This paper deals with the influence of bark moisture and temperature on the hehaviour of the egg-laying female within the host. Fecundity of the insect will he discussed, as well as internal changes associated with the behavioural pattern. The life-cycle, brood development, and time of flight was described in Part I of the present series. The behaviour during mating, egg laying, and gallery construction were described earlier (Reid 1958b).

Resistance was documented in 1995 to commonly used organophosphorus, carbamate, and pyrethroid insecticides in populations of western flower thrips, Frankliniella occidentalis (Pergande), from six commercial greenhouses in Ontario. Adult female thrips were placed in glass vials treated with technical-grade insecticides and mortality at 18 h was compared with a single discriminating concentration, the computed LC99 of a reference laboratory population. Baseline dose–response regressions for insecticides commonly used in Ontario greenhouses were obtained for the laboratory population of western flower thrips. The organophosphorus compounds chlorpyrifos and malathion and the carbamates methomyl and bendiocarb were the most toxic materials tested; whereas the pyrethroid deltamethrin and a phosphoroamidate acephate were the least toxic. The addition of piperonyl butoxide to solutions of deltamethrin was highly synergistic. The mixture of deltamethrin and endosulfan (1:1) was moderately synergistic. Populations of western flower thrips from commercial greenhouses were resistant to deltamethrin, but deltamethrin mixed with piperonyl butoxide or endosulfan was synergistic in all cases. None of the populations were resistant to all of the insecticides tested. Recommendations are presented for the development of a resistance-management strategy for western flower thrips.

Although the structure of the ovipositor of parasitic Hymenoptera is largely uniform, interspecific variation in its morphology can be observed. Such variability may be related to the diversity of hosts attacked. To verify such an hypothesis, we compared, using correspondence analysis, the morphological characteristics of the ovipositors of 20 species in three categories: (i) species belonging to the same taxonomic unit and attacking the same type of host, (ii) species belonging to the same taxonomic unit but attacking different types of host, and (iii) species belonging to different taxonomic units but attacking the same type of host. Results show that variability in some morphological traits of the ovipositor can be related to host characteristics. Adaptive convergence in morphological variations observed between species is discussed.

The utility of the ‘random predator equation’ of Royama (1971) and Rogers (1972) as a summary of the functional response relationship between predatory feeding behavior and prey density is questioned on the grounds that statistical assumptions in the regression analysis are not met by the linearized form of the equation. The absence of an alternative linearization that does not violate these assumptions necessitates the use of Holling's (1959) disc equation for the description of experimentally derived functional response relationships, when the comparison of parameters of different populations of predator or prey is a more important objective than a precise estimation.

The statistical validity of the traditional linearization of the disc equation is questioned. An alternative transformation is proposed, which removes the statistical problems associated with the former transformation, and which permits a higher degree of explanation of variance in the independent variable by the regression.

The physical association between Dendroctonus ponderosae Hopk. and its associated blue stain fungi Ceratocystis montia Rumb. and Europhium clavigerum Robinson and Davidson and the yeasts Pichia pini (Holst) Phaff, Hansenula capsulata Wickerham, and H. holstii Wickerham is described in single broods reared in bolts of lodgepole pine, Pinus contorta Dougl. var. latifolia Engelm. Eggs just prior to hatch and first-instar larvae were always in contact with the microorganisms whereas newly laid eggs, second-, third-, and fourth-instar larvae were not. During pupation, blue stain fungi and yeasts colonized pupal chamber walls. Transfer of these microorganisms to the new generation of insects was ensured when tenerals contacted the microorganisms lining the pupal chamber. Ensured physical contact between these organisms supports the hypothesis of a symbiosis between them.

A great number of papers and notes have been written on the root maggots attacking cabbage, cauliflower, turnip, and radish in Canada and the United States during the past 75 years. These deal chiefly with the occurrence, life-history, and control of the cabbage maggot, Hylemya brassicae (Bouché), or species which have been misidentified as that species. The Canadian work has followed the lead of Gibson and Treherne (1916), but in spite of the accumulation of information on the life-history of the species, on cultivation methods, and on insecticides, the pests of these cruciferous plants remain as noxious as ever.

An outbreak of the European spruce sawfly, Diprion hercyniae (Htg.), was discovered in the Gaspé Peninsula in 1930. By 1938, heavy infestations had developed west of the Gaspé Peninsula in Quebec, throughout New Brunswick and northern Maine, and in parts of Vermont and New Hampshire. Moderate to light infestations occurred through all other parts of the spruce forests of this region and extended from Nova Scotia, to the north shore of the St. Lawrence River, and west to Ontario.

The seven-spotted lady beetle, Coccinella septempunctata L., was first reported in Manitoba in 1988. The effect of this introduced species on the relative abundance of the more common native coccinellines was determined from D-Vac Insect Net® and sweepnet samples in alfalfa in 1983–2001, by sweepnet and visual sampling in field crops and other vegetation in 1989–2001, and by transect sampling of aggregations of coccinellines in spring and autumn on the shore of Lake Manitoba from 1989 to 2001. The trends of annual changes in the abundance of six species in southern Manitoba were similar, whether based on the mean density per 200 sweeps in alfalfa or on their relative abundance in alfalfa, on other vegetation, and in aggregations on the beach. Before 1988, Hippodamia tredecempunctata tibialis (Say), Coccinella transversoguttata richardsonii Brown, and Hippodamia convergens Guerin were the most abundant species, followed by Hippodamia parenthesis (Say) and Coccinella trifasciata perplexa Mulsant. By 1992, C. septempunctata had become the dominant species, but H. tredecempunctata has since been the dominant species in most collections. The relative abundance of C. transverso guttata, H. convergens, H. parenthesis, and C. trifasciata has decreased since the establishment of C. septempunctata. The decline in abundance of these species seems to be caused by their competitive displacement by C. septempunctata. Their displacement also might be a contributing factor in the slight increase in abundance of H. tredecempunctata because C. septempunctata may compete less directly with this species than with other native coccinellines.

One or more insects were captured during 1 week in probe traps placed in granaries holding wheat, barley, or oats in 51% (n = 116) of grain bulks in the fall of 1986, 88% (n = 111) in the summer of 1987, and 85% (n = 106) in the fall of 1987. Fungivorous insects were the most common and predominant group at all sampling times. Granivorous species were the rusty grain beetle, Cryptolestes ferrugineus (Stephens), and the red flour beetle, Tribolium castaneum (Herbst). Grain in galvanized steel and wooden granaries was usually infested with insects to the same extent; granaries with or without aeration systems usually contained the same number of species; small bulks of grain often were infested less frequently than large bulks; the presence of livestock feed on farms did not result in greater insect incidence; and insecticide use in granaries did not prevent re-infestation of grain and insecticide use increased from 24% in 1986 to 31% in the fall of 1987. The kinds of insects detected in grain stored with various farming practices, and co-occurrence with other arthropods in the grain provides baseline information on potentially changing patterns of infestation.

Arthropods associated with Populus coarse woody material (CWM) were sampled from aspen-mixedwood stands in north-central Alberta using rearings from wood bolts and flight-intercept traps attached to snags. More than 39 000 arthropod specimens were collected over 3 years, comprised mainly of Coleoptera, Diptera, Hymenoptera, and Acari. Detailed analyses are provided to compare the number of species, standardized abundance, and trophic structure between collecting methods for 257 saproxylic species of Coleoptera. Abundance of beetle species, from both rearings and window traps, and rarefaction estimates of species richness indicate little difference between methods with respect to expected number of species. However the abundance of particular beetle families differed significantly between methods, with the Aderidae, Anthicidae, and Scaphidiidae collected mainly in rearings and the Micropeplidae, Bostrichidae, Cephaloidae, Clambidae, Salpingidae, and Tenebrionidae more commonly collected with window traps. Fungivorous and predatory beetles were more abundant in CWM than wood borers, scavengers, or taxa with undetermined feeding habits, but the two methods revealed similar overall trophic structure. To census the variability in saproxylic arthropod faunas from CWM, a combination of collecting methods is recommended.

Evidence is presented to suggest that the gypsy moth, Porthetria dispar (L.), is numerically self-regulating through a shift in the quality of individuals induced by changes in nutrition. This qualitative change affects dispersal, behavior, developmental rate, and fecundity, and this provides P. dispar with the ability to respond to intrinsic and extrinsic factors faster and more efficiently than if dependent on selection. Adaptability is further facilitated because the change in quality can be induced either in the previous generation by the amount of nutrient reserves provided the eggs, or during the current generation by hunger, crowding, or cool temperature. This change is best characterized by an increase in the number of larvae with additional instars. In these larvae, a prolongation of instar I and a shift in behavior increases their potential for dispersal. The similarities and differences between P. dispar and Malacosoma pluviale (Dyar) are discussed.

The family Otopheidomenidae Treat is transferred to the Phytoseiidae Berlese as a subfamily, and the subfamily Macroseiinae Chant et al. is considered as a genus in the subfamily Phytoseiinae. The subfamily Otopheidomeninae contains four genera: Otopheidomenis Treat, Hemipteroseius Evans, Treatia Krantz and Khot, and Entomoseius Nov. The subfamily Phytoseiinae contains 10 genera: Typhlodromus Scheuten, Phytoseius Ribaga, Chantia Pritchard and Baker, Platyseiella Muma, Iphiseius Berlese, Paraamblyseius Muma, Phytoseiulus Evans, Amblyseius Berlese, Macroseius Chant et al., and Gigagnathus Nov. Keys and descriptions of genera are included.

Female mountain pine beetles, Dendroctonus ponderosae Hopkins, were exposed to papers soaked in outer bark extracts of lodgepole pine, Pinus contorta Douglas var. latifolia Engelmann. Both benzene and methanol–water extracts elicited greater feeding activity than did controls. Non-polar host compounds exhibited greater incitant (initiation of feeding) properties, while polar compounds were more powerful stimulants (continuation of feeding). No differences were detected in feeding on extracts from resistant or susceptible trees. Repellency appears to be associated with beetle responses to active host metabolism.

The spontaneous activation of Aedes aegypti, and their responses to external stimuli (especially changes in temperature, humidity and carbon dioxide concentration) have been analyzed in a way that allows the controlling neural mechanisms to be inferred. In general, the flying insect turns back on leaving a favorable air stream, but does not turn on entering one. The normal attack program reduces to four basic steps: a general search initiated by a small rise in the CO2 level, no turn when the insect enters the "host stream" (i.e., the convective or other air current whose temperature and/or relative humidity has been modified by the host), an induced turn on leaving the host stream, and a visual landing. Repellents resemble CO2 in activating previously resting mosquitoes. If, however, the host stream contains a repellent vapor, the insect is made to turn on entering the host stream and is prevented from turning on leaving it. Thus the repellent vapor reverses the normal response to the host stream in two ways that are vital to success in locating a warm-blooded host. It also tends to inhibit probing. The antennal setae through which the various environmental influences are perceived can be inferred from a quantitative consideration of the responses.

Normal matings of Choristoneura fumiferana (Clem.) resulted in the transfer of single, persistent spermatophores. The mean duration of copulation was 4 hours with a range from 21/2 to 81/2 hours. All the first matings of males were fertile and the spermatophores were large, while an increasing proportion of the subsequent matings were infertile and the spermatophores became progressively smaller. Only fertilized females laid normal numbers of eggs. There was no evidence to show that insemination can be accomplished without the transfer of a spermatophore. However, the presence of a spermatophore in the bursa of the female was not always indicative of successful insemination.Males mated only once within a 24-hour period; they were least responsive to females just after emergence (< 0.5 day old) and most responsive when 2 to 4 days old. Females mated most readily when < 0.5 day old and became progressively less attractive or less receptive with age. Mated females were not as attractive as unmated females.

Fir engraver and Douglas-fir beetle numbers were monitored during and after an outbreak of the Douglas-fir tussock moth. The population behavior of the two species of bark beetles was similar. Number of emerged offspring/female was highest during the years of defoliation and declined afterward. Total number of beetle attacks peaked 1 to 2 years after defoliation ended and then declined. During and 1 year after defoliation, beetles generally infested trees that had greater than 90% defoliation. After this time infestations were not as strongly associated with heavily defoliated trees. Life tables were constructed for beetles within trees and for beetles per area of forest land. Key mortality factors acting on beetles within trees occurred during the larval and pupal stages. Mortality during adult dispersal was a key factor when beetle density per area of land was considered. Although beetle offspring emerging per dm2 of bark surface was relatively low in defoliated trees, defoliation appeared to reduce host resistance which enabled beetles to successfully attack at lower densities, reducing intraspecific competition, and resulting in increased emergence of offspring/female parent.

The upwind guidance of flying insects was considered in a previous paper (Wright, 1958) where a homing mechanism was suggested that did not require visual contact with the ground. The response of Drosophila to attractive scents presented in various ways has now been studied. The results show that visual contact with the ground is in fact essential, and other factors of the guidance system have been clarified.

Female Nasonia vitripennis (Walk.) parasitizing housefly (Musca domestica L.) pupae produce a smaller percentage of female progeny at high parasite:host ratios than at lower ones because they fertilize a smaller percentage of their eggs (in this species unfertilized eggs produce male progeny), and because more female than male larvae die on superparasitized hosts. The adult females fertilize relatively fewer eggs at high than at low parasite:host ratios for two reasons. First, they encounter relatively more previously attacked hosts, on which they lay a smaller percentage of fertilized eggs than on previously unattacked ones; second, they more often encounter other female parasites while ovipositing, and this interference reduces the percentage of fertilized eggs they lay.

We review the existing literature on patterns of moth (Lepidoptera) species richness and community composition in northeastern Nearctic forest ecosystems across hierarchical scales ranging from individual trees to entire managed ecoregions. Moths are species-rich in northeastern forests of North America, with the most diverse families being Noctuidae and Geometridae. Individual trees and forest stands, however, are often dominated by few species. Climate, stand age, disturbance regime, and landscape heterogeneity are significant predictors of abundance of dominant species. Most other moth species in the regional pool are patchily distributed and appear to occur regularly at very low abundance. Moth communities respond predictably to forest-management practices, and the outcomes of postmanagement response are largely driven by changes in the plant community. Significant reductions in moth species richness and changes in community composition are correlated with clear-cut harvesting, whereas selective logging appears to cause more moderate changes in moth community structure. Broad-scale effects of forest fragmentation on moth communities in unglaciated regions are best described by species replacement rather than species loss; moth species richness decreases slightly across a gradient of fragment sizes, but shifts in moth community composition are more important, especially in the relative importance of herbaceous-plant-feeding species in large and small fragments. Species that appear to be most sensitive to timber management or habitat loss are dietary specialists as larvae, dispersal-limited as adults, or dependent on commercially valuable tree species such as oaks, Quercus L. (Fagaceae). Restored forest stands tend to converge in terms of lepidopteran species dominance and diversity among stands, suggesting that the long-term consequences of timber management or habitat loss include a significant reduction of regional β-diversity. Finally, future research on forest Lepidoptera should include an emphasis on understanding the role of urban woodland habitat in retaining viable and diverse moth communities and how the spatial pattern of timber harvest affects the relative magnitude of α- and β-diversity components within a given ecoregion.

As will be apparent, a study such as this serves a dual purpose in elucidating certain problems of phylogenetic relationships, either broad or narrow, and at the same time allowing the demonstration of the means by which the chromosomes themselves have undergone changes in their number, morphology, or mechanical properties, during the course of their phylogeny. That is to say, such lines of investigation have a direct appeal to both the taxonomist and the pure cytologist.