A 3-year study of spatial distribution patterns of insect pests in soybean fields revealed that the Poisson series described the distribution of most species. These species were: green cloverworms, Plathypena scabra (Fabricius); velvetbean caterpillars, Anticarsia gemmatalis Hübner; loopers Trichoplusia ni (Hübner), Pseudoplusia includens (Walker), and Heliothis spp. The Poisson with zeros distribution was second in characterizing the spatial patterns of many of the species. Field counts of Mexican bean beetles, Epilachna varivestis Mulsant, fitted the Neyman’s type A and negative binomial distributions most often.

Ascosphaera apis (Maassen ex Claussen) Olive & Spiltoir, the causal organism of chalkbrood disease in honey bees, has now spread to eastern Canada. Scanning electron and phase contrast microscopy showed that A. apis may be differentiated from A. major, with which it has been confused, by the surface structure of spore balls and by differences in the size of nutriocysts and spores. A. major does not occur in North America.

Interference among females of Nasonia vitripennis (Walk.) reduced consistently though not significantly the percentage of fertilized (i.e. female) eggs that each female laid. The physical aspect of the interference apparently was responsible for part of the reduction; females whose oviposition was interrupted physically in each of six other ways also laid relatively though not significantly fewer fertilized eggs. Neither olfactory stimuli from other females of the same species, nor contact chemical stimuli left in the area earlier by these females, had any effect. Females resumed fertilizing eggs normally after the interference factor had been removed.

In laboratory tests Bioethanomethrin was more than 20 times as toxic as dimethoate when sprayed on nymphs of Melanoplus sanguinipes (Fabr.). Its residual effect on grasshoppers fed treated foliage was relatively insignificant. Toxicity in small field experiments resulted mainly from spray hitting the grasshoppers rather than from their walking or feeding on treated foliage. For 8 days the dimethoate treatment kept numbers of invading grasshoppers significantly lower than those in untreated plots, whereas Bioethanomethrin was ineffective after 2 days. The results indicate that the residual toxicity of the insecticides was of secondary importance in reducing the initial infestation; however, residues do offer a margin of safety against such hazards as poor application, invasion from outside, or continued hatching after treatment.

The balsam woolly aphid, Adelges piceae, has a complex distribution in the crown of trees; The sample universe and sample units are defined, and methods of detecting, monitoring, and measuring population levels at stated levels of confidence, accuracy, and assurance are described. Suggestions are given for sampling aphids on the stems of trees.

The European corn borer, Ostrinia nubilalis (Hübner), has two distinct geographical populations in southwestern Ontario. The time required for diapause termination is the main distinguishing feature. This together with different critical photoperiods for diapause induction explains the occurrence of two complete generations in the southern portion and only one in the northern portion of this region.

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 last-instar larvae of 13 species of Loxostege Hbn. are described and a key included to separate them to species. Notes on the life histories and habits have been added where these are available. One, L. sticticalis (L.), the beet webworm, often causes damage in commercial beet fields. The other species involved in this present work are: L. coloradensis (G. & R.), L. chortalis (Grt.), L. pseudobliteralis Capps, L. marculenta (G. &. R.), L. mancalis (Led.), L. helvialis (Wlk.), L. bifidalis (Fabr.), L. rantalis (Gn.), L. allectalis (Grt.), L. cereralis Zell., L. albiceralis (Grt.), and L. floridalis B. & McD.

The genus Dyscoletes Haliday (Hymenoptera: Braconidae) is revised and placed in the tribe Diospilini. Two species are ineluded, D. lancifer Haliday front western Europe and D. canadensis n. sp. from northern North America. D. soporatus Brues, a fossil, is transferred to Diospilus Haliday. Both extant species have been reared from larvae of Boreus (Boreidae: Mecoptera).

Field studies of male sex attraction rhythms in Argyrotaenia velutinana and five other lepidopterous species reveal that the diel periodicity was modified by ambient temperature. The temperature near the mean hour of attraction appeared to be the most important environmental parameter correlated to the shift in rhythmicity.

Overwintering eggs of the European red mite, Panonychus ulmi (Koch), were killed on McIntosh and Red Delicious apples by 4½-h fumigation treatments with ethylene dibromide. Constant concentrations of 8 mg EDB/1. at 14 °C achieved 100% mortality, and absorption of the fumigant by the apples, the bins, and the chamber was determined so that the amount of fumigant for various size commercial loads could be calculated. Treatments increased scald on McIntosh but reduced it on Red Delicious. Taste and other qualities of the fruit were not affected.

In laboratory studies, an aqueous suspension of a commercial wettable powder formulation of Bacillus thuringiensis var. kurstaki (strain HD-1) containing at least 25 billion viable spores/g and 16000 International Units of Potency (Trichoplusia ni (Hübner))/mg prevented infestations of Indian meal moths, Plodia interpunctella (Hübner), and almond moths, Cadra cautella (Walker), in corn and wheat at a dose of ca. 120 mg of formulation/kg of grain. Treatment of a 100-mm-deep surface layer was more effective than treatments 33 or 67 mm deep and as effective as treatment of the entire grain mass Lack of uniformity in applying B. thuringiensis to the grain kernels caused a small decrease in effectiveness. Dust and bait formulations at about the same doses were as effective as the suspension, but the bait was undesirable because it supported the development of beetle larvae. The formulation was less effective in controlling the Angoumois grain moth, Sitotroga cerealella (Olivier): doses that gave complete control of the Indian meal moth and the almond moth reduced emergence of adult Angoumois grain moths by only about one-third.

Recent advances in genetic insect control theory have made it important to investigate the fitness effects of, and isolation procedures for, autosomal translocations. We isolated 57 autosomal translocations in Drosophila melanogaster (Dipt., Dros.). Twenty-one were homozygous-viable and a few of these were almost as viable as wild-types. From data obtained during the isolation of these translocations it appears that those translocations whose heterozygotes produce high levels of unbalanced gametes have the same range of homozygous viabilities as others. We may infer, therefore, that it is possible to use our simple marker-free isolation method to isolate translocations with sufficiently low heterozygote and sufficiently high homozygote fitness to make population replacement practicable.

This is confirmed in population cage competition experiments. It appears that between 5 and 10% of induced marker-free translocations may be useful for population replacement.

Residue analyses for insecticides were conducted when whole tomatoes and tomato juice were processed from damaged tomatoes that had been in contact with the surfaces of wooden hampers treated with malathion or diazinon. There were 0.18–0.21 and 0.59–0.64 ppm of malathion in whole tomatoes and juice, respectively. No diazinon residues could be detected in whole tomatoes and only traces in juice. The data show that it should be safe to treat tomato hampers with these insecticides in an attempt to control nitidulid beetles that infest damaged processing tomatoes during the period between picking and delivery to the factory.

Laboratory experiments showed that female Lytta nuttalli Say are capable of developing and depositing more than one batch of eggs. The largest number of batches deposited by a female was 5. Batches laid by one female are the same size, and each batch represents one gonadotropic cycle. Most females lay every 4 to 8 days, the most frequent intervals between consecutive ovipositions being 5 and 6 days. The females copulate at least once before the first oviposition and usually again within 24 h after each oviposition. The first copulation stimulates oocyte maturation and probably also deposition of the first batch of eggs. Additional copulations are not needed for the development and deposition of subsequent egg batches, but appear to stimulate egg output. Sufficient spermatozoa are transferred to the female during the one or more copulations preceding the first oviposition to fertilize all the eggs she produces. The largest number of copulations by a male was 9. Males can copulate as frequently as every 24 h, but the most frequent intervals between copulations in virile males are 2 and 3 days. The basic features of the reproductive cycles of male and female L. nuttalli are found in other Meloinae and probably are characteristic of the subfamily. The fairly large quantities of spermatophoral materials from repeated copulations may be important in the nutrition of the female.

Euxoa maderensis n. sp., closely related toEuxoa camalpa (Dyar), is described from Madera Canyon, Arizona. Euxoa serotina n. sp. from southern Texas and Louisiana, is placed near the camalpa group on the basis of the male genitalia and on the structure of the male antennae. Adults and genitalia of the three species are illustrated and a synopsis of Euxoa camalpa is given.

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.

The alar pocket, located on the upper surface of the hind wing of the male monarch butterfly (Danaus p. plexippus) appears to be of a glandular nature, as is indicated by the cells associated with the androconia and as described by authors reviewed in this paper. Two distinct kinds of modified scales are associated with the cells; one (here termed the "patellate scale") has a relatively broad blade and a deeply penetrating stalk while the other (here termed the "poculate scale") is hair-like, fragile, and penetrates the cell membrane for a short distance. The cell of the poculate scale has a chitinous lip that extends above the plane surface forming a cup-like appearance while the patellate scale is associated with a slightly depressed area. In view of the absence of wing scales at the entrance to the lip of the alar pocket of some species of Danaidae, it has been postulated by many authors that this was caused by the insertion of the male hair pencils into the pocket in order to extract the substance emanating from the gland cells. In the present study there was no evidence of scales being removed from the lip of the pocket and hence it is concluded that such does not take place in this species. It is suggested that the poculate scales, being readily dissociated from the cells, may carry the odour to the outside in a manner similar to that of the spherules or "dust" described for Danaus gelippus berenice. Owing to a lack of experimental data, the function of the alar pockets remains ambiguous.

The last larval stadium of the spruce budworm, Choristoneura fumiferana (Clemens), is extended, if infection by an entomopoxvirus is in an advanced stage at the normal time of pupation. The larvae attain an abnormally large size. Part of this increase in size is caused by a proliferation and subsequent infection and swelling of fat body cells.