Biologists in general, and entomologists in particular, have published many data of the ‘percentage mortality’ type. It appears to be a natural tendency in the ecological study of an insect to attempt to measure the degree of mortality caused bv difierent factors. Early publications listed many figures on ‘percentage age parasitism’ because it was one of the easiest mortalities to measure. More recently, as betrcr techniques were developed for population sampling and mortality assessment, it has been possible to derive mortality data for other factors. Notable progress has even been made with such difficult problems as measuring the mortality caused by avian, mammalian, and invertebrate predators. Despite these developments, life tables generally show some residual mortality that cannot be attributed to a specific factor. Frequent population measurement can establish the exact time of such mortality, however, while concomitant work on behaviour, physical ecology, and inherent factors can provide very useful clues as to what intrinsic or extrinsic factors it may be related. Fairly complete life tables are already available for natural populations of a few species, and will no doubt become available for additional species from time to time.

This paper describes the seasonal history and habits of three borers of the genus Dioryctria that destroy red pine cones in Ontario. These insects, as a group, generally rank second in importance as cone destroyers to the cone beetle, Conophthorus resinosae Hopk., which was the subject of the first paper in this series (11), and are presented together because of their family relationship and the similarity of their habits.

On October 16, 1956, during a routine monthly check of the Nurses Residence, Selkirk Mental Hospital, Selkirk, Manitoba, a professional exterminator noticed “thousands” of very small insects in a basement office. A number were submitted to the writer for identification and found to be aphids, which were later very kindly identified by W. R. Richards, Insect Systematics and Biological Control Unit, Ottawa, as Sipha agropyrella (H.R.L.). Richards stated (in litt.): “This is the first record of this species west of Ontario.” MacGillivray (1956) records the finding of this species in 1950 in New Brunswick as a new record for North America.

This paper describes the main anatomical features of the adult nervous system of the Douglas fir beetle, Dendroctonus pseudotsugae Hopk. The study on which it is based was carried out to provide a background for further work on the nervous system and as part of a program of investigation of the physiology and behaviour of scolytid beetles.

Extensive comparative studies of coleopterous nervous system were made long ago by Blanchard (1846) and Brand (1879). Their descriptions of scolytid material are sketchy and brief, however, and because we can find no other treatment of the nervous system in the Scolytidae we are presenting this brief report on our work.

Methods of rearing various stages of the pale western cutworm, Agrotis orthogonia Morr., in the laboratory have been described (Hocking, 1952; Jacobson, 1952; King and Atkinson, 1927; Lindsay. 1954; Parker et al, 1921; Seamans and McMillan, 1935). From these a very satisfactory method has been evolved at the Lethbridge laboratory that this insect to be reared for several generations, providing a source of experimental material at any stage of development. The rearing may be done very satisfactorily a t room temperature but, if desired, the method is adaptable to rearing at various conditions of constant temperature and relative humidity.

During hurricane “Hazel”, on October 15, 1954, the Holland Marsh, Bradford, Ontario, was flooded with water to an average depth of about four feet. Some sections were covered by more than 10 feet of water and remained flooded for two to three weeks. Data from population studies on the carrot rust fly, Psila rosae (F.), conducted in the area by Miss J. B. Williams of the Ottawa laboratory from 1951 to 1953 and by the author in 1954 and 1955 provided an opportunity to determine whether the flood had affected the abundance of the insect.

Pyrausta unifascialis (Packard) is the Nearctic representative of 3 closely knit group which ranges throughout the Holarctic Region and into northern South America, and which includes such species as P. aerealis (Hübner), P. limbopunctalis (Herrich-Schäffer), P. sardinialis (Guenée), P. canotinctalis Hampson, P. postalbalis South (=P. aerealis glauculalis Caradja, new synonymy), and P. polygamalis (Snellen). Study of the considerable series of P. unifascialis in the Canadian National Collection shows that four North American subspecies are recognizable, two of them undescribed.

Trials to determine the extent of fruit protection given by spraying spores of Bacillus cereus Frankland and Frankland on apple trees exposed to natural attack from the codling moth, Carpocapsa pomonella (L.), were carried out in the experimental apple orchard of the Entomology Laboratory at Summerland, British Columbia. Heavy injury was expected there on trees not receiving commercial insecticide applications. Ten test and ten check trees were chosen at random. Check trees received no treatment of any kind. Test trees were treated with six sprays between May 26 and June 29, 1954, and five between August 5 and September 8, 1954.