The Nearctic fauna of the subgenus Cerodontha (Cerodontha) Rondani is revised and contains 10 species: C. aduncasp.nov. (Mexico), C. dorsalis (Loew) (widespread Nearctic, eastern Palaearctic, Neotropical), C. gracilis Spencer (western Nearctic), C. inflatasp.nov. (Mexico), C. occidentalis Sehgal (northwestern Nearctic), C. occidoparvasp.nov. (western Nearctic), C. tolucasp.nov. (Mexico), C. trispinata Spencer (Mexico), C. trispinella Spencer (Mexico), and C. trispinosa Spencer (Mexico). All Nearctic species are described and illustrated and a key to species is provided. There are two colour forms of the widespread Nearctic species C. dorsalis: a pale eastern form and a dark western form, although there is overlap in the geographic distribution of the two forms and intermediates exist. The six Mexican species are known from a total of only nine specimens, suggesting that the diversity of this subgenus in Mexico and Central America may be higher than currently known.

This paper presents a sampling plan for estimating numbers of H. postica larvae in the spring growth of alfalfa. A 6-stem bouquet of foliage formed an appropriate sample unit. The pattern of counts for all four instars conformed to the negative binomial distribution, and variance analysis for 89 sets of data revealed that differences between block, plots, and quadrats generally were not significant. For moderate levels of infestation (ca. 12 larvae per bouquet), estimates with acceptable precision may be obtained by taking a single 6-stem bouquet from each of 16 randomly selected ft2 (0.9m2) quadrats within a field, at a total cost of 120 man-minutes.

Sex attractants have recently been reported for several species of Elateridae: Hypolithus bicolor Esch. (Doane 1961); Hemicrepidius morio (LeConte) (Chapman 1964) ; and Limonius californicus (Mann.), Agriotes ferrugineipennis (LeConte), Ctenicera sylvatica (Van Dyke), and C. destructor (Brown) (Lilly and McGinnis 1965). Lilly (1959) demonstrated the attractiveness to males of ethyl alcohol extracts from virgin females of the sugar-beet wireworm (L. Californicus). The attractants appear to be species-specific (Lilly and McGinnis 1965).

The principal injurious species to commercially-grown flue-cured tobacco in Nova Scotia was the dark-sided cutworm, Euxoa messoria Harr. A trace of the black cutworm, Agrotis ipsilon Hufn., was found in one field. The variegated cutworm, Peridroma saucia Hbn., caused minor damage in September. Other species reared from field-collected larvae, and bait and light trap catches, included: yellow-headed cutworm, Apamea amputatrix Fitch; armyworm, Pseudaletia unipuncta Haw.; Amphipyra tragopoginis L.; W-marked cutworm, Spaelotis clandestina Harr.; and the glassy cutworm, Crymodes devastator Brace.

Cutworm larvae damaged young tobacco plants during June through mid-July. The largest infestation encountered during 1971, near the margin of a field, killed 5% and injured 20% of the young plants. Infestations in other fields injured 1 to 3% of the plants, with higher incidences near the borders. A seasonal total of 0.024 cutworm larva injured 0.24 tobacco plant/m2 and destroyed 5 to 10% of the injured plants in experimental tobacco field plots planted in a 4-year-old rye field.

Tobacco trap crop m2 microplots in a rye field attracted 20 to 50 times as many cutworm larvae and had 25 to 40 more plants injured than comparable areas of an adjoining tobacco field. The largest microplot infestation in six fields tested was 1.8 larvae injuring 7.4 plants. The average microplot infestation of 0.5 larva injured 5.6 plants.

Observations, measurements, dissections, and histological preparations were made daily of the eggs and larvae of Bathyplectes anurus (Thomson) while in their host, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae). Observation of development began 24 h after oviposition and ended when parasite larvae emerged from their hosts.

Parasite eggs doubled in length and width during their 3- to 4-day incubation period. Parasite larvae fed on hemolymph initially but later instars preferred the fat body and other tissues. B. anurus has five instars. From 18 to 21 days were required for the larvae to complete development and total development time was 21–25 days at 21 ± 1 °C.

The European Bruchidius ater (Marsh.), first discovered in Massachusetts in 1918, and later in Virginia, is here recorded from Rochester, N.Y. In addition to Cytisus scoparius (L.) Link, its known host in the United States, the insect was reared from seeds of Petteria ramentacea (Sieber) Presl and Laburnum alpinum Bercht. and Presl at the New York locality. All three plants are introductions from Europe. Bruchidius unicolor (Ol.) was recognized in 1965 when it was discovered in British Columbia breeding in the seed pods of Onobrychis viciaefolia Scop. A single specimen, collected in Nicola, B.C., in 1922, indicates that the insect has been present in southwestern Canada for a considerable time.

We investigated whether or not pear ester (ethyl (E,Z)-2,4-decadienoate) attracted adult oriental fruit moths, Cydia molesta (Busck) (Lepidoptera: Tortricidae). The electroantennographic responses of C. molesta to pear ester were recorded and dose–response curves calculated. In laboratory bioassays, the attractiveness of different dosages was assessed in a dual-choice olfactometric arena. The responses of virgin males and females to pear ester in the presence and absence of pear (Pyrus communis L.), peach (Prunus persica (L.) Batsch.), and apple (Malus ×domestica Borkh.) (Rosaceae) shoots were evaluated. Electroantennographic recordings demonstrated that both male and female C. molesta were able to detect the pear ester. In our bioassay, however, pear ester readily attracted males but attracted very few females. The response of males was dose-dependent and they preferred pear ester over apple- and pear-shoot volatiles, whereas no apparent preference between pear ester and peach-shoot volatiles was observed. Therefore, this kairomonal compound could be more effective in attracting C. molesta when applied in orchards of secondary host plants, like apple or pear, than in peach orchards.

A revised generic description of the three larval instars of Omophron is presented. Hypothetical apotypic character states of the genus are: bidentate retinaculum; lacinia subequal in length to galea and apically subspatulate; ligula as long as labial palp; pore LAa located on ligula and seta LA6 on basal third of ligula; setae TI2* and TI7* of middle and hind tibiae located basally; setae UN1 and UN2 flat and about 1.5 times the length of claws; presence of serially paired gland-like structures on abdominal pleura I–VII; hypopleurites not apparent in first instar; apex of urogomphi extended as a small hyaline appendix in first instar; setae PY1, PY2, and PY6 on the pygidium absent. Most of these character states are autapotypic, and no synapotypies were found to indicate a sister group to Omophron.

Mites of the genus Phytoseius Ribaga largely inhabit plants and are at least partly predacious, feeding on tetranychid, eriophyid, and other mites. They probably also feed on pollen, honeydew, and plant juices, as do other phytoseiids that have been studied (Chant 1959; Dosse 1961; McMurty and Scriven 1964). They are not usually found in soil or humus but occur on many kinds of low growing plants as well as coniferous and deciduous trees. They have been collected on all continents and from the arctic to the tropics.

Disruption of mating and of trap capture of spruce budworm, Choristoneura fumiferana (Clem.), has been accomplished in recent years (reviewed in Silk and Kuenen 1984) by disseminating large quantities of the primary components (synthetic) of the female sex pheromone within a forest environment. These components (E)- and (2)-11-tetradecenal (E/Z11-14:Ald) (Sanders and Weatherston 1976) are emitted by virgin female budworm at a 95/5 E/Z ratio (Silk et al. 1980). Unsaturated aldehydes are expensive, tend to polymerize readily (Dunkelblum et al. 1984), and are susceptible to air oxidation and/or photodegradation in the field environment. Analogues, with increased stability and reduced cost, that duplicate the effects of these pheromone components would therefore be of practical value.

Trichadenotecnum alexanderae Sommerman is shown to represent one biparental (= euphrasic) species capable of facultative parthenogenesis (thelytoky) and three uniparental (= obligatorily parthenogenetic) sibling species, as determined by tests for mating, life history observations, and morphological analysis of specimens over the geographic range of the species complex. The name T. alexanderae is restricted to the biparental species because the holotype is a male. The three uniparental species are here named and described as T. castum n. sp., T. merum n. sp., and T. innuptum n. sp. The female of T. alexanderae is redescribed to allow its separation from the three uniparental species. A key to females of the species complex is supplied. All three uniparental species were derived from the biparental ancestor of T. alexanderae. Most collections of populations represented only by females consist of one or more uniparental species. Facultative parthenogenesis is shown to maintain a population of T. alexanderae through one generation only. The biparental species is found not to be restricted geographically to a relictual or peripheral range within the species complex, but to occupy a rather wide, north-temperate distribution across eastern North America.

Studies of the effects of widespread DDT spraying on the parasite complex of the spruce budworm constitute part of a comprehensive program of biological assessment of the New Brunswick forest spraying operations that began in 1952. In the years 1952-1958 these operations covered over 9,000 square miles, practically all the forested area of the northern part of the Province. Almost all areas have been treated two or more times; approximately 80 square miles of the original outbreak area has been sprayed five times, and an experimental plot has been sprayed in each of the seven pears. This has involved the use of over 7,000,000 pounda of DDT, applied mostly at the rate of one-half pound per acre in one-half U.S. gallon of oil solvent.

As the flea fauna of mammals of northern North America becomes better known, its very close affinity with that of temperate and northern Asia becomes more apparent. Many of the genera are holarctic and are associated with holarctic genera of mammals. In a few instances, the fleas of the Old World and the New World are so similar in morphological details and host association that they are regarded as subspecies. For example, Amphipsylla sibirica (Wagner), Malaraeus penicilliger (Grube), Megabothris calcarifer (Wagner), and Hoplopsyllusglacialis (Taschenberg) have representatives in both the nearctic and the palaearctic regions. To this list must now be added Catallagia dacenkoi Ioff, a parasite of Microtinae; this species was described originally (Ioff, 1940, pp. 216-217) from the Altai Mountains of central Russia, and a new subspecies has now been discovered in northern Canada and Alaska.

The postbloom and summer sprays recommended in Florida commercial citrus cultures for management of insect and mite pests and phytopathogenic diseases caused a significant (P < 0.05) reduction of citrus blackfly, Aleurocanthus woglumi Ashby, infesting urban dooryard citrus. There were no observed adverse chronic effects on populations of the parasite Amitus hesperidum Silvestri, or the predator complex consisting of spiders, chrysopids, and coccinellids attributable to the chemical treatments. The absence of chronic pesticide-induced interference with biological control agents was interpreted as an indication of the potential for development of integrated control strategies against A. woglumi should this insect invade commercial citrus areas in Florida.

Four indicators of productivity and quality for the alfalfa leafcutter bee, Megachile rotundata (Fab.), were examined over a 3-year period and the influence of different shelter designs, nesting materials, and 34 environmental variables evaluated. A higher percentage of cocoons per total cells was produced in polystyrene nesting material than in pinewood nesting material. Both nesting materials had similar percentages of tunnels capped or containing cells and total numbers of cells per hive. Shelters with conspicuous orientation patterns or silhouettes had more tunnels capped per hive, tunnels with cells, and greater total cell production per hive than did other shelter designs. The time of maximum bee production varied greatly among the 3 years. Many environmental variables, especially those associated with higher temperature, heat units, and mean actual temperature, had a significant positive effect on bee productivity and cell quality. The information contained in this study may help delineate those climatic areas where this valuable alfalfa pollinator can be most effective, and may assist beekeepers in making management decisions that will improve their operations.

Recent papers by Watt (1959) and Holling (1959) have renewed interest in the use of mathematical formulae as tools in the study of population dynamics. But the usefulness of mathematical formulae can be no greater than the accuracy of the data that are fed into them and at present accurate methods of estimating insect populations are generally lacking.

Estimates made by the method of marking release and recapture, described by Lincoln (1930) and improved by later authors, depend for their accuracy on the thorough mixing of marked individuals in the wild population. The method was used by Richards (1953) to measure populations of the red locust in Tanganyika, and the purpose of the present investigation was to determine its suitability in estimating populations of the migratory grasshopper, Melanoplus bilituratus (Walker).

Long-term, twice weekly, trap catches of the native carrot weevil, Listronotus oregonensis (LeConte) (Coleoptera: Curculionidae), and the introduced carrot rust fly, Psila rosae (Fabricius) (Diptera: Psilidae), were used to test the hypothesis that native populations fluctuate less from year-to-year than those of introduced species, because the native species has had more time to adapt to temporal variability in its habitat than an introduced species. Variability in annual abundance was estimated for 33 years, and for 11-year or 16–17-year subsets of the 33-year time series. Temporal population variability was quantified as PV, a proportion between 0 and 1. The native carrot weevil had a PV of 0.39, less than that of the introduced carrot rust fly with a PV of 0.67, supporting the hypothesis. Generation 1 for both species showed a decline in PV over three decades consistent with the hypothesis that adaptation to variability in the habitat leads to lower PV. Over 33 years, the carrot weevil developed a second generation with a PV of 0.70, higher than that of the first generation, which is consistent with the hypothesis that adaptation is required to stabilise population dynamics in a new habitat, in this case a new temporally defined habitat.