Ten galls and pseudogalls caused by poplar gall aphids are described, their development discussed, and a key to their identification presented. Nine of these malformations are from Quebec poplars and one from Crystal Springs on Pigeon Lake, Alberta. All of the aphids involved belong to the family Eriosomatidae and sub-family Pemphiginae. Seven species are members of the genus Pemphigus Hartig, and of these P. bursarius (L.) and P. populitransversus Riley are well recognized economic vegetable pests in the United States. A monoecious species P. spirothecae Passerini is reported for the first time in North America. P. monophagus Maxson was collected from balsam poplars in Alberta. Other genera represented are Thecabius Koch (two species) and Asiphum Koch (one species).

The larvae of Tetralopha web leaves of many kinds of trees and shrubs. A key to nine North American species is included, with descriptions of the last instar larvae. The species considered are Tetralopha robustella Zeller, T. militella Zeller, T. expandens Walker, T. aplastella Hulst, T. asperatella Clemens, T. vacciniivora Munroe, T. euphemella Hulst, T. scortealis Lederer, and T. baptisiella Fernald.

The absence of males in 1000 adults examined over a 2 year period, the facility with which unmated females deposited eggs, and the high percentage (86%) of these eggs which hatched are presented as evidence for obligatory parthenogenesis in Cloeon triangulifer McDunnough. It is suggested that the unusually long (June to November) emergence period of the species is a result of parthenogenesis.

A ninhydrin-positive substance analysis of fourth instar larval hemolymph of the eastern hemlock looper, Lambdina fiscellaria fiscellaria (Guenée), was conducted. Two separate larval populations were reared on a defined diet during the early stages and later on fresh, young balsam fir foliage. The results indicated the presence of at least 38 compounds. L-glutamine and(or) L-asparagine, L-histidine, and L-lysine occurred at high concentrations (> 5000 nM/ml). Ammonia, L-arginine, L-threonine, L-serine, L-glutamic acid, glycine, L-alanine, L-valine, L-isoleucine, L-leucine, L-tyrosine, and L-phenylalanine occurred at intermediate levels (1000–5000 nM/ml). The current report of the presence of L-1-methylhistidine and L-3-methylhistidine is the second report of any methylated derivative of histidine in insect hemolymph. The results of the analytical study were used to modify the composition of Grace’s insect tissue culture medium which had previously been found to support growth of protoplasts of the looper pathogen Entomophthora egressa MacLeod and Tyrrell. Fungal growth indicated a shorter generation time (4.7 h) on the medium modified to more closely approximate the looper hemolymph as compared with the generation time (6.2 h) on Grace’s medium.

A total of 14 known fatty acids and one unknown fatty acid were detected in the third instar, fourth instar, prepupa, and female and male pupae of the eastern hemlock looper, Lambdina fiscellaria fiscellaria. The C8:0,3 C10:0, C22:1, and C24:0 fatty acids and an unknown fatty acid were not detected in the third instar larvae, and the unknown was also absent from the fourth instar larvae. The C24:0 fatty acid was absent from the prepupae and both the male and female pupae. The C22:1 fatty acid was absent from the prepupae. Otherwise, developmental stages contained the C8:0, C10:0, C14:0, C15:0, C16:0, C18:0, C18:1, C18:2, C18:3,C20:0, C20:1, C22:0, C22:1, and the C24:0 fatty acids and the unknown fatty acid. In general, the level of a given fatty acid decreased with succeeding developmental stages. The lipid level was also determined for each developmental stage.

Intensive and systematic laboratory studies conducted under various experimental conditions (larval stage, physiological condition of the insect, temperature, formulation) revealed that non-crystalliferous strains of Bacillus thuringiensis Berliner and B. cereus Frankland and Frankland were equally pathogenic for larvae of Choristoneura fumiferana Clemens as the crystalliferous strain of B. thuringiensis tested. Also the addition of minute quantities of chitinase (10,000 UN/ha) considerably increased the efficiency of commercial preparation of B. thuringiensis against C. fumiferana.

At 20°C, B. thuringiensis var. kurstaki provoked a slow septicemia in 3rd instar larvae of C. fumiferana which resulted in 90% larval mortality in 27 days. Under the same experimental conditions, a non-crystalliferous strain of B. thuringiensis (No. 17) and two strains of B. cereus, entomopathogens isolated from C. fumiferana and from a Tachinidae, also caused a slow septicemia resulting in 90% mortality of 3rd instar larvae after 30 to 32 days.

Experiments revealed that the symptoms of infection (lethargy, loss of weight) caused by B. thuringiensis + chitinase were far more rapid and pronounced than those provoked by B. thuringiensis alone The commercial preparation 26B prepared by Sandoz-Wander, applied at a rate of 16.8 × 109 BIU/ha caused only 80% mortality of 3rd and 4th stage larvae, while the complex Sandoz + chitinase N.B.C. provoked 100% larval mortality between 9 and 27 days depending upon the experimental conditions used Similar results were obtained with Dipel 36B. For instance, at 20°C Dipel + chitinase N.B.C. provoked 100% mortality of 3rd stage larvae in 9 days, while with Dipel alone, the same level of mortality was reached after 24 days. Also, it was established that C. fumiferana larvae reared on Abies balsamea were far more susceptible to the action of the bacillus than those reared on artificial diet.

These results confirmed that addition of chitinase considerably increased the pathogenic properties of B. thuringiensis on C. fumiferana and the low efficiency of the bacillus alone. The addition of chitinase to commercial B. thuringiensis preparations is required and of prime importance in future use of B. thuringiensis for the control of this insect pest.

Parasitoids of the overwintering generation of the introduced pine sawfly were surveyed in Minnesota. The parasitization rate was greatest in cocoons collected from foliage in fall 1971, but there was nearly complete mortality of sawflies and parasitoids in cocoons above the snowline by April 1972. Monodontomerus dentipes (Dalm.) most commonly emerged from cocoons collected from trees and shrubs in fall 1971. Exenterus amictorius (Panz.) was the most common parasitoid of cocoons collected from duff in both 1971 and 1972.

Euxoa auxiliaris (Grote) females yielded the largest amount of extractable pheromone after they were stored at least 44 days at 10 °C and then 7 days at room temperature. The males would not respond to the pheromone until they were 28 to 37 days of age and their clearest responses were between 2 and 4 h of the dark cycle. Agrotis orthogonia Morrison females produced pheromone within 1 day after emergence and 2-day-old males responded to it between 5 and 7.5 h of the dark cycle when the olfactometer background light intensity was 0.35 lux. Female Euxoa tristicula Morrison produced pheromone 3 days after emergence and the males responded between 3 to 5 h of the dark cycle.

Catches of male clover cutworm moths with Z-11-hexadecen-1-yl acetate containing 10.8 to 25.0% Z-11-hexadecen-1-ol decreased linearly as the percentage of alcohol increased. The largest catches were with the acetate containing 10.8% alcohol, and at a concentration of 5 mg/rubber carrier. This bait was effective in the field for at least 4 weeks Catches of moths with the attractant on polyethylene carriers were independent of the attractant concentrations, and were significantly less (P < 0.01) than with the same attractant concentrations on rubber carriers.

Linsleya sphaericollis (Say) adults have been seen in various parts of Manitoba, Saskatchewan, and Alberta from mid-June to mid-August, and will feed on western snowberry, Symphoricarpos occidentalis Hooker, species of wild and cultivated honeysuckle, Lonicera spp., common lilac, Syringia vulgaris L., and green ash, Fraxinus pennsylvanica Marsh. Field-collected adults lived for up to 8 weeks in captivity and laid on the average nearly one batch of eggs per female, with each batch containing an average of 50–51 eggs. The eggs were killed if exposed to temperatures of 0–10°C for 3 weeks, but endured these temperatures for a week. Embryonic development was slow, hatching was unusually irregular, and the best hatching temperature was 25°C. The incubation period was about 50% longer at 20°C, and hatching was inhibited at 15° and 30°C. The first instar larvae lived for up to 7 weeks without food. Some of the larvae fed on the eggs of Melanoplus sanguinipes (Fabricius) and M. bivittatus (Say), but the response was poor; they did not feed on ant larvae and pupae, or on the larvae of wheat stem sawfly (Cephus cinctus Norton). The data indicate that there are five vorant larval instars, that the typical meloid hypnothecal and non-vorant larval instars are omitted, that this insect overwinters as a fifth instar larva, that the natural food of the larvae is grasshopper eggs, and that the genus Linsleya should be included in the subtribe Epicautina.

Larvae of Pityokteines elegans Swaine and Scolytus ventralis LeConte are distinguished by differences in coronal suture, frontal suture, antennae, and labium. Anatomical features are illustrated by SEM micrographs.

The European species Perizoma alchemillata (L.), first collected in Newfoundland 22 July 1954, is now widely distributed throughout the island. Notes on its distribution, life-history, and ecology are provided. The adult moths and the male and female genitalia are illustrated to facilitate identification.

Sexual behavior in the two species of Cysteodemus LeConte consists of: (1) a simple form of courtship that lacks an elaborate tactual display, (2) a prolonged mating period during which the male remains mounted on the female, (3) high levels of female receptivity regardless of previous mating, and (4) postcopulatory behavior. This behavior represents a condition intermediate between that found in the Meloinae and Nemognathinae, the two major subfamilies of blister beetles.

Studies of the biology of carabids have been limited by the difficulty of sexing living individuals. Mitchell (1963) described the dissection of adults of two carabid species and stated that the aedeagus of the adult male is visible at all stages of maturity.

Descriptions and figures of five undescribed species are presented: Lachlania talea, L. iops, Epeorus (Iron) packeri, Rhithrogena notialis, and Heptagenia bella. Heptagenia mexicana Ulmer is tentatively transferred to the genus Stenonema, the nymphal stage is described for Isonychia sicca manca Eaton and Homoeoneuria salviniae Eaton, and new collection records extend the known distributional range of Dactylobaetis mexicanus Traver & Edmunds, D. musseri Traver & Edmunds, D. zenobia Traver & Edmunds, Isonychia sicca manca, Homoeoneuria salviniae, Epeorus (Iron) metlacensis Traver, and Stenonema mexicana.

Of the three large ephydrid flies of Yellowstone’s thermal springs, Ephydra thermophila numerically dominates acidic springs because only it can tolerate their water. Alkaline spring effluents are shared by Ephydra bruesi and Paracoenia turbida. E. bruesi is excluded from alkaline high productivity springs, probably because its larval maturation time is long, relative to the short life of patches of larval habitat. Consequently, such springs support only P. turbida. Proportions of the two species in alkaline low-productivity springs are apparently determined by the proportions of available larval food occurring in still versus flowing water. P. turbida is superior in still water, and E. bruesi wins in flowing water. The analysis leads to predictions (i) that E. bruesi should be relatively abundant in low-productivity springs with pulsating flows, and (ii) that E. bruesi adults should prefer ovipositing in low-productivity effluents, while P. turbida adults should be less particular.

The predator fauna of alfalfa, Medicago sativa L., was studied at Ithaca, N.Y., during 1966–69. Predators are separated into species that completed their life cycle on alfalfa (primary), species whose adults took prey from the plants but bred elsewhere (secondary), and species not observed to capture prey on alfalfa (incidental). Seasonal occurrences and prey records are given for the 19 primary species and the secondary species whose prey were identified.

The known species of the Indo-Australian genus Heortia are reviewed. The genus and its species are characterized; its distribution and relationships are discussed; the species are keyed and figured and their genitalia are described. H. iridia n. sp., from Celebes [Sulawesi], and H. dominalis restricta n. subsp., from New Britain and Rooke Island, are described.

Field tests were made of the fungal inoculation method of Reid et al. which assesses the potential of individual lodgepole pine trees (Pinus contorta Dougl var. latifolia Engelm.) to resist attacks by mountain pine beetle (Dendroctonus ponderosae Hopk.). Four hundred and eighty-four trees were inoculated with one of the beetle’s mutualistic blue-staining fungi (Europhium clavigerum Robinson and Davidson), tree responses were determined, and the potential of each tree to resist D. ponderosae was predicted. Two months later, after mountain pine beetles had attacked some of these same trees, most of the predictions based on the fungal assay system proved to be incorrect. Most of the trees which were attacked and which had been rated potentially resistant did not prevent successful bark beetle reproduction. These results, contrary to those of Shrimpton and Reid, suggest that some improvement is needed in the fungal assay method of assessing resistance of lodgepole pine to mountain pine beetle. Measures of tree resistance based on success of mountain pine beetle reproduction showed no difference in the proportion of non-resistant trees between epidemic and endemic areas.

Keys, descriptions, and illustrations are presented for the identification of the larvae, pupae, and adults of the four species of black flies known from Iceland, viz. Prosimulium (Prosimulium) ursinum, Simulium (Psilozia) vittatum, S. (Eusimulium) aureum, and S. (E.) vernum. Maps depicting their distributions within that country, and brief biological notes are given.