A revised classification of the subfamily Pimplinae (Hymenoptera: Ichneumonidae) based on characteristics of final-instar larvae is suggested and discussed. On a basis of larval characters the subfamily falls into two tribes: the Pimplini; and the Ephialtini, which consists of the subtribes Ephialtina, Polysphinctina, Poemeniina, Rhyssina and Theroniina.

This is the fourth in a series of papers leading to the development of population models for Hyphantria cunea Drury in New Brunswick and Nova Scotia. In 1961 and 1962 seasonal trends were obtained for moth eclosion, larval development, nest population, parasitism, and other factors. It is concluded that one annual census of nests from a moving vehicle can provide an effective method for comparing changes in population and natural control factors over diverse climatic areas. The timing of the census in each area is important, as well as the collection of nests for data on development, colony size, parasitism, and predation.

The seasonal trends also add support to earlier hypotheses concerning the role of weather in the population dynamics of H. cunea, and reveal the nature of an important interaction between the mortality induced by weather and that induced by the main parasite, Campoplex validus Cress.

For the first time the male of Sirex juvencus californicus (Ashmead) (= Sirex obesus Bradley, new synonymy) is described; the female is redescribed. Biological notes on this subspecies are included, together with a key to the California species of the genus.

Larvae of Hyphantria cunea Drury were reared on early, mid-season, and late foliage collected from the same apple trees. Survival was significantly lower on late foliage and the fecundity of the moths decreased from 604 in the early series to 128 in the late. Half the filial generation was reared under nutritional stress on a deficient synthetic diet and the other half on a very favorable host, speckled alder. Under both conditions there was a strong transmitted influence of parental food quality on the viability of the eggs and on the ability of first-instar larvae to become established on food. The progeny of the late series did not survive beyond this instar. When the filial generation was subjected to nutritional stress, the influence of parental food was apparent throughout the larval, pupal and adult stages, with progeny of the early series having higher survival than those of the mid-season series. However, when the filial generation hail very favorable food, there was no significant difference in survival rates subsequent to the larval establishment period.

The quality of foliage available to univoltine populations of H. cunea depends largely on temperature. Thus, in the development of population models for this species, temperature should be treated as a variable having not only direct effects on establishment and survival each season, but also indirect effects on the quality of the progeny in the following season.

An account is given of the development of a spray nozzle consisting of three steel hypodermic needles coaxially arranged to form three concentric tubes. Air from the inner passage and outer annular orifice atomizes the liquid issuing from the intermediate annular orifice. The resultant effect is an improved control over spray breakup and deposit. A description of the nozzle, its performance characteristics and some application to the study of insect toxicology are presented.

There are two generations of Coccinella novemnotata Herbst per year in central California. The adults of the spring generation aestivate and those of the fall generation hibernate. A field study of the physical and biological factors possibly influencing induction of diapause in the adult was conducted. All stages of the spring generation arc subject to a regime of long, increasing photoperiods and increasing mean temperatures, while all stages of the fall generation are subject to a regime of short, decreasing photoperiods and decreasing mean temperatures. In non-irrigated areas with native vegetation the reproductive cycle of this species is synchronized with the availability of prey species. In irrigated agricultural areas prey species are relatively abundant throughout the summer but the adults of the spring generation still aestivate. It is hypothesized that diapause is induced in the adult by both short and long photoperiods and that intermediate photoperiods are required for reproduction.

The biology of C. novemnotata is described briefly with emphasis on the aggregational behavior of the adult.

The pitted ambrosia beetle, Corthylus punctatissimus (Zimm.), was studied during widespread infestations in sugar maple (Acer saccharum Marsh.) stands of southern Ontario and Quebec. A brief description of each stage of the insect is given, and its life history and habits, as well as the damage caused to the host plant are discussed.

The mycetangia of Corthylus columbianus Hopkins are described. These structures lay immediately below the integument of the pronotum, one in each ventrolateral region. Each mycetangium is a coiled tube 4.69 ± 0.35 mm. in length, cream colored, opening into the anterior coxal cavity. Mycetangia occur only in the male beetle and provide the overwintering storage site and transmission mechanism for associated microorganisms. Smears and cultures of the mycetangia were positive for ascospores and vegetative cells of a yeast, Pichia sp., which coincides with the microsymbiote dominant in developmental chambers of the larvae.

A study was initiated to determine the effects of various constant and alternating temperatures on the survival and development of the immature stages of Culiseta inornata (Williston). Eggs did not hatch at 2° and 5 °C. but at 10°, 15°, 21° and 26 °C. between 83 and 96% hatched. Larvae required up to 239 days to reach the pupal stage at 5 °C. but no adults emerged at this temperature. The optimum temperature for rearing C. inornata was near 21 °C. Temperatures below 21 °C. caused an extended period of development; above 21 °C. high mortality occurred among late instar larvae and pupae.

Tamalia pallida and Tamalia keltoni are described as new from Mexico and compared with T. coweni, the only other known member of the genus. A key to species is given.

Six nearctic species of the genus Chionodes Hübner feeding on Acer (3), Quercus (2), and Salix (1) are dealt with. Keys to the species based on male and female genitalia are presented. Moths and genitalia are described, male and female genitalia are figured, and distribution maps are included. Two new species are described: Chionodes acerella n. sp. from British Columbia, on Acer sp.; Chionodes salicella n. sp. from British Columbia, on Salix sp.

The Atlantic Provinces received many coleopterous immigrants from Europe during colonial times. These immigrants live in man-made habitats, and they show unnaturally restricted distributional patterns. Many were introduced independently to regions about Puget Sound, and there were multiple introductions in the East. Parthenogenesis is a factor in the establishment of imported otiorhynchine weevils. Imported species not previously reported from North America are Abax parallelopipedus (Pill. & Mitt.), Eusphalerum torquatum (Marsh.), Meligethes viridescens (Fab.), and Longitarsus luridus (Scop.). Aphodius tenellus Say is strictly North American and has been confused with the Eurasian species that should be known as uliginosus Hardy. American records of Sitona tibialis (Hbst.) and probably those of S. discoideus Gyll. are based on S. scissifrons Say, which is native to North America. The Alaskan Philostratus ptinoides (Germ.) occurs, evidently as an import, in eastern Canada. New synonymy is proposed: Thes bergrothi (Reitter, 1880) = Enicmus tricarinatus Brown, 1934; Aphodius borealis Gyllenhal, 1827 = A. errans Brown, 1930. Notes are given on the distribution, characters, or nomenclature of other species.

Sixty-nine species of primary insect parasites and 12 associated hyperparasites of the armyworm, Pseudaletia unipuncta (Haw.), are listed. All the species occur in the United States or Canada or both; two have been recorded from the host only in Hawaii.

Observations on 23 of the primary species in Canada are reported with particular reference to host-parasite relationships, general distribution, and the degree of parasitism by the principal species. Seven secondary parasites and their primary parasite hosts are discussed.

Volume 98, 1966

On page 959, line 46, “Fig. 5” should read “Fig. 6”.

Of the 15 Mexican forms included in Coccinella L. by recent authors, nine do not belong to that genus, and the records of four others may be erroneous. A key to six forms that may or do occur in Mexico is given. The two forms that surely occur there, nugatoria Mulsant 1850 and sonorica Casey 1908, are considered only subspecifically distinct from one another. No new names are proposed.

Among the acari there are many species that damage food products (Sinha 1964; Solomon 1936; Cunnington 1965). However, very little information is available on the effect of fumigation on these organisms. Amaro (1963) developed a technique for the fumigation of the eggs of Acarus siro L. that exploits some of the behaviour patterns and preferences of that species. Since this method cannot be applied to Tyrophagus putrescentiae (Schrank), a pest of stored products, an attempt was made to seek other methods by which eggs of this species of a reasonably uniform age could be obtained for fumigation.