The efficiency of an entomophagous parasite may be defined as the capacity which it possesses for distributing its eggs among the available host population in such a manner that its progeny have the best possible chance of survival. This capacity is determined by a number of factors which are, as yet, imperfectly understood. Among these factors are the ability of the parasite female to discriminate between hosts which are suitable for the development of her progeny and those which are not; the relative densities of the parasite and host populations; the habits of the host insect; and the behaviour of the parasite itself during oviposition.

Injury to young jack pine in an experimental plantation at Cloquet, Minn., by a shoot boring insect, Eucosma sonomana Kearfott, stimulated the investigacions on life history, biology and incidence reported here. Notes on life history, biolop and injury are included for two additional species of the subfamily Eucosminae, family Olethreutidae; namely Petrova albicapitana Busck, and Petrova pallipennis McDunnough.

In nutritional studies the proper evaluation of the results depends upon the manifestations of deficiencies. It is essential, therefore, to control all the factors which enter into the nutritional functions of the organism under study. In order to do this, the intervention of symbiotic organisms should be avoided if possible and diets of known chemical entities should be formulated with the ingredients combined in known quantities. Using the cockroach, Blattella germanica (L.), the first condition can be approached, inasmuch as cockroaches can be made aseptic by freeing them from the fauna and flora of their intestinal tract and of their environment following the method described by House and Patton (1949). In the present study the second difficulty has been overcome by using diets formulated especially for this species, among the most important of which is a chemically defined food consisting of known quantities of amino acids, carbohydrates, vitamins, sterols and minerals.

Three mirids, Diaphnidia pellucida Uhler, Hyaliodes harti Knight, and Campylomma verbasci (Meyer), are effective predators of the red mite and probably of the clover mite from early in June until the latter part of July. These three species are the only important predacious mirids under the conditions of the present spray practices in Nova Scotia. Gilliatt (2) has given an account of the life-histories of the three specics and discussed their importance in the natural contrnl of the red mite, and his account need not be repeated here. The three mirids are often the only important predacious species in many commercial orchards during the summer months because of the destruction of I. tiliae and H. faurei by the sulphur sprays emploved around the bloom period. Their presence in such orchards is in itself evidence that neither bordeaux mixture nor flotation sulphur reduces their numbers. Observation on a considerable number of occasions showed that iron carbamate has no effect on these mirids. An opportunity to test some of the common spray chemicals on two of the species was presented in the F. Palmer orchard at Berwick in 1947. Two trees were sprayed with each of the materials listed, and the insects were collected as they dropped on two trays, of 32 square feet each, which had been placed beneath the trees.

“When we consider what immense services hymenopteron insects render to agriculture, it is surprising that those states that have spent already such large sums of money to fight noxious insects and that have lost still more through their depredation have never tried to raise ichneumon flies by the million and let them loose wherever there are any insect pests to destroy.” Felix Gillet., Hort. Comm., El Dorado, California, 1882.

During the course of investigations dealing with the biological control of insect pests of conifers, several species of sawflies were found to be heavily attacked by the tachinid parasite Phorocera hamata A. & W. The present paper describes the immature stages and indudes the life-history of the parasite under laboratory conditions.

About the year 1890 the plant Cordia macrostachya (Jacq.) Roem. and Schult. was accidentally introduced into Mauritius with a consignment of sugarcanes from the West Indies. Later Cordia was spread artificially around the island in an effort to encourage the increase of Tiphia parallela Smith. This parasite was introduced into Mauritius as a possible control agent for the sugarcane root-grub, Clemora smithii (Arrow), and it was found that adult Scoliids fed at the inflorescences of Cordia. (Box 1928). Since that time Cordia has spread considerably and has become a serious pest in Mauritius (for details see Wiehe 1946).

The excellent monographic studies of Brennan (1935) and Stone (1938) on Nearctic Tabanidae and the even more recent catalog of Philip (1947) has placed the study of this group on a firm foundation. The student of this family rarely suffers from a dearth of material since the abundance of individuals of many species, their ease of preservation and their economic importance lead to the collection of long series. As these series accumulate, it sometimes is found that certain species exceed the limits of variation conceded that species, and in other cases what appear to be new forms, may be separated.

In a previous paper (Ullyett, 1949). the present writer outlined a tentative classification of insects serving as hosts to entomophagous parasites. This scheme was based upon the more obvious relationships that exist between parasite and host insect and those which might conceivably have some hearing upon the degree of efficiency with which the females of the former distribute their progeny among available hosts. Five main groups were recognized which reflected the differences occurring between the various kinds of hosts and parasites encountered in the field. Of these, examples have already been dealt with from two of the groups, viz., Group II, in which the host is normally active but is paralysed by the parasite before oviposition, as exemplified by the distribution of eggs by the Braconid, Microbracon hebetor Say among the larvae of Ephestia kuehniella Zell. (Ullyett. 1945); Group IIIA, in which the host is stationary and fully exposed as illustrated by the relationship between the eggs of Ephestia and the attack of Chelonus texanus Cress. (Ullyett, 1949).

Amino acids, the main constituents of protein, are needed by animals for the synthesis of the new body tissue during growth and for the regeneration of old tissues in the adult. They take part in the formation of almost all substances in the body and perform an important function in many physiological processes. When these acids are not available to the animal in sufficient quantities, characteristic metabolic disturbances and pathological conditions result. Amino acids have a similar role in insect physiology and hence have an important bearing upon problems related to insect pathology, toxicology and ecology. Unfortunately, however, very few attempts have been made to investigate the importance of amino acids in the diet of insects.

During the past several vears, the field of insect pathology has “come of age,” so to speak, and has been enjoying somewhat of a revival with regard to the interest taken in it by entomohgists and others. This renewed interest, engendered by several factors, is reflected in the recent establishment of research laboratories and academic courses in various parts of the world. Since there is an increasing demand for information regarding the nature of the field concerned, the type of organization required to maintain it, the training necessary to prepare for it, and the opportunities available to those who wish ro enter it, there is reason to believe that a brief general discussion of these aspects would be of pertinence and value at this time. Although there is a real temptation to wax philosophical concerning our subject, for the present it is perhaps safest to avoid such an approach and to limit our remarks to a rather prosaic presentation of factual material.

During the summer of 1947 n project was initiated with the object of determining the earliest and latest dates of appearance and the period of appearance of maximum numbers of the various species of insects which emerge as adults from the Dundas Marsh, Hamilton, Ontario. Previous to this, during the summer of 1946, observations were made on the occurrence of various insects on the marsh. Such observations were continued during 1947 and are reported herewith.

This is the second of a series of papers dealing with the life-histories of a number of insects attacking the black sage, Cordia macrostachya, in the West Indies, where search is being made for suitable species to use in an attempt at the biological control of the weed in Mauritius (Simmonds 1949).

Schematiza, like Physonota alutacea, is a leaf-eating beetle, sometimes occurring in relatively large numbers on Cordia. It is very heavily parasitized in Trinidad, and as it appeared to be very suitable for introduction into Mauritius it was investigated in detail, both in the field and in the laboratory.

In the course of some studies on chemical control of pests of legume crops it has become desirable to mark honey bees at the hive and, if possible, at the flower. Considerable success has been achieved by the use of the compound fluorescein. It has been found that bees can be dusted with small quantities of fluorescein and that the presence of the material can subsequently be detected by means of a Coleman photofluorometer and by eye. It seems likely that quantitative measurements could be made with a photofluorometer.

During a study of the species of Tubifera known to occur in Maine the author noted that certain specific key characters were not always constant, and often a long series of several species was required before identification was certain. In search of taxonomic characters to supplement those given in literature the author extracted and compared the male hypopygia of several known species of Tubifera. It soon became apparent that this structure deserved more emphasis in the taxonomy of this interesting genus.

In nearly every year our attention is drawn to one or more cases of human myiasis in various places in Alberta. Unfortunately, in every instance where these have concerned infants, the larvae had already been removed and placed in alcohol. We have submitted a number of these larvae co Dr. E. M. Walker, at Toronto University for determination. He has not cared to commit himself by identifying first instar larvae but he classified all specimens which were in the 2nd or 3rd instar as species of Wohlfahrtia. He, further, suggested that they might be meigenii Coq. At the time when he identified them for us, it was believed that this species, though described from Europe, did occur in Western Canada.

The effectiveness of benzene hexachloride (BHC) when applied to pasture sod as a control for June beetles was demonstrated (1) during 1947 at Marmora. Tests were continued during 1948 to determine the control value of the same contact insecticide against second-year, second- and third-instar larvae at the summer-feeding level in sod land.

A block of field plots was laid out in a pasture which was so severely infested by second-year grubs that it was expected to show most extensive destruction of sod before the end of the summer. It was considered as a most suitable area to determine the efficiency of BHC, in terms of sod protection and white grub mortality.

Agrilus anxius Gory has been reported as breeding in numerous species of birches and poplars. Because species of Agrilus are often poorly characterized morphologically, and usually restrict their feeding to one or to a few closely allied species of plants, it has been suspected that two species were confused. Barter, working in New Brunswick, noted that male specimens reared from, or artracted to, birches and poplars were separable allvays by characters of their genitalia. He found also the differences in biology which described below. Study of material in the Canadian National Collection and the U.S. National Museum shows that the genitalic characters hold in specimens associated with food-plants in other localities. Smith (1949, Nature 164: 237), working with material reared in New Brunswick, found that males and females from birches have 22 chromosomes, and those from poplars only 20. Thus it has been demonstrated that two species, one feeding on birches, the other on poplars, have been confused as Agrilus anxius.

In a paper published during the war Reeks pointed out that the sawfly which has caused much damage in the forests of Canada for about twenty years is identical with Lophyrus hercyniae, described by Hartig in 1837. In the same work he proved that Hartig was correct in describing hercyniae as a species distinct from Lophyrus polytomus Htg. Enslin's view that the two species should be united under the name polytomus is quite wrong. Reeks has shown that important biological and anatomical differences exist between them. Benson erected the genus Gilpinia for the species polytomus and for allied species. Reeks was unable to examine the types of the two species, kept in the Hartig collection in Germany, and for that reason he sent to me some specimens of the “European spruce sawfly” from Canada, with the request that I compare them with the types in the Hartig collection. The results of my examination are as follows.

In 1944, as soon as DDT became available, laboratory investigation of its possibilities for control of codling moth, Carpocapsa pomonella (L.) was started at Vineland Station. The work was later expanded and the methods improved until the present technique was evolved; this is still unsatisfactory in many respects but is presented to indicate what may be accomplished in a small laboratory with very limited personnel and equipment and at comparatively little cost.