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.

Five controlled-release granular formulations were developed that eluted 3-methyl-2-cyclohexen-1-one (MCH) in the laboratory at a rate ≥ 0.5µg/h for 60 days. Elution rate was determined by trapping gaseous radioactive MCH followed by scintillation counting. The inert components of these formulations consisted either of a wax-coated molecular sieve, polyethylene emulsion-coated ground corncob, or dimer acid polyamide beads. These formulations and a liquid standard were applied 9 May just prior to Douglas-fir beetle (Dendroctonus pseudotsugae Hopk.) flight to plots containing single, freshly felled Douglas-fir (Pseudotsuga menziesii var. glauca) trees. Three months later, infestation by Douglas-fir beetle and other insects was evaluated. All treatments except coated corncobs and certain applications of the molecular sieve significantly reduced Douglas-fir beetle attacks. Douglas-fir beetle brood in three treatments was significantly less than in controls. Abundance of entomophagous insects was proportional to density of host beetle attacks. Douglas-fir beetle attack density was negatively correlated with degree of infestation by the scolytid Pseudohylesinus nebulosus (Lee).

Orthops rubricatus (Fallén), a European species now known to occur in North America, is transferred to the genus Pinalitus Kelton. Pinalitus solivagus (Van Duzee) is reported from British Columbia, and P. utahensis Knight and P. brevirostris Knight are considered to be synonyms of it. Pinalitus rostratus n. sp. is described from Canada and western United States. Pinalitus californicus Knight is transferred to the genus Proba Distant. A key to species is provided.

Determination of the spatial pattern and estimation of the density of egg, larval, and adult populations of Ctenicera destructor (Brown) and Hypolithus bicolor Eschscholtz were made by soil sampling, and for C. destructor adults, also by cages that collected the emerging adults in the spring. Eggs of both the above species and also those of Aeolus mellillus (Say), which were also found in the samples, were highly aggregated. Small C. destructor larvae were most highly aggregated and medium larvae less so; large larvae were usually randomly distributed. Unlike C. destructor, large H. bicolor larvae were more highly aggregated than either the small or medium bicolor larvae. Sampling by emergence cages showed that C. destructor adults were aggregated while sampling by soil cores showed them to be randomly distributed. The different result obtained by the two methods was attributed to the difference in the size of the sampling unit. Aggregation was detected in 29% of the H. bicolor adult population sampled by soil cores only.

Larval densities of C. destructor ranged from a low of 0.25 to a high of 1.46 per sample unit (81 cm2) over the 14-year period that samples were taken; densities of H. bicolor ranged from 0.16 to 0.64. Densities of C. destructor and H. bicolor adults averaged about 6 (range 1–16) % and 12 (0–27) % of the total population of larvae and adults for each respective species. Population composition, in terms of adults and larvae of different sizes, and population fluctuations are discussed.

The relation between density and the number of sampling units required to achieve four levels of margin of error at four levels of statistical significance was determined.

No satisfactory transformation was found for data of individual samples with a mean less than 1. Several common transformations, including Taylor’s power transformation, were satisfactory for stabilizing the variance of pooled samples.

Methods for sampling eggs, larvae, and pupae of Aedes spp. in a temporary pond are described. Changes in the area of the pond were mapped by reference to 8 transect lines and correlated with depth at the centre. These pond outlines at different centre depths were also used for the characterization of sampling strata. Samples were taken along the 8 transects only. Soil cores were taken from the dry pond bed, and the larvae that hatched after repeated floodings in the laboratory were used as estimates of the number of viable eggs present in the cores. The temperature of the water used for flooding was adjusted to hatch the ’spring’ species separately from Aedes vexans and Aedes cinereus. Samples were taken in the spring of 1974, in the autumn after the pond had been naturally reflooded, and in the spring of 1975. The estimated number of eggs in the pond decreased with time and the number estimated to have hatched in the summer of 1974 was similar to the estimated number of larvae. The standard errors were about 10% of the mean. Larvae and pupae were sampled with a Belleville sampler and population estimates were obtained for Aedes vexans and Aedes cinereus in August 1974 and for the ’spring’ species, Aedes euedes and Aedes mercurator, in April–May 1975. The efficiency of this program increased when the sample size exceeded 40, when the size of the sample unit was appropriate to the density of larvae, and when sufficient time was allowed for larvae (1 h for instar I) to become trapped. However, standard errors of less than 10% of the mean were obtained only at high mosquito densities.

Experiments were done in an attempt to ascertain the significance of the mandibular glands of nurse bees in female caste differentiation. Groups of 30 or 75, 10-day-old nurse bees, with their mandibular glands removed, were caged in the laboratory. Each group was provided with female larvae in plastic queen cell cups. The treated nurse bees were able to rear a few pupae, from these larvae, which were classified as queenlike intermediates while the untreated nurse bees reared pupae or adults which were classified as queens or queenlike intermediates.

A population of the Douglas-fir cone moth, Barbara colfaxiana (Kft.), was studied on the Buckhead Seed Production Area, Lowell Ranger District, Willamette National Forest, Oregon, during 1971. Factors contributing to the mortality of B. colfaxiana are presented in a partial life table and discussed. The egg – instar I was identified as the critical age interval and resinosis the critical factor.

Experiments were designed to determine the actual number of spores and crystals of Bacillus thuringiensis (B.t.) and of nuclear polyhedral virus and entomopoxvirus deposited at ground level per unit area and to determine any change in spore:crystal ration following aerial application in forested plots.

The results indicate that: (1) The estimation of B.t. aerial spray deposits by the commonly used agar plate method grossly underestimates the deposit rates of active ingredient. The tracer dye method more accurately estimates deposit rates for both B.t. and entomopathogenic viruses. As a dye 0.1% Erio Acid Red XB is recommended. (2) The relationship between drop size and the number of spores and crystals or virus inclusion bodies/drop is curvilinear. This relationship probably holds true regardless of spray volume rate. All visible spray deposits at ground level contained some active ingredient. (3) With B.t. sprays the sporexrystal ratio emitted from the aircraft is not changed upon target impact.

The detection of insect infestation by the Canadian Grain Commission is decreased in efficiency by the mortality of adult beetles in the pneumatic sample delivery systems used in terminal elevators in the Vancouver, B.C., area. Dead insects are difficult to see while grading the grain and cannot be extracted by Berlese funnels.

The level of mortality varied with the species of beetle and the system tested, but not with the type of grain. In one system the following mortalities were found: Cryptolestes ferrugineus (Stephens), 73%; Oryzaephilus surinamensis (L.), 65%; Tribolium castaneum (Herbst), 65%; and Sitophilus granarius (L.), 22%. C. ferrugineus, the most important insect infesting Canadian grain, sustained an average mortality of 55% in the five systems tested. No consistent mortality pattern was found among the systems with respect to delivery tube length, number of turns, or approximate grain speed. Berlese funnel extraction was found to be inefficient for O. surinamensis and inconsistent for S. granarius.

The populations of Laspeyresia pomonella (L.) on two cultivars in an insecticide free orchard showed similar trends over a 12-year period. Infestation of fruit was greater on the cultivar with the larger annual crop. Predation of eggs on the cultivar Delicious was greater than on the cultivar McIntosh. Mortality of neonate larvae was greater on McIntosh. Egg-to-egg survival ratios varied from 0.23 to 6.83. The average generation survival of egg to adult for the 12-year period was near 10% which confirms an earlier value established empirically.

Within-tree models of Dendroctonus frontalis generation survival from attacking adults to emerging adults and survivorship from eggs to emergence were developed for five regions of the infested tree bole of Pinus taeda L. The generation survival model (GS) describes the number of D. frontalis/attacking adult as a function of time at a specific height. The form of the model is

YGS = 1.0 + C(1–e–20.0X)eA(1.0–X)B + ɛ.

The survival model (S) describes the number of D. frontalis/100 eggs as a function of time at a specific height. The form of this model is

YS = CeA(1.0–X)B + ɛ.

The generation survival model indicated that the rate of survival was primarily a function of generation development time, rather than position on the infested tree bole. The rates also varied in different sections of the tree depending on the initial egg/attacking adult population of D. frontalis. The emergence/attack ratios for the tree sections were slightly greater at the top and bottom than in the middle of the infested bole.

The survivorship curves, based on an initial cohort of 100 eggs, were similar for the various sections of the tree bole. Again, the rate of population change was primarily a function of developmental time, rather than position on the tree. The curves for the various tree sections were essentially the same.

The combined action of the various biotic and abiotic mortality agents acting in the different sections of the tree resulted in essentially uniform survivorship throughout the infested portion of the tree bole.

Ethanol and sulcatol (6-methyl-5-hepten-2-ol), primary attractant and population aggregation pheromone, respectively, for Gnathotrichus sulcatus, were deployed alone or in combination on stumps and felled trees in the University of British Columbia Research Forest, Maple Ridge, B.C. On 18 April 1974, four Douglas-fir trees were felled at each of three locations, and four western hemlock trees were felled at each of three other locations. Felled trees and their respective stumps were baited on 26 April. Attacks by G. sulcatus and bark beetles were recorded at weekly intervals until 25 October. G. sulcatus attacks increased rapidly, reaching a maximum in June and July, followed by a steady decrease to October. Attacks by Dendroctonus pseudotsugae, Pseudohylesinus nebulosus, and P. tsugae showed characteristic seasonal trends, but were not correlated to any of the treatments. Over half the G. sulcatus attacks were on stumps, in which attack densities reached 683.5/m2. The greatest numbers of attacks were on stumps and logs baited with sulcatol or sulcatol plus ethanol. There was a significant interaction between sulcatol and ethanol on Douglas-fir but not on western hemlock. Significantly more G. sulcatus attacked ethanol-baited western hemlock stumps and logs than unbaited controls. However, there was no difference between the level of attack on ethanol-baited Douglas-fir and the controls. The role of ethanol is hypothesized to be more of a boring stimulant than a major attractant. Stumps baited with sulcatol and then treated with ethanolic solutions of systemic insecticide could be used to trap and kill field populations, thus reducing numbers of G. sulcatus being transported to log-booming grounds, dryland sorting areas, and sawmills.

Larvae of bertha armyworm, Mamestra configurata Walk., collected in 1972–75 on rapeseed in the prairie provinces of Canada (predominantly in Manitoba), were killed by one virus, one fungus, one microsporidium, seven insect parasites, and by other factors. Mortality from disease was about 24% in 1972 when bertha armyworm was abundant, but much lower in succeeding years after the host’s population density declined. The most important hymenopterous parasite, Banchus fiavescens Cress., was relatively rare in 1972 but subsequently killed over 40% of the host larvae each year. A tachinid, Athrycia cinerea (Coq.), killed over 20% of the mature bertha armyworms in each generation. Each of the other five parasite species was associated infrequently with M. configurata. Details of the biology of each pathogen and parasite are presented. About 12% of the mature host larvae died because they failed to empty the gut, with subsequent penetration of the gut wall by bacteria, or because they did not form a morphologically-sound pupa. Pupae of M. configurata died in the soil following penetration of the gut wall by bacteria, as a result of soil cultivation, and from low temperatures in winter. No pathogens or parasites were recorded in field-collected pupae, though an ichneumonid, Ichneumon canadensis Cress., parasitized pupae in a field cage and may occasionally do so in natural conditions. No pathogens or parasites of bertha armyworm eggs were recorded. A preliminary survival model for bertha armyworm, based on estimates of mortality from various causes identified in this study, is presented. The possibility of preventing or reducing future oubreaks of M. configurata by colonizing additional parasite or pathogen species in the prairie provinces is discussed.

Population data collected from 132 trees during a 3-year period were used to simulate spots of K trees (1≤ k ≤ 50) infested by the attacking adult stage of Dendroctonus frontalis Zimmerman. The total number of beetles on the K trees was then estimated by sampling k trees (1≤ k ≤ 10). The k trees were chosen at random and by selecting those of largest diameter and largest infested area. Within-tree populations were estimated at two levels of precision and within-spot populations were then estimated by scaling the sum of the k within-tree estimates according to the proportion of the tree numbers, tree diameters, or infested phloem areas included in the sample. The various combinations of tree selection, within-tree precision, and scaling produced 10 procedures which were evaluated for bias, precision, and cost as estimators of within-spot populations. Bias was calculated as the mean of the proportional errors in estimating the true numbers, and the standard deviation of the proportional errors was used as a measure of precision.

The procedures in which trees were randomly selected provided unbiased estimates of the within-spot populations. Selecting the largest trees tended to overestimate the true number with the bias diminishing to zero as k → K. However, separate analyses of trees sampled on the same date within actual spots showed no reason to reject the hypothesis of no difference in beetle density (insects/diameter and insects/area) between the largest and smallest trees.

When k = K = 1, the precision of all within-spot estimators was equivalent to the precision of the within-tree estimate. For larger k = K, the precision improved approximately as √(K). No attempt was made to derive functional relationships of precision for k < K. For each procedure, precision improved as k → K. Sampling the k trees at two sample heights (3.5 and 6.5 m, 4–100 cm2 disks/height) was more precise than single level sampling (4 disks at 5 m), but equally precise estimates could be obtained by single level sampling of just one or two additional trees in the spot. Random selection of the k trees with scaling by the number of infested trees was the least precise of the estimating procedures; scaling by diameter and by infested surface area increased the precision. Best precision was obtained by selecting the k trees of greatest infested phloem area, but selecting the largest diameter trees was nearly as precise. The least costly procedure for obtaining a desired level of precision consists of selecting the k trees of largest diameter and extracting 4 disks/tree at 5 m.

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.

New synonymies and new combinations affecting North American Pityophthorus are proposed as follows: Pityophthorus Eichhoff (= Myeloborus Blackman and Ctenyophthorus Schedl) n. syn.; Araptus obsoletus (Blandford) n. comb.; A. poricollis (Blandford) n. comb.; Gnatholeptus epistomalis (Schedl) n. comb.; G. semiermis (Nunberg) n. comb.; G. shannoni (Blackman) n. comb. (= Pityophthorus gentilis Schedl); G. subscribratus (Schedl) n. comb. (= Pityophthorus zeteki Blackman); Pityophthorus absonus Blackman (= demissus Blackman and inyoensis Bright); P. blandus Blackman (= singularis Bright); P. carinulatus Swaine (= aquilus Blackman, caelator Blackman and opimus Blackman); P. comosus Blackman (=foratus Wood); P. digestus Le Conte (= idoneus Blackman, hopkinsi Blackman and ponderosae Blackman); P. diglyphus Blandford (= leiophyllae Blackman and auctor Blackman); P. guatemalensis Blandford (= quercinus Wood); P. infulatus Blackman (= mollis Blackman and hubbardi Blackman); P. intextus Swaine (= shepardi Blackman, cascoensis Blackman, tonsus Blackman, kenti Blackman, and pilifer Schedl); P. nitidus Swaine (= borealis Swaine, anceps Blackman, alpinensis Hopping and aquilonius Bright); P. nocturnus Schedl (= hidalgoensis Blackman); P. opaculus Le Conte (= abietis Blackman, albertensis Blackman and exiguus Blackman); P. rhois Swaine (= natalis Blackman); P. solus Blackman (= cribratus Blackman); P. toralis Wood (= collinus Bright); P. venustus Blackman (= artifex Blackman); P. virilis Blackman (= fortis Blackman). New species are: P. aciculatus (Guatemala, Mexico), apachae (Arizona), aztecus (Mexico), blackmani (Mexico), chiapensis (Mexico), clivus (Mexico), cortezi (Mexico), culminicolae (Mexico), declivisetosus (Mexico), lecontei (Arizona, New Mexico), lepidus (Mexico), montivagus (Mexico), mormon (Utah), separatus (South Carolina), sulcatus (Arizona), viminalis (Mexico), and woodi (New Mexico).

The genus Syndyas Loew is revised for North America, and four of the six included species are described as new. A general description of the Nearctic species group is given, and keys are presented. All species but one are restricted to eastern North America. Three unplaced specimens that may represent additional species are discussed.

An experimental component analysis approach is used to define the physiological interactions of carbohydrate nutrition and the manner in which it regulates the crop-emptying rate. The basic components of the crop-emptying rate are frequency of valve opening and the volume of the slug of fluid which passes through the valve. This volume is solely a function of crop volume, but the frequency of opening is a complex function determined by the crop volume, and by gut activity and blood osmotic pressure, both of which are related to nutritional parameters. To guide the formulation of the relationship, a model of the mechanism of valve function is proposed, based in the phenomenon of muscle creep.

The osmotic pressure is estimated by calculating the change in blood trehalose level estimated from observed rates of disappearance of sugar from the crop. Sugar emptying from the crop diffuses from the midgut to the blood, where it is partitioned between trehalose and glycogen according to established biochemical relationships. The model developed fits a wide variety of published data on crop-emptying rates of flies fed different volumes and concentrations of sugar, and may be applied to active, inactive, and flying insects.

Larvae of three Nearctic species of Axonopsinae, Axonopsis setonensis Habeeb, Brachypoda cornipes Habeeb, and Woolastookia sp. near pilositarsa (Habeeb) are described, and diagnoses are proposed for the taxa involved. Observations on these larvae permit new insight regarding the phylogenetic affinities of Axonopsinae, thereby leading to a suggestion for reassessment of the supergeneric classification of the Aturidae.

Ecitovagus gibbus, new genus and new species of diapriid wasps (Diapriinae, Diapriini) associated with the army ant Neivamyrmex nigrescens (Cresson) in Arizona, is described. Taxonomic and ecological relationships with other ecitophilous diapriids are discussed.