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.

Four species have been described in the apterus-group of the staphylinid genus Tachinus Gravenhorst. One of these, tundrae Poppius, is regarded as a synonym of brevipennis Sahlberg. Tachinus arcticus (Motschulsky) is recognized as a valid species, although earlier works have considered it a synonym of apterus. Tachinus brevipennis is recorded from the Nearctic Region for the first time. A neotype is designated for arcticus and lectotypes are designated for brevipennis and tundrae. Tachinus instabilis Mäklin is transferred to the apterus-group from the fimbriatus-group and recorded for the first time from Siberia. One new species, T. glacialis, is described from Siberia.

A key for identification of the species of the group and a description of the group characters are included. Each of the five species is described and the major diagnostic characters illustrated with scanning electron photomicrographs. A map is included to show the distribution of the species.

Changes in population density were evaluated over an outbreak cycle of the Douglas-fir tussock moth. Growth rate of populations was independent of larval density in the first year, but thereafter became a reciprocal function of density, terminated by complete population collapse at the end of the third year. Through correlation analyses, it was found that density of small larvae accounted for a large proportion of the change in population density between years. This suggests that the local infestations developed largely from resident populations of at least 2 years and not from spread of early instar larvae during the outbreak.

Sampling techniques for all life stages of the apple maggot, Rhagoletis pomonella (Walsh), were developed and their precision and accuracy evaluated. Reliable estimates were obtained for the egg and larval stages (standard error < 10%), but at the low population levels often encountered in the pupal and adult stages it was necessary to accept a lower level of precision (S.E. ≏ 25%). Eggs and larvae were uniformly distributed within trees. Variation between tree quadrants, and sections at different radii from the trunk, showed that stratification within trees was necessary for reliable estimation of the later stages. Predators acting in a heterogeneous environment under the trees were considered to be the major contributors to this variation. The most consistent source of variation was that between trees.

All codling moth larvae, Laspeyresia pomonella (L.), in 100,000 infested apples were killed by fumigation with 32 g/m3 methyl bromide for 2 h at about 17 °C followed by 31–35 days of storage at −0.5 °C. The apples were harvested into bins, fumigated, and placed in a standard cold storage room of a grower’s packinghouse as would be done under commercial conditions. Standard cold storage killed all first and second, and some third, instar larvae in nonfumigated fruit. Cursory sampling indicated that fumigation alone, without subsequent cold storage, could kill all stages. The fumigation and storage treatment did not injure Red Delicious, Golden Delicious, Spartan, Jonathan, or Newtown apples.

The following new pyralid taxa are described: Nehydriris excellens n. gen. and sp. (Pyraustinae), Brazil; Udea tenoalis n. sp. (Pyraustinae), Chile; Synclitodes decoripennis n. gen. and sp. (Nymphulinae), Bolivia and Brazil; Proschoenobius forsteri n. gen. and sp. (Schoenobiinae), Bolivia.

The food habits and biologies of the Miridae, or plant bugs, were studied during research on the arthropod fauna associated with alfalfa, Medicago sativa L., at Ithaca, N.Y., from 1966 to 1969. Seasonal history, population trends, and natural enemies are summarized for the following species found breeding on alfalfa: Adelphocoris lineolatus (Goeze), A. rapidus (Say), Lopidea marginalis (Reuter), Lygus lineolaris (Palisot de Beauvois), Plagiognathus chrysanthemi (Wolff), and P. politus Uhler. Field observations of predation and scavenging by mirids are reported, including feeding on the pea aphid, Acyrthosiphon pisum (Harris); potato leafhopper, Empoasca fabae (Harris); and alfalfa weevil, Hypera postica (Gyllenhal). The most common sources of animal food on the plants were Hylemya flies killed by fungus, and pea aphid mummies containing pupae of aphidiine wasps. It is concluded that utilization of some animal food on their host plants is a common phenomenon among the Miridae.

Lestes congener Hagen overwinters in the egg stage. There is a diapause just before blastokinesis, during which the egg is extremely resistant to low temperatures and desiccation. Post-diapause embryonic development can occur near 0 °C but will not take place until the eggs are wetted as the pond habitat fills in the spring. Hatching does not occur until the temperature exceeds about 5 °C and is highly synchronous. Larval development is rapid and is completed in the field in about 50 days. Emergence of the adults also is synchronous. Sexual maturation requires 3 weeks. Oviposition occurs immediately after copulation while the pair are still in tandem. It takes place only in dry stems of Scirpus. Adaptations of L. congener for life under rigorous prairie conditions are discussed.

Articulated sensilla occur on the pronotum of 100 species in 65 genera of membracids. The abundance of the sensilla and their universal occurrence in this group suggests that sensory reception is a significant function of the membracid pronotum. Bizarre forms of the pronotum may be a result of selection pressure to increase surface area.

Parasitized and unparasitized whitefly populations were sampled on a short-term crop (poinsettia) at 4–7 day intervals until crop harvest. Age-specific whitefly survivorship and parasite activity were evaluated in relation to various biotic and abiotic factors. Three critical factors influenced the outcome of the whitefly–Encarsia formosa interaction during short-term crop production. Commercially acceptable levels of control were achieved on poinsettia by (a) introducing parasites during the first 40 days of crop production, as pupae, when small scales were abundant, (b) introducing sufficient parasite pupae to develop a ratio of one adult parasite for every 30 large whitefly scales, and (c) maintaining an average temperature of 23.3 °C (74°F).

The apple rust mite, Aculus schlechtendali (Nal.), is active on the apple leaves from late May until early August and passes through three generations as indicated by the peak numbers of eggs. This species overwinters as deutogynes under bud scales and crevices in the bark. During the latter part of May the deutogynes lay eggs that develop into first generation primaries, followed by a second generation the latter part of June. Eggs laid by the second generation primaries produce the overwintering deutogynes. Injury to the leaves, mainly bronzing to the ventral surfaces, becomes noticeable early in July. The numbers of A. schlechtendali varied between cultivars within orchards. The differences were not consistent between orchards.

Two new species of aphids are described, Pleotrichophorus villosae new species from Chrysopsis villosa (Pursh) Nutt. in Manitoba, and Chaitophorus longiunguis new species from Salix sp. in Utah.

Seven species originally described in the genus Lygus Hahn are here removed from that genus. The new combinations are: Lygus fortinensis Distant is transferred to Ellenia Reuter, Lygus hospitus Distant and Lygus pellitus Distant are transferred to Dagbertus Distant, Lygus lanuginosus Distant is transferred to Polymerus Hahn, Lygus vicarius Reuter is transferred to Proba Distant, Lygus repletus Heidemann is transferred to Dichrooscytus Fieber, and Lygus irroratus Blatchley is transferred to Lygocoris Reuter. Dagbertus olivaceus Reuter is a new synonym of hospitus.

Sequent sampling of adult males of Atractomorpha sinensis sinensis Bolívar from a laboratory culture has shown that the phallic structures become progressively sclerotized with age, resulting in changes in form, mass, and rigidity which continue throughout adult life. This confirms what had been deduced from previous taxonomic studies. It not only has important implications for taxonomy, but may be a factor affecting reproductive activity of the insects.

Topical application of three analogues of juvenile hormone, ZR-515 (isopropyl 11-methoxy-3,7,11-trimethyldodeca-2,4-dienoate), ZR-777 (prop-2-ynyl 3,7,11-trimethyldodeca-2,4-dienoate), and JH-25 (7-ethoxy-1 (p-ethylphenoxy)-3,7-dimethyl-2-octene) to pre-diapause adults of the white pine weevil, Pissodes strobi (Peck), induced ovarian development and resorption of fat bodies. Control of this species by hormonal induction of reproductive maturity and related metabolic alterations at the onset of winter is suggested.

Two types of field bioassays of the relative attractiveness of various pheromone sources to Ips pini were conducted at Wanakena, N.Y., and at Warrensburg, N.Y. In the first test, the numbers and sex ratios of beetles responding to boring males from New York, Idaho, and their F1 and backcross hybrids graded down in the order of "blood relationship." The intermediate attractiveness of hybrids indicates that hybrids produce pheromones of both parents. In the second test, New York males reared in white pine attracted greater numbers of beetles than those reared in red pine and beetles boring in white pine were more attractive than those boring in red pine.

Although the species that were closely related had similar adult feeding habits, they varied in their specific dietary requirements for mating and for the initiation of oviposition. In Chrysopa lanata, which is not predacious in the adult stage, the females required a protein-carbohydrate diet in order to mate; on the other hand, Chrysopa downesi males and females, which also are not predacious, mated when fed a diet consisting only of sugar and water. Chrysopa nigricornis males and females both required prey (Myzus persicae) before they would mate; whereas Chrysopa quadripunctata and Sympherobius amiculus, both of which are predacious as adults, did not need a diet other than sugar and water for mating.

All five species depended on prey or a synthetic protein-carbohydrate diet for sustained oviposition; however, S. amiculus initiated oviposition when fed only sugar. When the synthetic protein-carbohydrate diet was substituted for prey, 40% of the C. quadripunctata females began to oviposit. The same diet did not promote oviposition in the predacious C. nigricornis adults.

In field studies gypsy moth males were attracted to synthetic cis-7,8-epoxy-2-methyloctadecane (disparlure), the female sex pheromone, and virgin females from 0900 to 2000 (Eastern Standard Time). The greatest numbers of males were lured to the synthetic attractant or the calling female from 1100 to 1500. These periods of male response are longer than reported in previous (1896 and 1932) New England investigations and suggest the possible recent evolution of a new diel rhythm of male sex pheromone response.

The Nearctic species of the elaterid genus Athous east of the Rocky Mountains are revised. Of the 16 included species, two are described as new (neacanthus known from southern Quebec to northern Georgia and orvus known from Nova Scotia to Michigan to Virginia) and two species are transferred from Denticollis, namely, productus (Randall) and quadrosa Becker (as a new junior synonym of A. appalachius Van Dyke). Other new synonymies are: carolinus Van Dyke as a junior synonym of acanthus (Say), erebus Van Dyke of posticus (Melsheimer), and bipunctatus Provancher of productus (Randall). The European species campyloides is known from North America from near Quebec City and in the Canadian Maritime Provinces. Neotypes are designated for the five species described by Say and Randall and for one described by Melsheimer; lectotypes, when needed, are designated for LeConte’s, Melsheimer’s, and Candèze’s species. A key to the species is presented and the salient features and distribution maps for each species are included. Brief notes are given on three western species of Athous: two common species (rufiventris (Eschscholtz) and nigropilis Motschulsky) that are occasionally found east of the Rockies and orophilus Harold, which is known only by the type from the Bitter Root Mountains. Brief discussions are included of two European species, vittatus (Fabricius) and subfuscus (Müller), which have been intercepted at various eastern ports in Canada and the United States, but which have not become established in North America.

A key to macrotype tachinid eggs, actually or potentially occurring on larvae of Heliothis spp. in North Carolina, is provided, based primarily on eggs from reared and trapped gravid adults. This key is probably valid for most of the southeastern United States. Eggs of Winthemiini are described (the common Heliothis parasites Winthemia rufopicta (Big.) and W. sinuata Reinh., and also W. manducae Sabrosky and DeLoach, W. datanae (Tns.), and Nemorilla pyste (Walk.)).