Earlier work indicated that food plants of the tenthredinid sawflies attacked by Drino bohemica Mesn. and Bessa harveyi Tns. influence host-finding by these tachinid parasites (Monteith, 1955, 1958a). There is a high degree of interaction between stimuli produced by the host larvae and by their food plants (Monteith, 1955, 1958b).

It was observed during field studies that the percentage parastism by B. harveyi of the larch sawfly, Pristiphora erichsonii (Htg.), varied with increasing height above the ground and in different sections of tamarack trees, Larix larician (DuRoi) K. Koch, on which the sawfly larvae were feeding. It appeared that shrubs and trees other than L. laricina influenced host-finding by B. harveyi.

In the Belleville, Ontario, district parasitism of 646 adults of Coccinella trifasciata perplexa Muls. by Perilitus coccinellae (Schrank) (Hymenoptera: Braconidae) was approximately seven per cent and of 363 adults of Coleomegilla maculata lengi Timb. 16 per cent in 1959. Mature parasite larvae emerged from both species of host adults after 20.9 ± 6.2 days of host feeding in the laboratory. The duration of the pupal stage was 10.7 ± 0.4 days and of the adult stage 8.9 ± 5.2 days (22°C. and 65 per cent R.H.). The host beetle usually remained inactive after the emergence of the parasite. Its feet were often entangled in the silk of the parasite's cocoon, and it died within 10 days. P. coccinellae emerged from adults of C. maculata obtained from fourth-instar larvae collected in the field and reared to the adult stage in the laboratory, and also from pupae collected in the field. This is the first authenticated record of this parasite attacking a host stage other than the adult in the field (Clausen 1910), and the second record for this species in Canada (Hudon 1959). Parasitized females of C. maculata laid fertile eggs up to 10 days before the emergence of P. coccinellae.

Ourbreaks of the jack-pine sawfly, Neodiprion pratti banksianae Rohwer, occur in northern Ontario at irregular intervals. Two independent outbreaks within 50 miles of each other – one on Great Cloche Island (McGugan et al., 1952) which lies in the North Channel of Lake Huron between Manitoulin Island and the mainland, and the other near Nairn Centre, approximately 30 miles west of Sudbury, Ontario – offered an opportunity to study the parasitism of this important defoliator. In 1954, when the study was started, heavy defoliation had been reported for several years in the Great Cloche outbreak, and light defoliation had occurred for one year in the Nairn Centre outbreak. Populations decreased in the Great Cloche area but remained relatively constant at a low level in the Nairn Centre area during 1955 and 1956, when the work was completed.

This paper is one in a series on techniques for estimating populations of various stages of the larch sawfly (Ives, 1055; Ives and Prentice, 1958; Ives and Turnock, 1959) to provide's basis for the evaluation of mortality factors. The larch sawfly overwinters in a cocoon in the soil and adults emerge during the spring and summer (Turnock, 1960). This paper describes the methods and results of sampling adults as they emerge from the soil.

Three known species of scale insects belonging to the genus Matsucoccus occur on pine trees in northeastern North America: M. gallicolis Morr., on pitch pine, Pinus rigida Mill., and scrub pine, Pinus virginiana Mill. (Parr, 1939); M. resinosae Bean and Godwin on red pine, P. resinosa Ait. (Bean and Godwin, 1955); and M. macrocicatrices Richards on eastern white pine, P. strobus L. (Richards, 1960). This last species. in contrast with the others, is closely associated with the fungus Septobasidium pinicola Snell. From 1957 to 1959 personnel of the Forest Insect Laboratory, Sault Ste. Marie, and the Forest Biology Laboratory, Fredericton, collected some 500 specimens from 21 areas in Ontario and the Maritime Provinces. These collections, augmented by herbarium specimens provided by the Forest Pathology Laboratory, Maple, from five other areas in Ontario, not only the insect specimens necessary for the dercription of the species, but information on its biology and distribution.

In 1959 a study was conducted in the Whiteshell Forest Reserve, Manitoba, to determine if insectary-reared larch sawfly larvae developed at the same rate as in the field. Data were collected on the rate of frass production in both situations and used as an index of larval development. This was part of a broader study that will be reported on more fully in a later publication, but the immediate results should be of interest to those concerned with studies on ecological life histories of other insects.

Four steps are necessary in constructing and utilizing a mathematical model for control of a specific insect pest. First, a large volume of field data must be collected according to a plan which is sound from both statistical and biological points of view (Morris, 1955). Secondly, a suitable procedure for developing component parts of the whole model and fitting these together must be developed (Watt, ms.). Thirdly, after exhaustive study of available data and testing of equations against these data we must determine the appropriate form of equation to express the action of each type of phenomenon governing dynamics of the pest population. This paper and other in the series (e.g., Watt, 1959) are designed to obtain such formulations. Which phenomena are worthy of smdv for a given pest species will become clear through mathematical analysis of life-table data of the type collected by Morris and Miller (1954). Finally, parameter values are obtained from the data and the equations are manipulated io determine optimum control practices, using methods outlined by Watt (ms.).

In a previous paper (Clark and Brown, 1959) a field cage was described for rearing syrphid larvae and other predators of the balsam woolly aphid. The cages proved satisfactory in the field but some method was necessary to supplement the results with data for individual predators reared in the laboratory under controlled conditions.

In the past, attempts to rear predator larvae in the laboratory on small pieces of infested bark proved unsatisfactory because of the difficulties of keeping the bark moist and suitable for prey development and preventing the growth of moulds on the prey, the bark, and the containers. In most cases when small petri dishes or other containers were used the prey or predators died before rearing was complete or the individuals which survived were unhealthy and not representative of normal prey or predator development.

The species of the genus Hybomitra (Tylostypia) have been most vigorous of the family Tabanidae in colonizing the boreal regions. However, the number of holarctic Tabanidae of this genus is surprisingly few in consideration of the 53 species assigned to North America and the 86 to Eurasia. Only H. sexfasciata (Hine; borealis “Lw.” of authors), H. aequetincta (Becker) and H. epistates (O.S.) in addition to Chrysops nigripes Zett. have crossed the northern Atlantic and/or Pacific Oceans (Philip, 1956). It is not surprising therefore to discover that there is an additional holarctic species which has been known under two different names in the Old and New Worlds.

In a recent communication, Hoopingarner and Farrar (1959) report that the weight of the queen honeybee is genetically controlled, and that a proportional relationship exists between body weight and the number of ovarian tubules. These statements corroborate the findings by Eckert (1934) who found that the number of ovarioles tends to be influenced by hereditary factors. In a subsequent study Eckert (1937) was unable to correlate number of ovarioles with actual brood production. Whether a queen with a greater body weight is capable of laying more eggs than a small and lightweight queen remained to be determined; hence the present study was undertaken.

Two introduced hymenopterous parasites of the European pine shoot moth, Rhyacionia buoliana (Schiff.), are established and widely distributed in southern Ontario: the braconid Orgilus obscurator (Nees) and the ichneumonid Temelucha interruptor (Grav.). Though these two species are economically important in the control of the shoot moth in Europe, they have never become efficient in Canada. A possible cause of their lack of efficiency may be their susceptibility to low temperatures.

This paper is a report on an investigation of the ability of these parasites to withstand low winter temperatures. Laboratory experiments were conducted to determine the resistance of the overwintering larval stages of the parasites to low temperatures. Field observations on the mortality of host and parasites were made at the Waterloo County Reforestation Area, Elmira, near Guelph, Ontario, during the winter of 1958–1959.

In New Brunswick, Ceruraphis eriophori (Wlk., 1848) and Neoceruraphis viburnicola (Gill., 1909) are readily found in spring and autumn on their Viburnum hosts. I have collected both species from the curled leaves of these primary hosts (C. eriophori from Viburnum lantana L. and V. opulus L. and N. viburnicola from V. opulus var. roseum L. and V. trilobum Marsh.) In Colorado, Palmer (1952) recorded borh species from V. opulus var. sterile (= V. opulus var. roseum).

The known secondary host plants of C. eriophori in Europe are species of Carex, Eriophorum, Luzula, and Typha (Börner, 1952); in North America, Cyperus virens Michx. is the only one reported (Palmer, 1952). The secondary hosts of N. viburnicola have not been recorded (Palmer, 1952; Shaposhinkov, 1956), nor has the apterous viviparous female been described.

Macropsis fuscula (Zett.), which is a species common in Europe, was first reported in North America in 1952 when specimens were collected from loganberry on Lulu Island, British Columbia. High infestations persisted on Lulu Island until the destruction of most of the loganberry canes there during a severe freeze in November, 1955. New cane grourth was normal in 1956, hot no leaf-hoppers could be found. Only a few nymphs were found in 1957, but there was an average of 14 nymphs per 100 fruit buds in 1958, and 48 nvmphs in 1959, compared to 32 nymphs during the last season of high infestations in 1955. Re-infestation from hardy wild hosts common in the area probably largely accounts for the rapid re-establishment of this pest on cultivated loganberry.

A study of the biology and control of black flies in the forests of Eastern Canada was conducted on the north shore of the St. Lawrence River, near Baie Comeau, Quebec, from 1954 to 1956. Reference was made to this study by Peterson and Wolfe (1958). Details on the identity of species, and studies on their life histories and habits were reported by Wolfe and Peterson (1959), while the control of black-fly larvae by aircraft spraying was described by West, Brown, and Peterson (in press). Experiments on the control of adult black flies by aircraft spraying are reported in this paper.