Laboratory experiments were conducted to determine the effects of bark moisture content on the survival and development of Polygraphus rufipennis (Kirby). Adults and immature stages were reared in white spruce bark of five different moisture contents for 20, 40, and 60 days. Adult activity and brood success were related to the moisture content of the bark with the adverse effects of the drier bark becoming more pronounced with time. After 40 days factors associated with high bark moisture levels, such as fungus and rate of decomposition, may have been responsible for a decrease in survival and rate of development in the moister bark.

A new genus, Misturaphis, is described, with type-species Misturaphis shiloensis new species, from Artemisia caudata Michx. Cryptaphis bromi new species is described from Bromus inermis Leyss. Asiphonaphis anogis Hottes and Frison is declared a junior synonym of Pergandeidia corni Tissot, and P. corni is re-designated as type species of the genus Pseudasiphonaphis, with new name Pseudasiphonaphis corni (Tissot).

In New Brunswick at least nine species of Erythroneura leafhoppers feed and oviposit on birch trees. The appearance and ecological requirements of two species in the subgenus Eratoneura are described.

The composition and variation of hemolymph amino acids in larvae of nine species of the genus Neodiprion were studied. The amino acid pattern was the same in all samples analyzed. Quantitative differences were as great within as between species; hence, hemolymph amino acid data does not appear to be of taxonomic usefulness for this genus.

The optimum temperature for rate of development and survival of immature stages of Coccinella novemnotata Herbst was found to lie between 70° and 80°F. Different photoperiods between 10 and 18 hours per day did not influence rate of development or survival. With a 16-hour photoperiod the mean number of eggs laid per female and mean longevity of females were greater at 70° than at 80°F, but not significantly so. At 90°F egg production was sharply curtailed and most eggs produced were infertile, probably due to inactivation of sperm in the male. Photoperiods of 10, 12, and 18 hours per day induced diapause in a large percentage of adult females; intermediate photoperiods of 14 and 16 hours per day were much less effective. Low temperature and lesser amounts of food available to adult females increased the effectiveness of the short and the long photoperiods for inducing diapause. The stage susceptible to induction of diapause, or conversely the initiation of gonad maturation, was determined to be the young adult from emergence to 7 days of age. The results of experimental data are related to a field study of the biology of this insect in California.

Surveys in unsprayed apple orchards indicated that the oriental fruit moth, whose principal hosts are peach and apple, does not occur in continuing populations on apple beyond the range of commercial peach orchards in Ontario. Moths released in an apple orchard 25 mi from the nearest peach orchard did not result in an infestation after the first winter. High winter mortality due to low temperatures and the unsuitability of apple for the first generation of the moth probably are the main reasons it does not establish continuing infestation on apple alone.

The Rhyacionia frustrana group of pine-tip moths consists of at least three species: true R. frustrana (Comstock), which occurs from Central America and northern Florida north to Missouri and Massachusetts; R. sonia n. sp., present from southern Maine west to southern Manitoba; and R. bushnelli Busck, which occurs from New Mexico north to Nebraska and eastern Montana. Adults of all three species are superficially identical. A lectotype is designated to establish the identity of R. frustrana, and R. sonia is described as new to science on the basis of markedly differing genitalia. R. bushnelli, long regarded as a domestic introduction of R. frustrana, seems more likely a distinct species endemic to the western plains because of its differing overwintering habit and size.

Irradiation of specific regions of 5- to 20-h-old housefly pupae with X-rays shows that exposure of anterior seven segments alone to 1200 r prevents adult emergence, whereas irradiation of posterior region with doses up to 10,000 r has no effect on this phenomenon. It is evident that the target organ, damage to which results in the failure of adult emergence, lies in the anterior seven segments. It is suggested that failure to emerge is due to a direct effect of radiation on the differentiating myoblasts leading to dystrophy of the muscles.

The syntypes of Leucopis annulipes Zetterstedt are described and their identities discussed. A lectotype is designated and the identity of the nominal species is established.

Penenirmus zeylanicus from Megalaima zeylanica and P. rafflesi from Megalaima rafflesii are both described as new. Penenirmus from African barbets are listed and the new species compared with those known from the Picidae.

Suspected predatory invertebrates associated with the larch sawfly, Pristiphora erichsonii (Hartig), on tamarack were confined in cages with sawfly eggs or larvae to determine which species were predaceous. Most of the insects were found to feed on larch sawfly eggs or larvae under these conditions, but very few spiders ate larch sawfly. The amount of food eaten by various predators is presented.

Seasonal population trends of the more common predators and prey available to them were determined from samples of tamarack branches taken at weekly intervals. Associations between the numbers of various predators and prey per 20-branch sample were investigated, and a number of significant predator–prey correlations were obtained. These included correlations between Deraeocoris and sawfly eggs, Plagiognathus and sawfly eggs, and Tetraphleps and sawfly eggs. However, estimates of larch sawfly egg mortality under field conditions showed that egg mortality was largely independent of egg density in the range of populations studied, and showed little relationship to predator density per 20-branch sample. This is because the distribution of larch sawfly egg predators per individual branch was random and appeared to be independent of egg density. Single factor analysis of annual egg populations and egg survival indicated that survival in the egg stage is of no value in predicting population trends of the larch sawfly.

Philodromus praelustris Keyserling and P. cespiticolis Walckenaer have annual life cycles in the Niagara Peninsula. Females of P. praelustris produced up to 12 egg sacs containing a total of over 200 eggs in an insectary but the later eggs did not hatch. Fecundity of females in the orchards appeared to be considerably lower.

There was no experimental evidence that P. praelustris disperses by ballooning though some very young individuals probably do so. All stages disperse by bridging, i.e., by casting an air-borne loop of web that catches on distant objects.

P. praelustris perceives prey by contact or, over very short distances, by vision. Two species of ants were rejected as prey.

An account is given of host acceptance, the influence of temperature on fecundity and longevity, and searching capacity of Chrysocharis laricinellae (Raczeburg), a parasite of the larch casebearer, Coleophora laricella (Hübner).

Fourth-instar case-bearing larvae were the preferred stages for attack. The size of the parasite progeny varied directly with the size of the host. Fecundity of progeny reared from small hosts was significantly less than that of progeny reared from large hosts. Not all parasite adults could successfully oviposit through the tough skin of the host pupa. C. laricinellae showed poor searching capacity. Superparasitism was common at low host densities of the casebearer and resulted in either one parasite emerging or in total parasite mortality. A sex ratio where females predominated resulted when sufficient numbers of preferred stages of the host were presented to mated C. laricinellae. The temperature threshold for attacking hosts was 55°F, and for development of the parasite 40°F. At 50°F the adults lived 4 months on the average.

Therefore C. laricinellae is able to survive in the field without alternate hosts and at very low host densities. The parasite seems to depend on a continuing supply of suitable instars of host species in sufficient numbers to be effective. If C. laricella is the only available host species in the ecosystem the biological control value of this chalcid must be rated as poor.

Gaurax patelainae, a new species reared from the bracket fungus, Polyporus betulinus Bull. ex Fr., is described from Quebec and Ontario.

Chrysops calvus is described as new from eastern North America. It and C. niger Macquart are considered sibling species. A lectotype of C. niger is designated in the collection of the Museum National d'Histoire Naturelle in Paris.

The San José scale, Aspidiotus perniciosus Comstock, died within 84 to 140 days on Winesap apples harvested in early October and placed in standard cold storage or controlled atmosphere storage under laboratory or commercial conditions. The scale died more quickly in controlled atmosphere storage than in standard cold storage. The black caps of the first instar stage were the most resistant to mortality factors in cold storage. It is suggested that Winesap apples infested with the San José scale can be given an inspection certificate for export that guarantees freedom from live scale if the fruit has been stored for specified periods.

The San José scale on Italian prunes died within 34 days when the harvested fruit was kept in standard cold storage.

A complete mortality of the European fruit scale, Aspidiotus ostreaeformis Curtis, on Hyslop crab, McIntosh, or Newtown apples, could not be obtained, in any type of storage.

Studies during 1962–64 showed that the mites Siteroptes graminum (Reut.) and Aceria tulipae Keifer, thrips, and the fungus, Fusarium poae (Pk.) Wr., were not causal agents of silver top in the Peace River region, and indicated leafhoppers were probably not involved. The fact that silver top is controlled with insecticides, but not with miticides, constituted strong evidence for insects as causal agents. In 1963, extensive examination of grasses with silver top revealed minute, inconspicuous punctures, 0.01 to 0.04 mm in diameter through leaf sheaths which were typical of chose made by insects with piercing and sucking mouthparts such as plant bugs. In 1964, attempts to produce silver top by infesting grass plants with plant bugs, leafhoppers, and spittlebugs were unsuccessful for reasons in-explainable. Non-appearance of silver top in either infested or uninfested plants, however, indicated the causal agent was not present in the plants or attached soil when collecred from fields in mid-May. Further studies in 1965 showed that grasses affected by silver top were infested with the plant bugs Stenodema trispinosum Reut., S. vicinum (Prov.), Litomiris debilis Uhl., Capsus simulans Stal., and Trigonotylus ruficornis (Geof.). Experimental infestation of plants with these bugs showed that they fed on stems by puncturing through leaf sheaths and so damaging stem tissue as to cause silver top. In 1966, examination of grasses with silver top from southern Alberta, Saskatchewan, and Oregon revealed punctures in leaf sheaths opposite areas of stem injury, indicating that plant bugs probably cause silver top in these regions.

Laser treatment of larval and pupal stages within cocoons of Neodiprion sertifer (Geoff.) requires an accurate assessment of viability and the antero-posterior alignment of the cocoon content. The use of the candling technique to assess qualitative features of avian eggs depends on the translucency of the egg shell and the differences in light transmission by other elements within it (Romanoff and Romanoff 1949). Transmitted-light methods have been employed for insects within cocoons by Cushman (1913) and Hanna (1935). A type of candling technique different from previous methods and which was developed in the Zoology Department, University of Guelph, enables N. sertifer cocoon content to be ascertained and is herein described.

Volume 99, 1967

Page 447, first two lines, for Jerry A. Mackie read Jerry A. Powell and Richard A. Mackie.