Juvenile Monterey pines, Pinus radiata D. Don (Pinaceae), in a native stand on the Monterey Peninsula, California, exhibited wilted green shoots in the spring of 1996. The pitch canker fungus, Fusarium subglutinans (Wollenweb. & Reinking) P.E. Nelson, Toussoun & Marasas f.sp. pini, was subsequently isolated from 95% of these shoots. Spittle masses produced by Aphrophora canadensis Walley were observed on the symptomless shoots of many of these trees. The pitch canker fungus was isolated from the feeding sites of this insect on 55% of symptomless shoots, and from shoot sections adjacent to these feeding sites on 29% of the shoots. Shoots with spittlebugs feeding on them in May 1996 were more likely to develop pitch canker disease by September 1996 and March 1997 than shoots without spittlebugs. Shoots with spittle masses in March 1997 were as likely to develop pitch canker disease by May and August 1997 as shoots without spittle masses, but the origin of the infection was most likely where A. canadensis feeding had taken place. In a controlled test, the incidence of pitch canker on shoots of potted Monterey pines was dependent on the presence of a spittlebug and a spore suspension of the pathogen. Thus, both field observations and controlled studies show an association between native A. canadensis and the introduced pitch canker pathogen. The role of A. canadensis in the epidemiology of pitch canker disease remains to be determined.

Fenvalerate applied at field rates (3.4–13.7 g AI/100 L) to pear foliage in early season remained highly active to the predatory mite Typhlodromus occidentalis Nesbitt for several months until leaf drop. According to leaf disc assays, fresh deposits of fenvalerate caused considerable direct mortality but most of the later mortality was apparently caused by repellency of the residue and subsequent mite departures. Fenvalerate applied to the bark lost its contact activity more quickly than on foliage. In contrast, adult female Tetranychus urticae Koch suffered no mortality when exposed to leaf deposits, but at high dosages of fenvalerate egg laying was temporarily reduced. In slide-dip tests fenvalerate was about 5 times more toxic to T. occidentalis than to T. urticae (LC50's of 1.21 and 6.74 g AI/100 L, respectively). Our data suggest that because of the persistence of fenvalerate and the high sensitivity of T. occidentalis to this compound this predatory mite would not be able to reestablish after foliar fenvalerate applications and provide biological control of phytophagous mites.

In the laboratory, the parasitic tachinids Drino bohemica Mesn. and Bessa harveyi (Tns.) made two to four times as many attacks on tenthredinid sawfly larvae exposed on unhealthy as on those on healthy food trees. Olfactory stimuli from the unhealthy trees were preferred by the parasites to those from healthy trees. The possibility of greater masking of stimuli from hosts on healthy foliage than from those on unhealthy foliage was apparently of little importance. In the field a moderate to severe attack by sawfly larvae on a tree will cause the tree to become unhealthy and this increases its attractiveness to the parasites. Thus, the host larvae indirectly assist the parasites to find them. Stimuli that are directly influenced by the health of the food plant of the host may interact with those from other environmental factors in determining the apparent degree of preference by tachinid parasites for different hosts.

The calling posture, diel periodicity of calling, calling pattern, photoperiodic cue of calling, and endogenous circadian rhythm of calling were studied in virgin females of the bertha armyworm, Mamestra configurata Walker, at 20°C, 60% RH, and a 16 h light: 8 h dark photoperiod. The female had a definite calling posture: the ovipositor was extruded and curved downward at an angle of about 45°, the wings were raised above the abdomen in the form of a “V”, the antennae were directed posteriorly and held close to the sides of the thorax, and the abodmen was bent so that the two ends were raised slightly and the middle was lowered. Calling had a discrete diel periodicity, occurring in the last two-thirds of the scotophase. The calling pattern was characteristic of the continuous pattern of calling. The lights-off signal was the photoperiodic cue responsible for setting the timing of the diel periodicity of calling. The circadian rhythm of calling was endogenously based.

Male mullein bugs, Campylomma verbasci (Meyer), were attracted in field experiments in the Okanagan Valley of British Columbia to traps baited with females, extracts of crushed females, or Porapak Q-captured volatiles from females on common mullein, Verbascum thapsus L. Extracts from the female head and thorax attracted more males than did abdominal extracts. Traps baited with C. verbasci of both sexes caged together were not attractive. Analysis by coupled gas chromatography – mass spectrometry revealed n-butyl butyrate and n-hexyl butyrate in female extracts and captured volatiles, but only the latter compound in male extracts. However, these esters were unattractive, either alone or combined. We suggest that Porapak Q-captured volatiles could be used in pheromone isolation, and that pheromone-baited traps have promise in monitoring populations of C. verbasci.

Protopiophila litigata sp.nov. is described from Ontario and Nova Scotia. McAlpine’s (1977) key to the species of Protopiophila is modified to facilitate identification of the new species. Behaviours of P. litigata and P. latipes were studied in Algonquin Park, Ontario. Whereas P. latipes reproduces on corpses in advanced stages of decay, P. litigata mates and oviposits on discarded cervid antlers, ignoring other carrion. Unlike P. latipes, males of P. litigata engage in ’mate guarding’. These traits probably represent autapomorphies of P. litigata.

We analyzed a roll of 16 mm motion-picture film of the swarming of a cecidomyiid midge, Anarete pritchardi Kim, to calculate the acceleration of individual insects. We find that the midge moves with high accelerations, occasionally twice the acceleration of gravity, and that the midge is also subject to an inward force predominantly at the swarm edge. Energetics of midge flight is also considered by using accelerations and related data.

Pseudodiamesa arctica (Mall.), Heterotrissocladius subpilosus (Kieff.), Orthocladius (s.s.) lapponicus Goetgh., Orthocladius (s.s.) sp., Paracladius quadrinodosus Hirv., Trissocladius tricornis n. sp., and Lauterbornia sedna n. sp. develop from egg to pharate adult in Char Lake. The occurrence of the larvae of 7 additional species is apparently adventitious, All stages of the two new species plus the larvae of P. arctica and P. quadrinodosus are described. The males of T. tricornis are dimorphic and L. sedna is parthenogenetic. New distribution records are given for most of the species. The chironomid fauna of Char Lake is compared with that of other arctic lakes.

Morphometric techniques, DNA mitochondrial cytochrome c oxidase subunit 1 gene (COI) barcoding, and microsatellite flanking region sequences were used to assess the reliability of suggested morphological characters in distinguishing the green apple aphid (Aphis pomi De Geer) from the spirea aphid (Aphis spiraecola Patch), and to assess variation within these species. Both molecular approaches clearly distinguished two groups corresponding to the morphologically defined species. Differences in the length of the distal rostral segment and the number of lateral tubercles were found to be robust indicators of species membership, performing as well as multivariate approaches. Among A. pomi samples, microsatellite flanking region sequences were relatively uniform, whereas A. spiraecola exhibited much variability, which suggests that North American populations of the latter species are genetically much more complex.

Only a few studies have been made on the external morphology of both the adults and larva of a single species of sawfly, viz.: Hoplocampa balcyon (Nort.) (Bird 1926; 1927); Lygaeonematus subarcticus Forsl. (Forsslund 1936); Diprion pini (L.) (Arora 1953; 1959); Cephalcia marginata Middlekauff (Rivard 1955); and Taxonus agrorum Fallén (Ciampolini 1957). The following paper presents a detailed study of the external morphology of the larch sawfly, Pristiphora erichsonii (Htg.) and represents a consolidated revision of interim technical reports prepared earlier (Wong 1958a; 1958b). A recent paper by Bracken (1961) drew heavily from the wording and organization of the earlier of these reports for description of the external morphology of the adults of Anoplonyx luteipes (Cress.) and A. canadensis Harr. Unfortunately, Bracken incorporated minor morphological misinterpretations that have been corrected in the present paper.

Predacious mites of agricultural and horticultural importance are almost entirely of the family Phytoseiidae Berlese, 1913. These mites have received considerable attention both biologically and systematically in recent years, since the discovery that they feed on phytophagous mites of the family Tetranychidae that are of economic importance in many parts of the world.

Nesbitt (1951) revised the family in part, and present knowledge of the Phytoseiidae is largely based on his work. Garrnan (1948) devised a system of chaetotactic nomenclature that was used by both Nesbitt (loc. cit.) and Evans (1952) and is followed in this paper.

After defining the entomological use of the term mycetome a short general account is given of the various supposedly beneficial relationships between insects and internally harboured micro-organisms and the metabolic balance needed. Not all beneficial micro-organisms are harboured in mycetomes or even in mycetocytes, but the present paper is concerned only with insects having mycetomes. It is shown that there is good evidence for accepting the premise that true micro-organisms are found in insect mycetomes and that the micro-organisms supply the insect host with some useful metabolite (s), Special consideration is given to the genus Sitophilus, Here the mycetomal micro-organisms probably supply a useful nutrient that is "essential" only when the diet available to the weevils is inadequate. Whole wheat grain appears to be an adequate diet. Some strains of weevils apparently free of mycetomal micro-organisms are pale in colour, light in weight and particularly susceptible to dietary changes. Weevils reared at temperatures too much above the optimum lose their mycetomal micro-organisms. Although the organisms are pleomorphic there is evidence that their morphology in any one strain of weevil, reared under standard conditions, is constant: and thus it seems the micro-organisms may have taxonomic value in entomology. The possible origin of mycetomes and of the mutualistic associations are discussed and suggestions made about future research.

A technique for mass rearing the carrot weevil, Listronotus oregonensis (LeConte), is described. Adults were provided with carrot roots for food and oviposition sites. Larvae developed directly in these roots. Different temperature regimens for larval rearing were tested and best results were obtained using 21 °C for the first 2 weeks of larval development and 27 °C thereafter. Photoperiod was maintained at 16 h and relative humidity at 70%. Under these conditions, 97.6% of adults emerged in 39–42 days.

The process of re-emergence of Dendroctonus frontalis parent adults was investigated using emergence traps placed systematically along the bole of infested loblolly pine, Pinus taeda. Daily collections of the traps showed the re-emergence pattern by height through time. Re-emergence/100 cm2 (Y) was described as a function of time (X) by the model Y = C(18X)B−1 exp (−A(18X)B) + ɛε for intervals along the infested bole. Peak re-emergence occurred shortly after peak attack density and continued 16–20 days. Highest re-emergence density occurred at the midportion of the infested bole and tapered to the ends. The same model was used to describe re-emergence as an average process for the entire tree. For convenience in evaluating expected re-emergence totals over a time span, the cumulative form of the model was fit to the data. The proportion of re-emergence was studied using bark samples taken at the beginning and end of the process and was found to be 97% of the attacking adult population. An empirical distribution function was developed and the probability of re-emergence described using the function Y = ABCXB−1 exp (−AXB) + ɛε, where Y = the probability of re-emergence at a time X in days given that a beetle was present on day 1 of the process. The cumulative form of this model was also provided.

Using laboratory bioassays parent adults were tested and found to respond to the attractant mixture of frontalin, trans-verbenol, and loblolly pine turpentine.

Re-emergence may play several functions in the population dynamics of D. frontalis: conditioning host trees through mass colonization; establishing brood populations through multiple re-emergence, thereby efficiently allocating egg populations; identifying new hosts and aggregating populations through pheromone production; and maintenance of continuity in pheromone production at the active portion of the infestation, thereby identifying the location of trees under colonization. The prolonged re-emergence period was suggested to be of survival value to the insect in that local short term disasters would affect only a small proportion of the re-emerging population. The number of re-emergences and proportions of re-emergence were suggested to be related to oviposition per parent adult and hence attack density.

Seasonal history, adult flight activity, and damage of the obliquebanded leafroller, Choristoneura rosaceana (Harris), on filbert were studied during a 7-year period between 1976 and 1984. Data from periodic field counts and moth catches in sex-attractant traps indicated two generations per year. The first-generation adult capture peak was generally higher than the second, except in 1978 when about an equal number of moths were trapped from both generations. A physiological time scale, using degree-days (DD), was devised for predicting emergence of obliquebanded leafroller adults. The first adults from overwintering larvae emerged at approximately 374 DD above a threshold of 10 °C starting 1 March. A total of 1172 DD were required between the first and the last adult emergence during the first generation and about 519 DD during the second generation. The obliquebanded leafroller causes both foliar and nut damage in filbert orchards of Oregon. Foliar damage was insignificant, but nut damage, caused exclusively by the first-generation larvae during June and early July, was highly destructive. Larval feeding on nuts caused staining and premature drop of infested nuts resulting in substantial yield reduction in heavily infested orchards.

Two fungi, Entomophthora sphaerosperma and E. egressa, were collected and identified from larvae of the eastern hemlock looper, Lambdina f. fiscellaria (Guen.), in Newfoundland. These two fungi appear to play the most important role in the decline of looper infestations. Field trials indicate that the disease can be transmitted from laboratory-reared larvae artificially infected with the protoplast stage of E. egressa, to uninfected larvae. This suggests that infection may be established artificially within a population of the looper prior to the ’natural’ occurrence of the epizootic.

The objective of this study was to determine the quantitative and seasonal association between the pitch canker fungus, Fusarium subglutinans f. sp. pini, and two potential beetle vectors, Conophthorus radiatae Hopkins and Ernobius punctulatus Fall. In samples of reared and dissected cones, 21.4 ± 2.5% of C. radiatae and 30.1 ± 8.0% of E. punctulatus adults carried propagules of F. s. pini. Seasonal variation in mean percentage of contaminated C. radiatae and E. punctulatus emerged from cones ranged from 0 to 67% and was highest for both species February through April. In sticky traps 12.5 ± 2.3% and 11.8 ± 3.6% of E. punctulatus and Pityophthorus spp., respectively, were contaminated with propagules of F. s. pini.

Conophthorus radiatae and E. punctulatus co-occurred in 26% of the cones. The percentage of cones containing contaminated C. radiatae was greater when E. punctulatus progeny were also contaminated than when E. punctulatus was not. When contamination status of E. punctulatus was not considered, there was no significant difference in C. radiatae contamination between cones with and without E. punctulatus. Because C. radiatae appears to be a vector of the pitch canker fungus, interspecific transmission of inoculum may increase the incidence of this disease.

The parasitoid, Cephalonomia utahensis Brues (Hymenoptera: Bethylidae), was frequently observed parasitizing late-instar larvae of E. punctulatus, but was not found on larvae of C. radiatae. Emergence of large numbers of C. utahensis represents another potential source of inoculum for transmission to prey species.

In the laboratory, it has been found that females of R. pomonella (Walsh) mating frequently throughout their lives laid about twice as many fertile eggs as females allowed to mate only a few times during their first two weeks after emergence. However, mating had little effect on the total numbers of eggs laid. Females mating frequently averaged 395 eggs and 95% were fertile whereas those mating only a few times averaged 360 eggs and 46% were fertile.

Disruption of mating for control of Oriental fruit moth [Grapholita molesta (Busck) (Lepidoptera: Tortricidae)] using Isomate M pheromone dispensers was tested from 1987 to 1990 in the Niagara Peninsula of Ontario. The effectiveness of pheromone was evaluated using virgin female-baited traps, synthetic pheromone-baited traps, and by inspecting samples of twigs and fruit for evidence of G. molesta damage. No males were caught in virgin female-baited traps placed in pheromone-treated plots. Synthetic pheromone-baited trap catches of male moths were reduced by 85–100%. Pheromone provided commercially acceptable control over two consecutive growing seasons at a commercial farm with a relatively low density G. molesta population. Pheromone did not provide commercially acceptable control at an experimental farm with a relatively high density G. molesta population. The incidence of capture of males in virgin female-baited traps, in synthetic pheromone-baited traps, and the incidence of damage to peach twigs by first- and second-generation G. molesta larvae could not be used to predict the incidence of damage to fruit at harvest. The results suggest that pheromone-mediated mating disruption may have potential as a method for controlling the Oriental fruit moth in orchards with relatively low density populations.

In an investigation of Camelina sativa (Linnaeus) Crantz (Brassicaceae) and five common insect pests of canola (Brassica napus Linnaeus) (Brassicaceae), little feeding damage to the plant was inflicted by crucifer-feeding specialist flea beetles (Phyllotreta Chevrolat species) (Coleoptera: Chrysomelidae), Delia Robineau-Desvoidy (Diptera: Anthomyiidae) root maggots, or diamondback moth (Plutella xylostella Linnaeus (Lepidoptera: Plutellidae)). In choice tests, diamondback moths laid fewer eggs on C. sativa than on B. napus leaves. Diamondback moth larvae consumed less C. sativa leaf tissue, and tended to have a longer developmental period on C. sativa. Larvae of the polyphagous bertha armyworm (Mamestra configurata Walker (Lepidoptera: Noctuidae)) had similar feeding levels on C. sativa and B. napus plants. However, there was a longer developmental period from larval to pupal stage and pupae weighed less when fed on C. sativa foliage, suggesting that C. sativa contains antibiosis factors against bertha armyworm. Two strains of aster yellows phytoplasma, 16SrI-A and 16SrI-B, were identified in C. sativa and in Macrosteles quadrilineatus (Forbes) (Hemiptera: Cicadellidae). Differences in incidence of aster yellows and abundance of M. quadrilineatus were observed among lines of C. sativa. The findings confirm that C. sativa is unlikely to support high populations of these insect pests on the Canadian prairies.