Field studies conducted in cherry orchards of the Willamette Valley, Oregon, indicate that diapausing pupae of the western cherry fruit fly, Rhagoletis indifferens Curran, overwinter in the soil at a depth of 1–4 in. Relatively very small numbers of pupae were collected from surface debris and soil samples taken at a depth of 6 in. and below. The number of flies emerging from different soil depths indicated that removal of the top 6 in. of soil caused a 99% reduction in adult emergence, while the removal of the top 1 in. of soil had no effect.

Larvae of the family Chrysopidae possess characteristics useful in classification at the species, genus, and subfamily levels. This study, which initiates a comprehensive analysis of chrysopid larval systematics, describes the important external characteristics of the family and discusses those features which vary between taxa within the family.

The carnea- group of the Chrysopa, subgenus Chrysoperla, includes six described North American species, most of which are important in pest management. This paper defines the series of characters unique to the larvae of this taxon, presents a key to all larval instars of the six species, and describes the three larval instars of each species, most of which were previously undescribed.

The earliness or lateness of the hatching period in Melanoplus sanguinipes (Fabr.) affects the type and amount of damage to the crop and the timing of control measures. An empirical model for prediction of hatching at each decile of egg populations was developed by multiple regression using daily maximum air temperatures for a unit interval of 5 days from 2 March to 29 June and embryonic development in the preceding fall. The model accounted for a maximum of 96% of the variance in hatching date. It showed the average effect of a unit change of 1° of daily maximum temperature for each of the 24 5-day intervals on the number of days to hatch. The time and pattern of hatching of the major bulk of egg population was dependent mainly on spring temperature; however, fall embryonic development accounted for considerable variation in hatching time especially of the less developed eggs. The implications for population growth and certain assumptions made during the analyses in this study are discussed.

Pinus rigida trees exposed throughout the study to chronic gamma irradiation were inventoried to determine the intensity of attack by the bark beetles Ips grandicollis and I. calligraphus. Beetle developmental success was determined from bark samples by estimating the percentage of the cambial surface utilized. Trees killed by high radiation doses were attacked by the beetles even though radiation exposure proved lethal (> 500 r/day). In dead trees receiving lower doses adults survived but progeny were killed during different stages of development, depending on the dose rate. Developmental success was less on the exposed side of each tree than on the shielded side. Species with short life cycles have a survival advantage over those that have a long life cycle when exposed to chronic irradiation.

Juvenile hormone analogues (JHA) were fed in an artificial diet to laboratory reared Porthelria dispar (L.) larvae. The analogues used were: I: Stauffer R-20458; 1-(4′-ethylphenoxy)-6,7-epoxy-3,7-dimethyl octene. II: Altozar®. III: Hoffmann-La Roche Ro 8-5497; 10,11-epoxy-3,7,11-trimethyl-1-(2-propynyloxy)-2,6-tridecadiene. For JHA I and II mortality occurred primarily during the larval and pupal stages with overall EC50 values from 0.19 to 0.43 p.p.m. in the diet. JHA III was not toxic. The log-probit dose–mortality curves showed low slopes. Morphologic aberrations in treated larvae and pupae were observed.

Arthropod population densities were evaluated from nests of colonial ring-billed gulls (Larus delawarensis). Each nest was considered as being an island microhabitat in which a measurable population was concentrated. Despite significantly greater numbers of arthropods in larger than in smaller gull nests, population densities per nest dry weight were similar.

During 1972, spruce budworm infested white spruce and balsam fir trees were sprayed aerially with a low dose of fenitrothion (0.25 oz AI/ac), entomopox virus (EPV) at 7.6 × 1010 polyhedra/ac, nuclear polyhedrosis virus (NPV) at 2.7 × 1011 polyhedra/ac, or each virus–fenitrothion combination. Fenitrothion (active ingredient), NPV, and EPV deposited at ground level at 5%, 31%, and 42%, respectively, of the amounts emitted.

In the year of application, NPV + fenitrothion was highly effective in population reduction and foliage protection especially on; balsam fir although a higher virus infection rate was found on white spruce than on balsam fir. EPV + fenitrothion also provided a high level of foliage protection and apparently reduced surviving female:male sex ratio to 1:2 compared with the normal 1:1 ratio. NPV + insecticide caused highest larval mortality, highest incidence of virus, lowest rate of moth emergence, fewest progeny, and lowest rate of progeny survival. The natural incidence of microsporidia was low in all plots.

In the year following application, the NPV + insecticide treated plot again showed lowest population density, highest larval mortality and incidence of virus, and low defoliation and egg mass density. However, there was a higher proportion of viable eggs deposited than in the previous year. Egg parasitism by Trichogramma minutum increased by 1.5 to 4.2% in plots treated with virus only and declined by 1.6 to 10.5% in insecticide treated plots and by 1.2% in untreated check plot. The transmission of the virus from one year to the next is considered to be of paramount importance in the future use of this pathogen in spruce budworm control.

The course of the host–parasite relationship between Pollenia rudis (Fabr.) and Eisenia rosea (Sav.) is determined largely by the behaviour of the earthworm host, which in turn depends on soil conditions. Encystment of the host, which occurs mainly at low levels of soil moisture and bulk density, increases the success rate of the infection. Autotomy of infected segments by the host occurs in a higher percentage of active than encysted worms.

The following new genera and species are described: Alatuncusiodes n. gen., type-species A. korytkowskii n. sp., Peru; Argyrarcha n. gen., type-species Boeotarcha margarita Warren, of which Hyaloplaga ankarampotsyalis Viette is a synonym; Mecynarcha n. gen., type-species Mecyna apicalis Hampson; Cymbopteryx pseudobelialis n. sp., Bolivia; Cymbopteryx diffusa n. sp., Mexico; Noctueliopsis decolorata n. sp., Baja California, Mexico; Noctueliopsis grandis n. sp., Baja California, Mexico. Scybalista subductalis Walker is transferred to Alatuncusia Amsel; Thelcteria ysticalis Dyar is transferred to Schacontia Dyar; Edia extralinea Dyar is transferred provisionally to Cymbopteryx Munroe.

Two chalcidoid species, previously known only from Europe, are reported from North America for the first time. Habritys brevicornis (Ratz.) occurs in Quebec, Ontario, and British Columbia. Psilonotus achaeus Wlk. (= Eutelus betulae Grit., new syn.) occurs in Ontario, New York, and Michigan; it parasitizes Oligotrophus betulae Winn. (Cecidomyiidae) in seed of white birch.

An absolute requirement for sugar could not be shown but laboratory rearing experiments using artificial diets have demonstrated a definite increase in weight of adult spruce budworm (Choristoneura fumiferana (Clem.) Freeman) with increasing dietary levels of certain sugars. Males exhibit a threshold of 0.9% soluble sugars above which higher sugar levels produce no further increases in size. Females respond with an increase in size up to 4.0%, the highest level tested. Generally, faster development rates accompany greater mature weights on diets with higher nutrient levels.

Maltose, raffinose, glucose, sorbitol, sucrose, and fructose are all good sugar sources. Galactose and trehalose are only slightly inferior. Lactose, ribose, melibiose, xylose, mannose, arabinose, and melezitose in the diet are little different from the sugarless control. Sorbose is somewhat inhibitory.

Results of transfer experiments confirm the importance of sugar particularly during late larval development. They also indicate that a high protein diet during early instars has a significant effect on development rates. These results suggest that departure from the normal synchrony of development in the insect and its host can affect both rate of development and mature size of the insect.

The parasitic juveniles of mermithid nematodes attack a variety of hosts from 15 insect orders (Welch 1963, 1965). Little is known of the extent to which they are parasites of Miridae. Menzel (1922) and Cobb et al. (1927) recorded parasitism of the bug Helopeltis theivora Waterh. by Mermis sp. and by Agamermis paradecauta Steiner, respectively. A related mirid, H. antonii Sign., was reported parasitized by Mermis sp. (Menzel 1922), and by A. paradecauta and Hexamermis microamphidis Steiner (Steiner 1925). Recently King (1969) found that the mirids Sahlbergella singularis (Hagl.) and Distantiella theobroma (Dist.) were hosts of the genus Mermis Dujardin.

Five new genera and 27 new species of tachinid flies from North and South America are described as follows: Acemya favilla n. sp., Actinodoria argentata n. sp., Adoryphorophaga luxatura n. sp., A. secutoris n. sp., Aphantorhapha pulla n. sp., Belvosia naccina n. sp., Calolydella summatis n. sp., Catemophrys sororcula n. sp., Chaetona pictilis n. sp., Doliolomyia n. gen. (type-species D. thessa n. sp.), D. alactaga n. sp., Echinopyrrhosia arrogans n. sp., E. pellacis n. sp., Eomeigenielloides n. gen. (type-species E. segestris n. sp.), Euceromasia sobrina n. sp., Euempheremyia melotris n. sp., Eulasiopalpus mirimodis n sp., Eutrapelus n. gen. (type-species E. atlixcoensis n. sp.), Leucostoma fallax n. sp., L. politifrons n. sp., Lindigepalpus bogotensis n. sp, Lindigia oriunda n. sp., Melanepalpus meraculus n. sp., Myioclura n. gen. (type-species M. necopina n. sp.), M. melusina n. sp., Myiophasia harpi n. sp., Technamyia n. gen. (type-species T. cinereola n. sp.), Trichosaundersia callithrix n. sp.

Twenty-four species of parasitoids were found associated with the large aspen tortrix in interior Alaska. Keys are supplied for determining adults and, in the absence of adults, the parasitoids based on host stage and on late-instar larval remains. Brief biological and descriptive notes are given for each species appearing in the key.

Four insect developmental inhibitors were tested against different stages of the apple maggot, Rhagoletis pomonella (Walsh). ZR515 was the most effective compound, completely inhibiting adult development from larvae and pupae treated at concentrations of 10 μg. Larvae were more susceptible than pupae. Sensitivity declined as pupae aged. Dissection of puparia showed a pupal/adult intermediate, usually with some adult characters developed in the thoracic region. ZR512 inhibited adult movement from larvae or pupae exposed to concentrations of 1.0 mg whereas R20458 gave inhibition of adult development at 10 mg concentrations. RO 20-3600 inhibited adult development from larvae exposed to concentrations of 10 mg. ZR515 and ZR512 applied to fruit had little effect on larval development but numbers of adults emerging from pupae from treated fruit were reduced. Adults from all tests produced viable eggs in the following generation.

Four new species of aphids are described from Manitoba: Dactynotus brevitarsus from Solidago sp., Myzus valuliae from wild strawberry, Fragaria vesca L., Amphorophora stolonis from dewberry, Rubus pubescens Raf., and Nasonovia (Hyperomyzus) sandilandica from Crepis tectorum L.

The functional response of Spalangia endius Walker was described by a linear relationship between attack rate and density of house fly pupae. S. endius searched well at higher host densities and in 72 h, appeared capable of attacking more than 80 pupae per female under laboratory conditions. The response of Muscidifurax raptor G. & S. was quadratic as poor searching ability limited this parasitoid’s attack rate at high host densities. Individual parasitoid efficiency of both species was reduced by intraspecific competition when parasitoid density was increased.

Cybalomia angustalis Dognin is transferred to Vdea Guenée; Udea annectans n. sp. is described from Bolivia.

Populations of Tribolium castaneum (Herbst) exposed to sublethal doses of irradiation (0.5–4.0 krad) each generation for as many as 25 generations had decreases in reproductive capacity and increases in sterility that were positively correlated with the size of the dose per generation, but not with the number of ancestral generations treated. Exposure of the selected populations to an acute dose of irradiation (2.0 krad) revealed no increase in tolerance to irradiation even after 25 generations of selection. Radioresistant populations would probably not arise from fertile survivors of irradiation disinfestation of bulk grain.

Esterases present in the hemolymph of last instar Heliothis zea (Boddie) were separated by polyacrylamide gel electrophoresis. Four systems, all polymorphic, were observed. One system, Est-II, appeared especially suited for the study of some of the important population processes of this species; these include host–plant relations, migration, and the effects of environmental pressures such as pesticides on the species.

Est-II was classified as a carboxylesterase, being sensitive only to organophosphate inhibitors. Dichlorvos at 10−5M completely inhibited Est-II activity.

Populations collected from corn from Tifton, Ga., and in two locations in Illinois, at approximately the same time were very similar genetically when compared on the basis of Est-II allele frequencies. A population collected from leguminous hosts in Tifton, Ga., at the same time as the above three populations was different genetically.

Est-IIc, an allele normally rare or absent in the populations studied, was present at a high frequency in one Urbana population collection. Est-IIc may be useful in studying the long-range dispersal of H. zea.