (SE = 13.2). Fifty percent cumulative trap catch of the first generation of males averaged 334.1 (SE = 7.8) DD with an average date of 11 June. Degree-day accumulation was a more accurate method for predicting peak male trap catch than predictions based upon vine phenology and calendar date. Within-field distribution and levels of berry moth infestation were markedly affected by the surrounding habitat. Wooded edges or hedgerows were closely associated with an increase in the level of damage along vineyard borders and higher levels of overall infestation when compared with vineyards without wooded edges. Egg and larval infestation levels in wild hosts (Vitis spp.) were greater than those within adjacent commercial vineyards. Early in the season, male berry moth were trapped in high numbers in wooded areas adjacent to vineyards. After mid-July, males were trapped predominantly within vineyards and few were trapped in wooded edges. Movement of adults from wooded areas into vineyards is not suggested by observed patterns of female oviposition. Females oviposited primarily on wild hosts within the wooded areas and within the adjoining vineyard edges throughout the season.

An illustrated key to the genera of Braconinae from America north of Mexico is provided. Lapicida aquatica Quicke gen.nov. and sp.nov. from Ontario and Iowa, and Compsobraconoides robustus Quicke gen.nov. and sp.nov. from Texas, Florida, and Mexico are described and illustrated. Bracon albispina Cameron is transferred to Compsobraconoides and a key is provided to enable its separation from Compsobraconoides rufus Quicke sp.nov. Chartobracon van Achterberg is recorded from the New World for the first time and a new species, C. canadensis Quicke sp.nov. from Canada, is described, illustrated, and distinguished from C. huggerti van Achterberg from Europe. Seliodus Brèthes is synonymized with Bracon Fabricius on the authority of C. van Achterberg. Relationships of the new genera are briefly discussed and notes are provided on all of the Nearctic genera.

A study was conducted to examine the relationship between development rate and constant temperatures (14, 21, 24, 27, 33, 36, 40, and 45°C) for the rangeland grasshoppers Melanoplus sanguinipes (F.) and Aulocara elliotti (Thomas). Non-linear regression was used to generate estimates of lower development thresholds. The chosen model provided for a concave-shaped development rate function at temperatures above the lower threshold and required fewer parameters than previous models. Although experimental results suggested that no precise estimates of upper development thresholds could be obtained, previous field studies indicate that preferred body temperatures may be lower than ambient temperatures and probably are related in part to the thermoregulatory abilities of the two species studied. Results will be of interest to insect ecologists and those studying grasshopper biology as well as researchers and pest managers interested in predicting grasshopper development.

A phenology model for jack pine budworm, Choristoneura pinus pinus Freeman, is presented. Linear and nonlinear relationships between temperature and the development of overwintering larvae, instars 2–7, and pupae are determined, as is variation in the development of each instar. The model uses as input daily maximum and minimum temperatures corrected for the effects of bark and bud microclimate and simulates the number of insects in each instar on a given calendar date. Variation in development of all stages is included. Simulations matched observed data well for north-central and northwestern Ontario in 1986, but overestimated time of development for northwestern Ontario in 1987. Simulations under low, medium, and high temperature conditions revealed that a nonlinear equation for rate of development was necessary for simulating emergence whereas linear rate equations were adequate for simulating development of the feeding instars. The combined effect of bud and bark microclimate on model performance was equal to that which resulted from the use of nonlinear developmental equations.

The saltatorial orthopteroid insects did not originate in North America. Five avenues of entry were utilized in migration from other parts of the world. These were: (1) ancestral forms migrated to this region in Pangaean times when all continents formed a single land mass; (2) later in time, taxa migrated from Europe when Eurasia and North America were still joined, or later via an Atlantic land bridge; (3) ancestral forms migrated northward from the Neotropical region before the separation of the two continents or, much later, when the two continents became rejoined; (4) later arriving taxa entered North America during the Pleistocene via a Beringian land bridge; (5) some species are very recent immigrants, either because of the activities of man or by migration into Canadian territory from the south.

The fossil record is very incomplete. It indicates past climatic conditions, but is of limited assistance concerning extant taxa.

Pleistocene glaciation had a profound effect upon the distribution of extant species. Many species were forced to move southward to escape the advancing ice. Some species probably were eliminated. It is clear that most of the extant species have migrated northward since the recession of the Wisconsin glacier.