Volume 98, 1966

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

Olesicampe (Holocremnus) sp. nr. nematorum (Tschek) has become established at two locations in Manitoba, and has built up rapidly in both. In 1965 at Pine Falls, where it was released in 1961, 61% of the hosts were parasitized in the vicinity of the release point, and at Riverton, where it was released in 1962–1963, 87% were parasitized. A number of characteristics seem to endow this parasite with a marked ability to act against the larch sawfly. These include good synchronization, longevity and searching capacity; low superparasitism; absence of hyperparasitism, and lack of host resistance by encapsulation. O. sp. nr. nematorum has dispersed at least one mile at Riverton and one-half mile at Pine Falls. The percentage parasitism decreases rapidly from the release points to these limits.

A new species of Dirophanes parasitic on Choristoneura pinus Free. is described in comparison with its closest relative D. spinicoxus Viereck and a species it superficially resembles, Phaeogenes cacoeciae Viereck. A key to the three species is included.

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.

Female Nasonia vitripennis (Walk.) discover large housefly (Musca domestica L.) puparia more easily than small ones, and select for drilling a larger percentage of the large ones that they discover. If exposed only to small hosts instead of large ones, the parasites attack more of them in a given time, laying fewer eggs on each. This probably results because changes in parasitized hosts, leading to rejection by the females, occur sooner in small than in large fly pupae. Survival of immature N. vitripennis and of another pteromalid, Muscidifurax raptor G. & S., is greater on large hosts than on small ones. Sex ratio of both parasite species is unaffected by host size.

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.

The construction of a portable and durable knockdown-type cage, designed for rearing larch sawfly larvae in the field, is described.

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.

Six carbamates, Niagara 10242, Niagara 10586, Niagara 10559, carbaryl, Baygon, and Bayer 44646, had negative temperature coefficients of toxicity to second instar nymphs of the migratory grasshopper, Melanoplus sanguinipes (Fab.). The intensity of the negative temperature effect was inversely related to the basic toxicity of each compound. Piperonyl butoxide synergized all six compounds, but the amount of synergism was not related to basic toxicity. The results suggested that several carbamate detoxication mechanisms of varying importance for different carbamates occur in grasshoppers. Whereas all of these mechanisms appeared to be equally affected by post-treatment temperature, they were not all equally inhibited by piperonyl butoxide.

Two braconids, Opius lectus Gah. and O. alloeus Mues., are being reported for the first time in Quebec as parasites of the apple maggot, Rhagoletis pomonella (Walsh).

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.

Queen losses were compared when caged queens with attendant worker bees and caged queens without attendants were used in packages of honey bees being shipped from the southern United States to Canada. When the colonies were hived there was no difference in queen losses in the two treatments.

Chrysocharis laricinellae (Ratz.) mated readily in the laboratory when several individuals of both sexes were held together in a vial. The courtship dance performed by the male is described. Parasite females develop mature eggs 3 days after emergence and are apparently capable of resorbing the eggs if hosts are not available, and to produce new ones after host-feeding. Storage of eggs in the ovary for 5 months at 55°F and sterility (phasic castration) of certain individuals is reported. Longevity of egg-laying females at 75°F was about 1 month less than that of parasites that had been denied contact with hosts. Odor apparently plays little or no role in the location of the larch casebearer larvae by C. laricinellae, but chemical surface stimuli seem to exist on the surface of a mine or case of Coleophora laricella (Hbn.). The parasite is also stimulated by vibrations of the host in its case. The oviposition and host-feeding pattern of C. laricinellae is described. Host-feeding on fourth-instar larvae of the larch casebearer contributed little to host mortality.

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.

Behavior patterns associated with egg-laying are proposed as a potentially valuable source of taxonomic characters for blister beetles that excavate oviposition chambers in the soil. Methods of digging the burrows and covering the eggs are complex and stereotyped and often differ considerably from one species to another. Relationships among species of Lytta, Linsleya, and Epicauta suggested by their nesting behavior are compared with those indicated by other characteristics.

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.

Aulacorthum dorsatum new species is described from British Columbia. Its only known host plant is salal, Gaultheria shallon Pursh.