Hemolymph proteins of the Douglas-fir cone moth, Barbara colfaxiana (Kft.), in the year of pupation (year P) and the next year (year P + 1) were studied by visual examination and analysis of digitized images of isoelectric focussing patterns. Differences in these proteins between light and dark individuals in year P and P + 1 were not related to dormancy duration but reflected the extent of pharate-adult development. Hormone applications were more effective in changing hemolymph proteins of light insects than those of dark ones. Changes in the hemolymph proteins of light insects in year P + 1 were not very obvious by visual examination of gels but were readily detectable by digital image analysis and showed that development occurred in these insects through June-September leading to visible pigmentation differences observable in relation to dormancy commitments of these insects.

It was hypothesized that Delia antiqua (Meigen), the onion fly, would show high preference in the field for trap colors reflecting visible wavelengths between 400 and 480 nm at reflective intensities above 37%. This preferred spectral zone (PSZ) was tested in an onion field in 1984, using cardboard traps painted with 11 blue, violet, and green hues, and two PSZ reflecting colors of varying intensity. It was found that colors with peak reflective wavelengths occurring between 400 and 470 nm, at or above 30% reflectance intensity, were most preferred. Wavelength-specific reflectance intensity was shown for the first time under field conditions to influence the magnitude of color preference in the onion fly.

Larval color morph frequencies were observed in the offspring of hybrid and backcross matings between pure Choristoneura occidentalis Freeman and C. retiniana (Walsingham) laboratory lines. Offspring of hybrid matings were mostly brown larval forms but intermediate and green larvae also occurred. Progeny of backcrosses to C. occidentalis were almost entirely brown larvae. Backcrosses to C. retiniana yielded mostly green larvae but a substantial number of intermediate and brown larvae also were in the progeny. There was no evidence that larval color is sex-linked or sex-limited.

The proportion of large Camponotus modoc workers returning to the nest with solid food was significantly less than that of smaller workers. The average weight of ants collected at colonies of the aphid Cinara occidentalis was significantly less than the average weight of ants collected in the vicinity of the ant nest. These data and additional observations suggest that small ants are more likely to attend aphids and transport solid food than are large ants. Some large ants may specialize in honeydew transport. Markand-recapture studies showed that workers of Camponotus modoc returned to the same trunk trails and aphid colonies from which they had previously been removed. When relocated to either the base of the tree or to the nest entrance, some workers demonstrated a capacity to recognize the original aphid colony from among as many as eight other colonies in the same tree. Some ants were observed on the same aphid colony for long periods.

Four lines of Aphidoletes aphidimyza (Rond.) were selected for nondiapause (one for 50 generations) under L:D 8:16 and 21 ± 1°C. In three selected lines, diapause incidence dropped rapidly in the first four or five generations, with means of 3–11% thereafter. There was no clear response to selection in the fourth line. Neither morphology nor sex ratio was affected by nondiapause selection in any lines, nor was fecundity affected in the longest-reared line. Reciprocal crosses indicated that the diapause trait was dominant; the effect of relaxing selection pressure was a gradual increase in diapause incidence after eight generations. There was a correlation between increased diapause incidence and slower development in selected lines. Diapause larvae took longer to develop than nondiapause larvae from the same line. Selection for nondiapause under L:D 8:16 with fluctuating thermoperiods was unsuccessful.

Tree size and bark surface area infested in trees killed by the western pine beetle (WPB), Dendroctonus brevicomis LeConte, and the density of attacking and emerging WPB were measured on 91 trees spanning five consecutive generations of the insect. The emergence densities of six natural enemies were also estimated.

Trees averaged 50.9 cm in diameter at breast height (DBH) with a mean height to base of infestation (HBI) of 1.1 m. Heights to top of infestation (HTI) averaged 16.0 m, but were significantly lower in trees attacked by the second [70(1)] and third [70(2)] generations, during synthetic pheromone elution, than in the first [69(3)], or fourth [70(3)], and fifth [71(1)] generations, before and after the treatment, respectively. Infested bark area averaged 2005 dm2 per tree for all generations.

WPB attack density declined steadily from 4.36 beetles/dm2 in generation 69(3) to 0.86 beetles/dm2 in 71(1). Sampling errors ranged from 6.67 to 26.27%, higher than the desired 15% in some cases. WPB emergence in field sticky traps (STIK) followed an opposite trend from 1.66 beetles/dm2 in 69(3) to 5.43 beetles/dm2 in 71(1). Sampling errors ranged from 8.39 to 28.26%. WPB emergence in laboratory rearings (REAR) averaged 4.03 beetles/dm2 with no significant differences among the generations. Sampling errors ranged from 8.20 to 28.77%. Because of inconsistent differences between these two methods of measuring WPB emergence, we have reported estimates of both.

Densities of attacking and emerging WPB were found to be uncorrelated with tree diameter, indicating that density was not a function of tree size and that these two variables may be treated as independent random variables when used in product models to estimate area-wide population totals.

Sampling errors for natural enemies were quite large, ranging up to 400%; therefore few conclusions could be drawn. Predators, in descending order of abundance, were Aulonium longum, Medetera aldrichii, Enoclerus lecontei, and Temnochila chlorodia. Parasitoids were less abundant overall than predators, with Roptrocerus xylophagorum more consistently present and at higher average densities than Dinotiscus burkei.

The suppression treatment was applied during the collapse phase of the population cycle and apparently prolonged that phase for two generations. This delay resulted in the death of an additional 120 trees. WPB productivity increased with decreasing density/square decimetre of attacking beetles. Density of attacking beetles appears regulated by exogenous processes acting immediately in an inverse density-dependent manner. The WPB population at Bass Lake would be released from endemic to epidemic status at the equilibrium point reached at a density of attacking adults of loge 1.65 beetles/dm2. Mortality of the developing within-tree life-stages appears regulated by delayed density-dependent processes, but the details of the relationships differ depending upon the assessment method (STIK or REAR) used.

Reemergence of Ips calligraphus (Germar) was studied at nine constant temperatures from 10 to 37.5°C. The relationship of adult residence time to temperature formed a backward "J"-shaped curve. Median residence times ranged from 6.25 days at 30°C to 163.5 days at 10°C. The distributions of residence times changed with temperature and were nearly uniform at the low temperatures, peaked and skewed to the right at the intermediate temperatures, and nearly symmetric at the high temperatures. Greater than 93% of all adults reemerged at temperatures from 12.5 to 35°C but only 56% reemerged at 37.5°C. Female residence time was about 26% longer than the male. A mathematical function of reemergence rates versus constant temperatures and a distribution function of normalized reemergence times predicted percentage reemergence of a population through time. In simulations, a multiple-cohort procedure was applied using frequency distributions of field attacks to identify the starting times of the model. Model predictions compared favorably with reemergence from three trees in each of four field plots.

The taxonomy and biology of New World species of Chrysolampinae are reviewed with diagnoses given for the subfamily, genera, and species. A key to the species of Chrysolampus and a summary of geographic distribution and information on host and floral associations are presented. Three new species are described from North America (Chrysolampus improcerus, C. luridus and C. elegans); Chrysolampus lycti Crawford is transferred to Perilampus and synonymized with the European species P. micans Dalman. The genus Chrysomalla is recorded in the New World for the first time based on the new species Chrysomalla hesperis. An explanation of the historical biogeography of the genera is proposed that is consistent with Late Cretaceous and Tertiary geological, botanical, and climatic information. It is suggested that the extant species are descendents of elements of a widely distributed arid biota.

Larvae of the mourning cloak butterfly, Nymphalis antiopa (L.), are gregarious feeders occumng most commonly on Salix spp. (willows), Ulmus spp. (elms), Populus spp. (poplars), and Betula spp. (birches), but occasionally on other trees and shrubs (McGugan 1958; Tietz 1972; Howe 1975). They frequently cause noticeable defoliation of ornamental elms; hence the common name, spiny elm caterpillar (Rose and Lindquist 1982).