Showing papers in "Canadian Entomologist in 1975"
TL;DR: It is concluded that most failures were caused by inadequate procedures, rather than by any weaknesses inherent in the method, that those inadequacies can be avoided in the future, and therefore that biological control of pest insects has much unrealized potential for use in Canada.
Abstract: This is an analysis of the attempts to colonize at least 208 species of parasites and predators on about 75 species of pest insects in the field in Canada. There was colonization by about 10% of the species that were introduced in totals of under 5,000 individuals, 40% of those introduced in totals of between 5,000 and 31,200, and 78% of those introduced in totals of over 31,200. Indications exist that initial colonizations may be favoured by large releases and by selection of release sites that are semi-isolated and not ecologically complex but that colonizations are hindered when the target species differs taxonomically from the species from which introduced agents originated and when the release site lacks factors needed for introduced agents to survive or when it is subject to potentially-avoidable physical disruptions. There was no evidence that the probability of colonization was increased when the numbers of individuals released were increased by laboratory propagation. About 10% of the attempts were successful from the economic viewpoint. Successes may be overestimated if the influence of causes of coincidental, actual, or supposed changes in pest abundance are overlooked. Most of the successes were by two or more kinds of agents of which at least one attacked species additional to the target pests. Unplanned consequences of colonization have not been sufficiently harmful to warrant precautions to the extent advocated by Turnbull and Chant but are sufficiently potentially dangerous to warrant the restriction of all colonization attempts to biological control experts. It is concluded that most failures were caused by inadequate procedures, rather than by any weaknesses inherent in the method, that those inadequacies can be avoided in the future, and therefore that biological control of pest insects has much unrealized potential for use in Canada.
121 citations
TL;DR: In this article, the Ctenicera destructor (Brown) larvae responded to CO2 gradients between glass plates, that ascended on the average by 0.002% (soil) and 0.005% (agar)/cm over a distance of from 12 to 16 cm.
Abstract: Several species of wireworms were attracted to germinating wheat, air from flasks of germinating wheat, decomposing oatmeal, commercial CO2 and, in addition, germinating seeds of eight other cultivated plant species. Larvae located a biological or experimental source of CO2 by a directed movement along CO2 gradients, from distances up to 20 cm.Methods and apparatus for measuring small CO2 gradients, using gas chromatography and mass spectrometry, are described. Ctenicera destructor (Brown) larvae apparently responded to CO2 gradients between glass plates, that ascended on the average by 0.002% (soil) and 0.005% (agar)/cm over a distance of from 12 to 16 cm. The "sensitivity threshold" was calculated as being 1–2 ppm over the distance involved in one deflection of the head during klinotactic orientation. Attractancy was observed within a range of CO2 concentration from about 0.036% to 1.5%. Repellent effects did not appear to be only related to concentration, but possibly were due to steepness of the gradient and(or) previous exposure to CO2.Passing an air stream from germinating grain over a KOH solution eliminated the attractancy of the grain by removing the CO2 and possibly other undetected attractants. A small percentage of C. destructor larvae apparently oriented to an ethylene source, but it was concluded the CO2 was the most important if not the only attractant from germinating wheat seeds.
98 citations
TL;DR: Although both species were carried beyond their northern limit for overwinter survival and little damage ensued, the usefulness of synoptic weather analysis in explaining sudden population increases is shown.
Abstract: An instance of medium-range migration by Rhopalosiphum maidis (Fitch) and of long-range migration by Spodoptera frugiperda (J. E. Smith) are documented and the weather systems that made the migrations possible are detailed. Although both species were carried beyond their northern limit for overwinter survival and little damage ensued, the usefulness of synoptic weather analysis in explaining sudden population increases is shown.
96 citations
TL;DR: An algorithm for simulation of variability in temperature-dependent development under constant and variable temperature regimes for Anthonomus grandis, Trichoplusia ni, and Heliothis zea is developed and validated.
Abstract: The simulation of variability in temperature-dependent development is discussed. An algorithm for simulation of this variability is developed and validated under constant and variable temperature regimes for Anthonomus grandis, Trichoplusia ni, and Heliothis zea.
96 citations
TL;DR: The life history of the European earwig at Vancouver, B.C., is described and divided into two periods: the nesting phase and the free-foraging phase, where developmental rates, population sizes, and sex ratios differ between the two habitats.
Abstract: The life history of the European earwig at Vancouver, B.C., is described and divided into two periods: the nesting phase and the free-foraging phase. Seasonal changes in population characteristics are documented and compared in sparsely and densely vegetated habitats. The developmental rates, population sizes, and sex ratios, but not the body weights, differ between the two habitats. Suggested reasons for these differences are advanced.
86 citations
TL;DR: The relationship between the temperature and the speed of development is described for the Kamloops ‘biotype’ of the pea aphid, Acyrthosiphon pisum, and some of its associated hymenopterous parasites.
Abstract: The relationship between the temperature and the speed of development is described for the Kamloops ‘biotype’ of the pea aphid, Acyrthosiphon pisum, and some of its associated hymenopterous parasites. The primary parasites are: Aphidius ervi ervi, A. ervi pulcher, A. smithi, and Praon pequodorum; and the secondary parasites are: Asaphes lucens and Dendrocerus niger. For each species the lower temperature threshold for development and the time-to-adult was determined under constant laboratory conditions using field-grown alfalfa as a host plant for the pea aphid and the first-generation offspring of field-collected aphids and parasites. The thermal constants enable the prediction of aphid and parasite population growth, as influenced by temperature, on a physiological time-scale.
76 citations
TL;DR: Well-fed, mated female spruce budworm show little activity during the first 24 h after emergence, while smaller, artificially starved females are much more active, especially during the second 24-h period, when many fly before ovipositing.
Abstract: Well-fed, mated female spruce budworm ( Choristoneura fumiferana (Clem.)) show little activity during the first 24 h after emergence. During the second 24 h they lay between 33 and 50% of their egg complement. During the third 24 h most flight activity occurs. Smaller, artificially starved females are much more active, especially during the second 24-h period, when many fly before ovipositing. Timing of oviposition and flight is under photoperiodic control: female flight occurs just before dark after peak oviposition while male activity starts before dark, but peaks after dark, with a morning peak of variable intensity.
65 citations
TL;DR: The evolutionary success of the mites, which rivals that of the insects, is reviewed briefly, and some thoughts on the usefulness of research on the interrelationships between mites and other arthropods are concluded.
Abstract: The evolutionary success of the mites, which rivals that of the insects, is reviewed briefly. A remarkable secondary adaptive radiation apparently occurred in the mites, probably beginning in the late Mesozoic, in conjunction with the major evolution and radiation of the insects and to a lesser extent of the higher plants and the warm-blooded vertebrate animals.The spectrum of forest floor microhabitats, in which mite–arthropod associations may occur, is discussed. The problems in elucidating the living relationships between mites and other arthropods, due to biological complexities and physical difficulties, are reviewed. Some of the elements of close mite–arthropod associations are discussed, including protected stable habitats provided by insects, shared habitat specificities, regularity of co-occurrence, host specificity, site constancy of mites on their arthropod hosts, and life cycle synchrony.Examples are given of the apparently few morphological adaptations of insects for accommodating mites. The variety of morphological structures which are adaptations of mites to an association with other arthropods are discussed, particularly regressive modifications. Physiological and behavioral adaptations of mites to secretions or to other actions of their arthropod associates are mentioned. Cases are given showing the different ways in which mites have achieved synchrony of their life cycle with that of their hosts.Some thoughts on the usefulness of research on the interrelationships between mites and other arthropods conclude the paper.
64 citations
56 citations
TL;DR: In this article, daily fecundity and survival data for apterous and alate virginoparous morphs of Acyrthosiphon pisum (Harris) reared on broadbean, Vicia faba (var. Exhibition Longpod), at 20 ± 1 °C.
Abstract: Data on daily fecundity and survival are presented for the apterous and alate virginoparous morphs of Acyrthosiphon pisum (Harris) reared on broadbean, Vicia faba (var. Exhibition Longpod), at 20 ± 1 °C. Alatae began to reproduce later, and produced fewer young over a longer period than did apterae, but lived no longer.Reproductive patterns of A. pisum apterae from a number of other clones are compared, and the patterns of some other species are discussed in relation to A. pisum apterae and alatae.
50 citations
TL;DR: The biology of Urophora cardui (L.), a European tephritid, and its suitability for introduction into Canada to aid in the control of the thistle are investigated.
Abstract: The biology of Urophora cardui (L.) (Diptera: Tephritidae) and its suitability as a biocontrol agent for Canada thistle (Cirsium arvense (L.) Scop.) were investigated. The incubation period of the eggs was 4.3 days at 27 °C. Crowding did not significantly reduce the longevity of the adults, the number of eggs laid, or the egg hatch. U. cardui overwinters as a mature larva in the gall but pupation and further development ensue when the larvae are exposed to air by opening the gall. The roots of single and double-galled plants weighed 65 and 78% less and the combined weights of the stem and leaves 47 and 58% less respectively than plants without galls. U. cardui is monophagous: it oviposits into Canada thistle and if kept without this host, into the closely related weeds Cirsium vulgare (Savi) Ten. and Carduus acanthoides L. U. cardui is a promising biological control agent and should be released in Canada.Canada thistle (Cirsium arvense (L.) Scop.) is a widespread noxious weed in Canada and the northern United States. This paper reports on the biology of Urophora cardui (L.), a European tephritid, and its suitability for introduction into Canada to aid in the control of the thistle.
TL;DR: Parasitism by Aphidius smithi reduced the fecundity and population growth of pea aphid, Acyrthosiphon pisum .
Abstract: Parasitism by Aphidius smithi reduced the fecundity and population growth of pea aphid, Acyrthosiphon pisum . Aphids that were parasitized during the first or second instar period died as fourth instars without producing offspring. Parasitized third or fourth instars usually reached maturity and produced a variable number of progeny. Parasitized adult aphids stopped producing nymphs approximately 7 to 8 days following attack by A . smithi . Equations are given for the relationship between the mean total fecundity, the intrinsic rate of increase, and the doubling time of apterous and alate viviparous pea aphid and the aphid age at the beginning of parasitism.
TL;DR: Using explosives, 93 grand fir trees were examined for root decay and bark beetle activity and it appears that root disease is an important factor in predisposing fir to attack by bark beetles.
Abstract: Using explosives, 93 grand fir were examined for root decay and bark beetle activity. Ninety-six per cent of the trees attacked by bark beetles also had root rot. From the data it appears that root disease is an important factor in predisposing fir to attack by bark beetles. Significant relationships were found between the presence of root decay and both the incidence of beetle attack and the number of attacks. No such relationship could be found concerning the success of beetle attacks. The question of bark beetles as vectors of root disease was not considered.
TL;DR: This is the first paper on Canadian Cretaceous chalcidoid fossils of the families Mymaridae, Trichogrammatidae, and Tetracampidae, based on 54 specimens representing 12 species from Manitoba and Alberta, and four new subfamilies are proposed.
Abstract: This is the first paper on Canadian Cretaceous chalcidoid fossils of the families Mymaridae, Trichogrammatidae, and Tetracampidae, based on 54 specimens representing 12 species from Manitoba and Alberta. Four new subfamilies are proposed, Triadomerinae (Mymaridae), Baeomorphinae, Distylopinae, and Bouceklytinae (Tetracampidae). Descriptions and remarks are given for Archaeromma nearctica n. gen., n. sp.; A. minutissima (Brues) (Mymaromminae); Triadomerus bulbosus n. gen., n. sp.; Carpenteriana tumida n. gen., n. sp.; Protooctonus masneri n. gen., n. sp. (Mymaridae); Enneagmus pristinus n. gen., n. sp. (Trichogrammatidae); Distylopus bisegmentus n. gen., n. sp.; Baeomorpha distincta n. gen., n. sp., B. dubitata Brues (transferred from Scelionidae, Prototrupoidea), B. elongata n. sp., B. ovatata n. sp. and Bouceklytus arcuodens n. gen., n. sp. (Tetracampidae). A list of all previously known fossil Chalcidoidea is provided. A table of primitive and specialized conditions of characters studied is given. The possible lines of phylogeny of families and genera of these fossils are discussed. Keys to the pertinent families and subfamilies and to the fossil species of Baeomorpha are provided. Photomicrographs of species treated are included.
TL;DR: In this paper, a mathematical pest population model is presented which can be used for dynamic economic and ecological evaluation of alternative control strategies, which is an illustration of a whole class of models that promises to remove pest control strategies from the category of ad hoc decisions.
Abstract: The development of physiological resistance in insect populations of agricultural and public health importance to insecticides and other methods of control has taken on proportions of increasing importance. In this paper, a mathematical pest population model is presented which can be used for dynamic economic and ecological evaluation of alternative control strategies. Because of the unique nature of pest populations, the model is not directly applicable to all actual problems. However, the model is an illustration of a whole class of models that promises to remove pest control strategies from the category of ad hoc decisions.For those empirical problems for which a benefit function can be defined, dynamic programming is suggested as a method for determining an optimal strategy over time. When it is difficult or impossible to specify a benefit function, which is frequently the case, it is suggested that Monte Carlo techniques, applied to the pest control strategies of interest, be used to determine the effects on the pest population over time.
TL;DR: A potent sex pheromone produced by female bertha army worm moths was isolated and a 16 carbon, unsaturated, alkenol acetate was indicated from chemical degradative and GLC retention data.
Abstract: A potent sex pheromone produced by female bertha army worm moths was isolated. A 16 carbon, unsaturated, alkenol acetate was indicated from chemical degradative and GLC retention data. The location and configuration of the double bond was determined from the antennal responses (EAG) of male moths to a series of cis and trans mono-unsaturated alken-1-ol acetates; cis -11-hexadecen-1-ol acetate elicited the greatest EAG response. GLC retention times of the purified insect sex pheromone corresponded exactly with those of authentic cis -11-hexadecen-1-ol acetate on several analytical columns. Maximum biological response in laboratory bioassays of synthetic materials was obtained from a mixture of approximately 85% cis - and 15% trans -11-hexadecen-1-ol acetates.
TL;DR: The classification of the Aphrodinae is reviewed in this paper, where the subfamily is redefined to include the Deltocephalinae (Euscelidae) and Hecalinae, and nine tribes are recognized: Eupelecini, Paradorydiini, Stirellini, Paraboloponini, Aphrodini, Krisnini, Selenocephalini, Hecalini, and Delto-cephalini.
Abstract: The classification of the Aphrodinae is reviewed. The subfamily is redefined to include the Deltocephalinae (“Euscelidae”) and Hecalinae, and nine tribes are recognized: Eupelecini, Paradorydiini, Stirellini, Paraboloponini, Aphrodini, Krisnini, Selenocephalini, Hecalini, and Deltocephalini. The tribe Aphrodini is divided into six subtribes: Doraturina, Achaeticina, Anoterostemmina, Neobalina, Aphrodina, and Xestocephalina. The tribe Deltocephalini is divided into six subtribes: Deltocephalina, Athysanina, Cicadulina, Macrostelina, Platymetopiina, and Cochlorhinina. Keys are provided to the tribes and subtribes, and the Holarctic taxa are defined, with their Holarctic genera listed under each.
TL;DR: Evidence from studies in large field cages indicated that odor from virgin male apple maggot flies, Rhagoletis pomonella (Walsh), was attractive to virgin females, but the principal role of this odor in mating behavior is uncertain.
Abstract: Evidence from studies in large field cages indicated that odor from virgin male apple maggot flies, Rhagoletis pomonella (Walsh), was attractive to virgin females. Whether the principal role of this odor in mating behavior is in fact that of a female attractant or rather that of an aphrodisiac is uncertain and awaits further study.
TL;DR: A large number of Simulium venustum Say flies were released in rapids in the Chalk River near the village of Chalk-River, Ont., to complete development and disperse as adults as discussed by the authors.
Abstract: Large numbers of black flies, mostly Simulium venustum Say, were labelled as larvae with 32 P and released in rapids in the Chalk River near the village of Chalk River, Ont., to complete development and disperse as adults. Flies were trapped over a 900 square mile area for 3 months after the release, and radioactive flies from the traps were identified at CRNL by means of an autoradiographic technique. The distance travelled by the flies could be described by a normal distribution curve, with the average migration between 5.8 to 8.2 miles. A few individuals were trapped at a distance of 22 miles 2 days after emergence, and some crossed the Ottawa River which is at least a mile wide at the point nearest the release area. Some traps caught very high numbers of radioactive flies, one at about 6 miles from the release center accounting for more than 1300 tagged flies. The traps giving the highest number of tagged flies (e.g., > 100) were clustered in two distinctive areas, one west and one large area south of the release point. The results indicate that control measures should be applied to black fly streams at least 10 miles from critical areas such as towns.
TL;DR: Mites overwinter on the diapausing adult beetles and do not infest the immature stages of their host and even at high population levels, the mites do not noticeably affect the longevity or fecundity of their hosts.
Abstract: Adult females of Chrysomelobia labidomerae Eickwort lay eggs on the upper surfaces of the hind wings of Labidomera clivicollis (Kirby). The eggs hatch in approximately 7 days and male and female larvae feed at the base of the wings and in the meso–metathoracic crevice and swell to about twice their original length. For about the second half of the approximately 7-day larval stadium, the larvae are inactive (pharate adults) and are usually cemented to the undersurfaces of the elytra. Inactive female larvae are accompanied by adult males that apparently copulate with the newly emerged adult females. The pharate adult is enclosed in a cuticular sac that may represent a calyptostatic nymphal instar. Adult females feed on the beetle’s abdominal terga and sometimes also occur on its venter where they do not feed. Females disperse from host to host when the beetles copulate. The species is arrhenotokous. Mites overwinter on the diapausing adult beetles and do not infest the immature stages of their host. Even at high population levels, the mites do not noticeably affect the longevity or fecundity of their hosts.
TL;DR: It is stated that the establishment and acclimatization of this species in Quebec was successful, and that increased reproduction and spread is anticipated.
Abstract: A brief history of the importance attributed to red wood ants in Europe and the outstanding qualities of three species, Formica lugubris Zett., F. polyctena (Foerst.), and F. aquilonia Yarr., are presented. The reasons for choosing F. lugubris as a suitable species for introduction to Canada are given. The collecting in Italy, shipping by air to Canada, and eventual release in Quebec is discussed. In conclusion it is stated that the establishment and acclimatization of this species in Quebec was successful, and that increased reproduction and spread is anticipated.
TL;DR: The biology of Coenagrion angulatum Walker and C .
Abstract: The biology of Coenagrion angulatum Walker and C. resolutum Hagen in Saskatchewan has been studied. In these species embryonic development begins as soon as the eggs are laid and is completed in the field within 3 weeks. Larval development is rapid and larvae in the final instar were first collected before the middle of September. Development ceases during the first 2 weeks of October when the water temperature is about 2 °C. By this time the majority of larvae are in the last three instars. Larvae overwinter frozen in the ice 15 to 20 cm below the pond surface. They are able to survive temperatures as low as −5° to −6 °C though these extremes are not normally experienced in the field because of snow cover. Although the study pond filled with runoff water by mid-April no change in the larval population structure occurred until mid-May. Emergence, which is highly synchronous, begins in the last week of May. However, it is governed by the prevailing air and water temperatures, and occurs only when the mean daily water temperature exceeds 12 °C and the mean maximum air temperature reaches 20° to 21 °C. Most insects emerge within 10 days of the first appearance of the adults. Sexual maturation takes about 1 week. Oviposition occurs while the pair are in tandem. Preferred oviposition sites are the submerged portions of stalks of floating plants such as Utricularia, Ranunculus, and Potamogeton. The observations are discussed in terms of the species’ ability to survive the climatic extremes of central Canada.
TL;DR: The salivary glands of female Culex pipiens L each consist of three lobes divisible into five regions as mentioned in this paper, and the axon of presumed neurosecretory function was found associated with the neck region of the medial lobe.
Abstract: The salivary glands of female Culex pipiens L each consist of three lobes divisible into five regions. Fine structure indicates that two regions may be involved in solute-linked water transport and three regions may have a glandular function. The fine structure is similar to that reported for Anopheles stephensi and Aedes aegypti. In C. pipiens, an axon of presumed neurosecretory function was found associated with the neck region of the medial lobe.Complete development of the salivary glands occurs between the first and fifth days of adulthood. Morphological changes associated with blood-feeding were limited to the presence or absence of the salivary secretions in the apical cavities and duct lumen. During blood-feeding the contents of two of the glandular regions are voided, being replenished within 24 h Results are related to previous histochemical studies of the salivary glands of mosquitoes.
TL;DR: The toxicity of a number of insecticides was tested against three species of springtails (Collembola), Folsomia candida (Willem), Onychiurus justi porteri (Denis), and Hypogastrura armata (Nicolet), which were cultured in the laboratory.
Abstract: The toxicity of a number of insecticides was tested against three species of springtails (Collembola), Folsomia candida (Willem), Onychiurus justi porteri (Denis), and Hypogastrura armata (Nicolet), which were cultured in the laboratory. Treatment was accomplished by incorporating the insecticide into moist Plainfield sand and exposing the springtails for 24 h on this substrate. Generally, the order of toxicity of the insecticides to all three species was: Counter® (phosphorodithioc acid S- (tertbutylthio) methyl O,O diethyl ester) > phorate > carbofuran > heptachlor > methomyl > chlorfenvinphos. Acephate, leptophos, p, p′-DDT, and chlordimeform were of low toxicity to all species. More significantly, however, there were large interspecific differences in susceptibility to insecticides; fensulfothion was virtually non-toxic to O. j. porteri (LD50 > 80 p.p.m.) but highly toxic to F. candida (LD50 = 0.1 p.p.m.). Results of these tests suggest that extrapolation of toxicity data from one species of springtail to other species would be unwarranted.