Hygro-receptive sensilla have been found on the antennae of fruit flies (1), spider beetles (2), cockroaches (3), wireworms (5), ticks (6), mealworm beetles (8), flour beetles (11), and body lice (16). Two types of antennal sensilla, the basiconic and the coeloconic, have been identified as hygro-receptors of the grasshoppers, Melanoplus differentialis (Thos.) and M. mexicanus mexicanus (Sauss.) (12, 13). This paper describes the antennal sensilla of Melanoplus bivittatus (Say) and discusses their function.

The pale western cutworm, Agrotis orthogonia Morr., a pest of crops in the plains areas, occurs in central Alberta and Saskatchewan in Canada southward to various areas of Oklahoma, Texas, and New Mexico in the United States. It has been suggested that in the prepupal stage this cutworm is able to adapt itself to a wide range of climatic and geographic conditions and to retain a univoltine life cycle. The investigations reported here were made to determine the effects of temperature, moisture, and larval weights on the duration of the prepupal and pupal stages.

In the course of ecological work on black flies, some first-instar larvae that proved to be those of a species of Prosimulium were collected from trailing grass leaves in three streams in the Gatineau hills, seven miles north of Ottawa, in October, 1958. These larvae lack the head-fans (premandibular organs) characteristic of the later instars and of the larvae of most other black flies, and in this and other respects resemble those of Gymnopais Stone and Twinnia Stone and Jamnback. There is no reference in the literature to such a form and it seems clear that the first instar of Prosimulium was hitherto unknown.

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.

Several species of native syrphids have been found to prey upon the introduced balsam woolly aphid, Adelges piceae (Ratz.), in New Brunswick and three of these, Syrphus torvus O. S., Metasyrphus lapponicus (Zett.), and Neocnemodon coxalis (Curr.), are sometimes very common. As part of a long-term study of the biological control of the balsam woolly aphid by native and introduced predators, the life histories, natural control, population fluctuations and control value of these native syrphids have been investigated.

The history of the black-headed budworm, Acleris variana (Fern.), in the western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests of coastal British Columbia is one of recurring cycles of outbreaks. The latest cycle occurred from 1952 to 1957 and was represented by three main outbreaks in the Portland Canal area from Prince Rupert to Stewart, the Queen Charlotte Islands, and on northern Vancouver Island. Previous to this, groups of West Coast outbreaks were recorded from 1940 to 1945, and from 1927 to 1931 (Prebble and Graham, 1945a).

In the description of the Byron Bog (Judd, 1957c) it was pointed out that one method of collecting insects in the bog was to make a circular sweep with an insect net, held at arm's length, through the tops of the bushes in the Chamaedaphnetum calyculatae association. The net used was one with a rim twelve inches in diameter and the radius of the circle over which the sweep was made was six feet. A single sweep was made each day from Itlay 15 to November 15 in 1956 and all the insects collected each day were sorted and counted. The dav of maximum blooming of Chamaedaphne calyculata was May 21 and the day of last blooming was June 1 (Judd, 1958a). Thus there was a period of nineteen days, from May 15 to June 1, when the plants were in bloom while the sweeping was in progress.

The first lots of asparagus received at processing terminals in the Shelby, Michigan area in May of 1959, were heavily contaminated with case-bearer larvae of the family Coleophoridae. Various methods were unsuccessful in an endeavor to dislodge the larvae from the spears. As a result, a detailed investigation was initiated to ascertain the origin, life history, and possible control of this insect.

There are five known species of the genus Hylobius in North America. These are H. congener Dalla Torre, Schenkling and Marshall, H. pales (Herbst), H. radicis Buchanan, H. pinicola (Couper) and H. warreni Wood. Buchanan (1934) recognized the first three species and indicated that “there might be one or two additional races or species”. He also stated, “Hypomolyx piceus Deg. is placed in Hylobius in the Junk catalog; it differs from the above 3 in its untoothed femora.” Wood (1957) recognized H. pinicola (Couper), invalidated the generic name Hypomolyx, and erected a new species, Hylobius warreni. He briefly described the new species and presented a taxonomic key by which it could be distinguished from H. pinicola and a Eurasian species, H. piceus (DeGeer). It is now clear that Hypomolyx piceus as referred to by Warren (1956a, 1956b) actually consisted of two species, Hylobius pinicola and H. warreni.

The sunflower maggot is native to North America. It has been recorded from Maine and New Brunswick through Quebec to Alberta and California and as far south as New Mexico and Florida. It was collected by Criddle at Aweme, near Treesbank, Manitoba, in 1905 and is known to have been present in cultivated sunflowers in southern Manitoba since 1944. Heavy infestations have occurred since 1948.

In Western Canada, Melanoplus bilituratus (Wlk.) may hatch from early May to mid-July, depending on seasonal conditions. Little information is available on the relationship of time of hatching to population growth except that grasshoppers emerging too early in the spring may be destroyed by adverse weather that often occurs at this time (Shotwell, 1941). Also, it has beenassumed that grasshoppers hatching late in the summer mature too late to contribute much to general population growth.

Sampling to obtain valid estimates of the degree of parasitism in natural populations of insects presents a difficult problem to the quantitative-minded investigator. The method used must adhere to the principles of random sampling, yet it must be truly representative with respect to the occurrence of the parasite in its sampling universe, the host insect, in both time and space.

During recent years intensive studies have been carried out on the black-fly fauna of Utah and of Wyoming by the senior author and junior author respectively. As a result of these investigations a number of new black-fly specieswere collected, four of which are described below.

The following descriptions and measurements were made from alcohol-preserved specimens, hut where available, pinned, dried specimens were also used in preparation of the descriptions. Most of the drawings were made from slide mounts with the aid of a Ray-O-Scope microprojection apparatus; the others were made from cleared spechens retained in glycerin and were drawn with the aid of a squared-grid ocular in a stereoscopic microscope.

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.

Parker et al. (1955) reported the spectacular outbreaks and migrations of the migratory grasshopper, Melanoplus bilituratus (Wlk.) in 1938 and 1939 in the north-central states of South Dakota, North Dakota and Montana, U.S.A. They recorded the extension of the flights northward into the Canadian provinces of Manitoba Saskatchewan and Alberta, and mentioned that the progeny of the migrants invading southern Saskatchewan in 1939 moved further north in 1940.

Since 1947, when the bramble leafhopper, Ribautiana tenerrima (H.-S.) (rubi Hardy, misella 13011.), was first reported in North America near Victoria, B.C., it has become a serious pest in cane fruit plantings on southern Vancouver Island and the lower Fraser Valley. Hoth nymphs and adults suck the sap from the leaves, producing a white stippling on the upper surfaces (Fig. 1). In a dry season a severe infestation causes many leaves to become curled and appear burned. The canes lack vigor and the size of the fruit is reduced. This is a report on a study of the life history and behavior of the species conducted at Victoria from 1953 to 1957.

In spare moments during and after the Xth International Congress of Entomology I collected many aphids in Canada. The present paper contains descriptions of some of these that appeared to be new, while two of the leading Canadian aphid specialists permitted me to add descriptions of some more new species that were present among the material that they submitted for identification.

Larval anatomy as an aid to understanding taxonomic and phylogenetic relationships of Scolytidae has been discussed in an earlier paper (Thomas, 1957). Before an appreciation of relationships can be gained, however, comparative descriptions of many species must be compiled. As representantye groups of species become available, the immature stages of genera will be described, defining characters of value in separating component entities.

A previous paper (Canadian Entomologist 40(2): 81–89, 1958) considered the general nature of an air-borne scent and suggested a mechanism by which a flying insect could be guided towards the source of an attractive odor. At first sight, it might seem that a repellent is merely an attractant with a minus sign, but this is an oversimplification, because an attractant may and often does bring the attracted insect in from a distance of a few miles, whereas the repellent has done its work if it removes the unwanted insect to a distance of no more than a few inches. The quantitative difference in the effect is so great as to imply a qualitative difference in the mechanism. On the naive view, the attractant draws the insect upwind and therefore the repellent should drive it downwind. A qualitative difference implies some third result, possibly a tendency to move the insect across the wind. This may, in fact, be the way repellents work in some circumstances, but it can scarcely be the whole story and is mentioned at this point merely to bring out the inherent difference between the attraction and repulsion of insects by odors.

Wings, legs and antenna unmodified; frons flat and oblique, yellowish buff dorsally, fuscous on sides; labial palpus fuscous laterally with some orange scaling, yellowish buff dorsally, whitish buff at base beneath; maxillary palpus prominent, fuscous tipped with orange; proboscis orange-scaled at base; eye fuscous brown; antenna light brown; vertex rough-scaled, light yellowish brown; thorax above light yellowish brown abdomen ahove light buff, with some yellowish scaling; body beneath whitish buff, darker posteriorly; legs yellowish buff above, whitish buff beneath. Forewing above translucent dull yellow; an oblique fuscoits dash at base; an orange, inwardly and outwardly fuscous-bordered, outwardly oblique sub-basal band, beginning at R, indistinct in cell; an antemedial band, parallel to the sub-basal band, beginning at R, orange, bordered inwardly and outwardly with fuscous; a fuscous dot in anterior parr of cell beyond antemedial line; an oiange, inwardly and outwardly fuscous-bordered band on each side of discocellular, beginning at R, briefly fusing behind angle of cell, then diverging in an oval loop, converging to fuse with postmedial band near posterior margin; some specimens with an oval fuscous spot in the loop; postmedial band arising at R4, well bevond cell; orange, bordered inwardly and outwardly with fuscous, broad and erect anteriorly, narrower and somewhat bowed outwards between M2, and Cu2, weakly retracted and broadened at junction with the two medial lines; subterminal line broad, orange, diffusely bordered inwardly and, except anterior to M1, outwardly with fuscous, parallkl to outer margin, a wedge-shaped excision of inner border in cell R4; a prominent, blackish-fuscous terminal line; fringe yellowish brown, with a darker line in basal half. Hind wing ahove translucent dull yellow; an orange, fuscous-bordered discocellular bar; an orange, inwardly and outwardly fuscous-bordered postmedial band, beginning at Rs,, retracted on Cu2, nearly to angle of cell, then sinuous to anal margin; a broad subterminal band, parallel to margin, orange, diffusely bordered on both sides with fuscous; terminal line and fringe as on forewing. Wing heneath translucent dull yellow, markings of upper surface very weakly repeated on hind wing and basal half of forewing, somewhat more strongly repeated on distal half of forewing. Expanse 21 to 24 mm.