The food value of two synthetic diets for the fly larva Agria housei inverted between two temperatures, 15 °C and 30 °C. The balance of nutrients, particularly effected by the amino acid and lipid mixtures, glucose, thiamine HCl, and calcium pantothenate, was varied in the design of the two diets so that the rate of larval development axenically on one diet was superior to that on the other diet at 30 °C, but inferior to that on the other diet at 15 °C, relatively; for in any case the rate was slower at 15 °C. Differences between the rates on the diets within each given temperature were statistically significant.

Colonies of Formica obscuripes Forel and Dolichoderus taschenbergi (Mayr), two of the most common and widespread species of predacious ants in jack pine stands of the Sandilands Provincial Forest of southeastern Manitoba, were transplanted to new locations in three young jack pine plantations. When nests of the two species were alternated and spaced at intervals of 20 m, little migration occurred; a spacing of 5 m resulted in excessive movement subsequent to the transplant.

A procedure for sampling defoliating forest insect larvae by beating them from foliage, used by the Forest Insect and Disease Survey of the Canadian Forestry Service to record population trends and predict future damage and control need in British Columbia, was tested over 150,000 acres on Vancouver Island. The parameters used were average numbers of larvae per collection and percentage positive collections. Results on the test species Acleris gloverana (Wlshm.) and Melanolophia imitata (Wlk.), on host Tsuga heterophylla (Raf.) Sarg., indicated that for low (normal) population levels the present system of choosing three-tree samples along roadsides was satisfactory but that weather conditions markedly affected sample results.

A series of low-volume spray treatments were conducted to study the contact and residual effect of two concentrations of the insecticide phosphamidon to fourth instar spruce budworm, Choristoneura fumiferana (Clem.), on balsam fir, Abies balsamea (L.) Mill, and red spruce, Picea rubens Sarg. Treatment of sprayed larvae on sprayed trees, unsprayed larvae on sprayed trees, and sprayed larvae on unsprayed trees, resulted in two principal conclusions: (a) Higher concentrations of phosphamidon (1% versus 0.5% active) accelerated mortality in all instances and (b) no statistical difference (P = 0.1%) was found in the final mortalities between treatments in which only the foliage was treated and where both larvae and foliage were treated with phosphamidon.

In the phylogenetic classification of the Lepidoptera, the position of the genital opening and its modifications help to clarify the relationship of the Zeugloptera to the lepidopterous suborders. Three different systems of the suborder classification of the Lepidoptera, into Homoneura and Heteroneura (Tillyard, Imms, etc.), Monotrysia and Ditrysia (Borner), and Dacnonypha, Monotrysia, and Ditrysia (Hinton), are not supported by evidence obtained in the study of the female genitalia.The development of the female terminalia is closely associated with the mode of oviposition. Several types of female terminalia are found in the primitive Lepidoptera (Hepialidae, Neopseustidae, Tischeriidae, Lyonetiidae, Agathiphagidae, Tineidae, Nepticulidae, and Eriocraniidae). They are divided into four categories: hepialid type — the eggs are dropped randomly; typical lepidopterous type — the eggs are laid on the surface of food plants; eriocraniid type — the eggs are laid inside the food plants; tineid type — the eggs are laid in crevices of food. Each of the types is derivable from the types occurring in Neopseustidae, Tischeriidae, Agathiphagidae, and Eriocraniidae, respectively. These types are still far removed from the type of female terminalia in Micropterygidae of the Zeugloptera.The modes of egg-laying as well as the morphological characters of the female genitalia must be taken into consideration in suborder classification of the Lepidoptera.A genealogical tree based on the female terminalia suggests four main branches: hepialid branch — includes Neopseustidae and Prototheoridae; typical lepidopterous branch — includes all Ditrysia and Nepticulidae; tineid branch — includes only Tineidae; eriocraniid branch — includes Incurvariidae, Prodoxidae, Adelidae, and Heliozelidae.

Experiments were designed to determine the effects of low doses of some insecticides on the viability and physiological characteristics of commercial Bacillus thuringiensis (Berliner) as a prelude to studies on the susceptibility of lepidopterous forest defoliators to mixtures of bacteria and insecticides.

The results show that the insecticides tested had no effect on viability or physiological integrity of the bacteria.

Bacteria–insecticide combination effects varied from strongly antagonistic to strongly supplemental depending on insecticide or Thuricide® formulations and concentrations and on the relative susceptibility of the test species to either agent applied separately. Pyrethrum at 10−3 was highly potentiating to BT at 10−1 against third instar Halisidota argentata. Among Hyphantria cunea, a supplemental effect always resulted from combining Thuricide® at 10−2 with low concentrations of malathion, phosphamidon, or pyrethrum.

There was generally a drastic reduction in feeding activity among BT-treated insects and a further reduction among BT-chemical-insecticide-treated ones compared with controls.

Calling (extrusion of the sex pheromone-producing gland) by spruce budworm females follows a circadian rhythm regulated by the initiation of the photophase. At 2 °C 50% of the females call by 131/2 hr after "lights-on." Calling starts earlier at cooler temperatures. Females that have not been exposed to lights-on start calling as soon as darkness occurs. Virgin females are most attractive 3 to 4 days after emergence. Mated females call intermittently and are attractive but compete poorly with virgins. Once started, female budworm call continuously throughout the calling period, implying that their pheromone release rate is lower than if they called for short intervals only as in some other Lepidoptera. This may influence the quantities of synthetic pheromone required to disrupt mating behaviour. Calling behaviour is not influenced by the proximity of other adult budworm. At high population densities, males are apparently able to locate females before or as soon as they start to call, suggesting that communication is short range. Longer distance communication probably operates at low population densities. Population regulation by disrupting mating behaviour is therefore unlikely to succeed except at relatively low population densities.

The seasonal occurrence and larval habits of Dioryctria banksiella Mutuura, Munroe, and Ross in the western gall rust Endocronartium harknessii (J. P. Moore) Y. Hiratsuka of jack pine, Pinus banksiana Lamb., were studied in Manitoba and Saskatchewan. The early instars score the gall tissue below the bark, and the later instars mine the gall tissue and heartwood. The insect overwinters in the larval stage. The last-instar larvae pupate partly exposed and not entirely within the rust gall from June to July and adults emerge from July to August. The six species of parasites recovered from D. banksiella were Bracon lutus Provancher, Bracon sp., Microchelonus sp., Agathis binominata Muesebeck, Exeristes comstockii (Cresson), and Stiboscopus n. sp. Morphological characters used in separating the last-instar larvae and pupae of D. banksiella from those of other known species of Dioryctria are given.

The cells composing the tissue of the prismatic pigmented maculae (PPM) of the pupa of the monarch butterfly (Danaus P. plexippus) are described for the first time and their possible functions in the formation of scales and scale pigmentation in the adult butterfly are discussed.

The chorionic structure of the main body and the specialized opercular region in the egg of Zelus exsanguis (Stål) is described. The chorionic architecture of this species is typical of the ova in the Harpactorinae.

A method for weekly production in excess of 100,000 second-instar larvae of the spruce budworm, Choristoneura jumiferana (Clem.), is described. It depends on adherence to specific regimes of physical conditions and manipulation for the different immature stages. Standard, easily obtained utensils and materials are used in the rearing technique.

A 5 year study of the foliage inhabiting fauna of young apple trees which had never been treated with insecticides or miticides showed there were large numbers of species varying considerably in quantity. The study also showed that the manner in which the foliage is distributed by cluster type and the distribution of the many species on the clusters are important factors in the sampling of mixed populations of arthropods.The leaf clusters were classified into six types based on stem length and on the presence or absence of fruit. The mean number of leaves per cluster for all types combined increased until mid July but no further increase occurred after that. The variation in leaves per cluster on the longer clusters, however, continued throughout the summer even though the mean number of leaves per cluster did not.The relative abundance of each of the arthropod species, whether it was identifiable to name or not, was given a quantitative rating by using random clusters as a common sampling unit. Eleven orders, 38 families, and over 100 species were recorded. The species making up the fauna were nearly all at a low density and in general remained low during the study. All the common pests were found but only four were at a level where economic damage to the foliage resulted. Very few of the species were present in numbers sufficiently large for analysis of the factors influencing their population density or theirA list is given of those species which were sufficiently abundant to show that differences in preference for some cluster types over others is common.

The host-finding search patterns of Coeloides brunneri Viereck, a braconid parasite of Douglas-fir beetle larvae, were studied by visual observations and from tracings of the parasite’s path on a plastic cylinder wrapped around a beetle-infested log on which the parasite was searching. The female parasite locates its host, lying under approximately.6 cm of bark, through four distinct phases of host finding: random search, nonrandom search, oviposition, and nonsearch (resting and cleaning). Random search is characterized by large areas of bark being examined in a relatively straight path. Nonrandom search is a highly intensified examination of a small bark area and numerous turns of greater than 70°. Nonrandom search is initiated only at the end of a bark beetle gallery. Ovipositional probes are the culmination of successful host finding, in which the parasite paralyzes the host and deposits an egg. C. brunneri searched effectively on both Dendroctonus pseudotsugae Hopkins in Douglas-fir and D. ponderosae Hopkins in ponderosa pine, although there was a slightly more efficient search on D. pseudotsugae. The percentage of time spent in each search pattern was identical in 90-minute and 24-hour tests. A stimulus associated with the end of a larval gallery was concluded to be the key stimulus by which the parasite recognizes its host. Amputation experiments showed that the antennae are the principal receptor organs used in host finding. Various experiments and observations produced no evidence that sound or vibrations produced by the host, sound produced by the parasite (sonar), magnetism or odor of the host, or its host tree are used in host finding.

A method is described for rearing and selecting strong, robust populations of first-stage root larvae for bioassay of insecticide toxicants in soil and host plant tissue. Oviposition dishes are placed in cages with flies for a 6-hour period 3 times a week. The eggs are then incubated on silk cloth over moist blotting paper in petri dishes at 21° to 22 °C until they hatch. When the larvae move away from the empty egg cases to a food supply, they are transferred to the centre of another piece of silk cloth lying fiat on a wet sponge. The strongest of the larvae move most quickly outward from the central mass and are transferred to holding trays and later set up for bioassay with plant tissue or treated soil. The weaker larvae are discarded. In 24- to 48-hour tests with larvae obtained by this method, there was no mortality in untreated samples. When larvae were reared to maturity, mortality in untreated media averaged approximately 6% in several hundred tests conducted from 1969 to 1971.

Counting hemlock looper (Lambditm fiscellaria lugnbrosa) eggs attached to moss samples is tedious and inaccurate. Moss samples treated with a 0.5% NaOH solution for 1 minute releases the eggs, which can be washed and filtered out of the moss. Other debris can be separated through differential flotation with 15% NaCl solution. Three such washings provide data for analysis with the maximum likelihood method, producing density estimates with low-standard errors.

Based on rate of larval development, the confused flour beetle, Tribolium confusum (Duval), consistently differentiated among selected cereal cultivars provided as food. Although variations occurred in ranking order from test to test, some cultivars always permitted faster larval development than others. There was good correlation between results from tests with the beetles and from those with chicks fed the same rations. Addition of minerals and micronutrients to the cereals changed the nutritional value for the beetles but the extent of change was not uniform among the cultivars.

A chemically defined, synthetic medium that induces oviposition in the parasite Itoplectis conquisitor (Say) has been developed. The medium contains serine (0.5 M), arginine (0.05 M), leucine (0.065 M), and magnesium chloride (0.025 M); and it is more effective than host haemolymph in inducing oviposition. This completely artificial oviposition stimulant was developed to facilitate the mass rearing of the parasite on an artificial diet.

The entomogenous fungus Entomophthora erupta (Dustan), known previously only from Nova Scotia and California, is reported from Ithaca, N.Y., as an enemy of the alfalfa plant bug, Adelphocoris lineolatus (Goeze). During 1966 to 1969, the conidial stage of E. erupta was observed on A. lineolatus nymphs from late July to mid-August with percentage infection of nymphs observed to be as high as 33.3%. The possibility of colonizing this fungus in disease-free alfalfa fields to aid in suppressing populations of A. lineolatus is discussed.

A study of the ant populations was made through a transect of mid-continent North America from Churchill on Hudson Bay and various localities around the Great Lakes to Iowa and northern Illinois. Data were obtained from extensive personal collecting and from literature sources. The results were assembled and discussed within an ecological framework provided by Merriam’s life zones, and showed a regular diminution in the variety and wealth of the ant faunas progressing from south to north. Though the number of species at Churchill is extremely reduced, ants nevertheless do occur there as established reproducing colonies, even in the presumed tundra habitats. These forms which exist so far north represent a highly impoverished remnant of richer faunas further south. Although none of the species is peculiar to the area, each must be tolerant of high boreal environments. A total of 135 species and subspecies are listed for the Carolinian and Alleghenian zones combined, 43 taxa for the Canadian Zone, 4 taxa for the Hudsonian Zone, and 4 also for the Arctic Zone. Comparisons with the recorded ant faunas of the Rocky Mountains of Colorado were made with respect to the corresponding zones, namely, the Plains (Upper Sonoran), Foothills or Submontane (Transition), Montane (Canadian), Subalpine (Hudsonian), and Alpine (Arctic) zones, and appropriate similarities and differences noted.