Adults and larvae of the cottonwood leaf beetle, Chrysomela scripta Fab., defoliated tissue cultured Aigeiros (Populus × euramericana (Dode) Guinier) subclones and destroyed apical tips. Fecundity was 510 ± 153 eggs . Four generations occurred between May and September in southern Wisconsin. Maximal insect numbers and damage occurred in the third generation. The minimal developmental threshold was 10.8 °C with a mean 257 ± 26 day-degree (°C) required per generation. Important biological control agents included Coleomegilla maculata, which consumed up to 25% of the eggs, and Shizonatus latus, a pteromalid parasite, which destroyed up to 26% of the pupae.

In eastern Canada larvae of the spruce budworm, Choristoneura fumiferana (Clem.), complete their development in one year, undergoing only one period of winter diapause in the second instar, whereas in certain parts of British Columbia, at high altitudes, two years are normally required for development, the larvae spending a second period of winter diapause in the fourth instar (3, 9). Among laboratory-reared eastern budworm there are a few individuals that enter a similar second diapause (7). The low incidence and somewhat irregular occurrence of this second diapause in eastern budworm, even in laboratory rearings, have hitherto made detailed studies almost impossible, but unusual storage times and treatments used recently in rearing experiments had the unexpected effect of increasing the incidence of this tvpe of behaviour to a level where experimental analysis became possible. This paper describes these larvae and their behaviour; an account of the effects of various conditions upon the incidence of second diapause will be presented later.

The alfalfa plant bug, Adelphocoris lineolatus (Goeze), a well-known pest of alfalfa in Europe and the United States, was first recorded in Saskatchewan in 1947, in the Hudson Bay district about 16 miles west of the Manitoba border. By 1959 it had spread westward through the northern agricultural area of the province to within 35 miles of the Alberta border. Economic infestations appeared within two to four years of its initial occurrence in each district.

The migratory behaviour of the adult, which is apparently essential for maximum reproduction, effects rapid dispersal of the species. Also, because of this migratory behaviour control measures may have to be undertaken each year, and seedling stands may be infested in the first crop year.

The seasonal development of the insect is described. Apparently in the spread of the insect northward a univoltine population is being selected. Eggs that have overwintered in stems hatch in late May and early June. Development proceeds through five nymphal instars, and adults begin to appear toward the end of June. These adults lay eggs during the latter part of July. Most of the eggs enter diapause: less than five per cent of them hatch the same year, and any second-generation adults that do occur do not have time to mate and lay eggs before all activity is halted by freezing weather.

The main host plants of A. lineolatus are two cultivated legumes, alfalfa, Medicago media Pers., and red clover, Trifolium pratense L. No native host plants have been found in Saskatchewan.

About three per cent of field-collected nymphs from the Nipawin district were parasitized by braconid larvae tentatively identified as Euphorus pallipes (Curtis).

Captive colonies of Vespula arenaria (Fabricius) and Vespula maculata (Linnaeus) were placed in the field during the summer and fall of 1972. The adults were free to forage, and the colonies developed normally. Nest temperatures were recorded at mid-afternoon, 6 days per week. Once each week, colonies were confined, brought into the laboratory, and placed in a cold room at 5 °C for 4 h. At the end of this period, the nest temperatures were recorded and the colonies returned to the field. Under field conditions, V. arenaria colonies maintained an average daytime nest temperature of 31 °C, and V. maculata colonies maintained an average daytime nest temperature of 29 °C. As they developed, colonies of both species were increasingly capable of resisting cooling at an ambient temperature of 5 °C. This ability to thermoregulate under extreme conditions peaked in early August for V. arenaria and in late August for V. maculata. In both species, the decline in the ability to thermoregulate was associated with the production of reproductives. It appears that the major function of thermoregulation in these two species is to provide a favourable temperature for the development of the young rather than to provide the colony with protection against low ambient temperatures.

The fungus Metarrhizium anisopliae (Metch.) Sor., which causes a disease in insects known as green-muscardine, was first used by Metchnikoff in 1879 to infect insects artificially. Subsequently it was widely tested as a control agent with a few encouraging results (Steinhaus, 1949).

From 1951 to date the disease was common in a moderately dense population of the introduced elaterid wireworm Agriotes obscurus (L.) near Dartmouth, and much less prevalent in a very dense population of a related introduced species, A. sputator (L.), near Digby. The higher incidence of the disease near Dartmouth was tentatively attributed to the fact that this area has greater annual rainfall and is more subject to coastal fogs than is Digby. These observations led to the culturing and testing of the fungus in the laboratory and to attempts to increase the incidence of the disease at both Digby and Dartmouth by artificial dissemination of the spores in the soil.

Observations suggesting that mature larvae of some carrion flies (Piophilidae) tend to leap off carcasses during rain motivated an investigation of the ontogeny and possible functions of larval leaping behaviour and larval responses to two stimuli associated with rain: moisture and sound. These behaviours were investigated in larvae of Prochyliza xanthostoma Walker (Diptera: Piophilidae) by means of laboratory and field observations and experiments. Mature larvae left their feeding substrates (rotting meat) in response to either moisture or rattling sound. The response to moisture was exhibited also by immature larvae. Once on the carcass surface, however, only mature larvae leaped off and pupated in the surrounding soil. The response to sound and the ability to leap only appeared late in larval development and were lost in the prepupal stage. Because rain may facilitate larval locomotion on carcass surfaces, and leaping appears to represent a more rapid and efficient means of leaving a carcass than creeping, these responses may reduce the metabolic costs and predation risks experienced by mature larvae moving to pupation sites in the soil. Thus, the ability to leap and the responses to moisture and sound may represent “ontogenetic adaptations” associated with a brief stage of larval development.

The adult densities of Hippodamia tredecimpunctata tibialis (Say), Coccinella novemnotata Hbst., and Coccinella transversoguttata richardsoni Brown, on corn fluctuated in July and August and reached their maxima at pollination, whereas the density of Coleomegilla maculata lengi Timberlake fluctuated much less. C. maculata, H. tredecimpunctata, and C. transversoguttata were more numerous on plants with a liver diet applied to their foliage than on untreated plants. H. tredecimpunctata, C. novemnotata, and C. transversoguttata were less numerous on plants that had their tassels removed and produced no pollen than on intact plants. C. maculata, H. tredecimpunctata, and C. transversoguttata were more numerous on plants exposed to the maximum amount of sunshine than on plants that were shaded for part of each day. H. tredecimpunctata was more numerous on plants situated at low elevation than at high elevation, whereas C. transversoguttata was more numerous at high than at low elevation. C. maculata and H. tredecimpunctata were more numerous on plants near the middle of a corn field than on plants at the perimeter of a field adjacent to buckwheat, whereas C. novemnotata and C. transversoguttata were most numerous on plants near the perimeter. Two-species associations of C. maculata and H. tredecimpunctata, C. novemnotata and H. tredecimpunctata, C. novemnotata and C. transversoguttata, and C. novemnotata and H. tredecimpunctata occurred on individual plants. Plant density and time of planting affected coccinellid density. Adult density was greatest at a plant density of 3.2 plants per square metre and adults were more numerous on early than on late planted corn.

Various genotypes of seven species of Brassicaceae (Brassica rapa L., B. napus L., B. juncea (L.) Czern., B. nigra (L.) Koch, B. tournefortii Gouan, Sinapis alba L., Crambe abyssinica Hochst. ex R.E. Fries, and B. napus × S. alba) were evaluated for susceptibility to infestation by the cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham). In the field, weevils were counted by excising and dissecting pod samples weekly for the presence of eggs, larvae, and larval exit holes. In the laboratory, excised pods from potted plants were exposed to gravid female weevils for 24 or 48 h and then the numbers of eggs and (or) feeding punctures were assessed. Differences in susceptibility of Brassicaceae species to the cabbage seedpod weevil were relatively consistent in both field and laboratory studies. Brassica rapa was the most susceptible. Intermediate susceptibility was observed for B. napus, B. napus × S. alba, B. tournefortii, and B. juncea, although the last species displayed some antixenotic resistance. Sinapis alba, B. nigra, and C. abyssinica were least susceptible. Pods of some species more frequently contained single, rather than multiple, larvae and this may have important implications for total yield loss, particularly in areas where opportunistic pests utilize weevil exit holes to gain access to seeds. New-generation adults fed on all Brassicaceae, and therefore all species may be susceptible to some yield loss. Canola growers in regions infested with C. obstrictus at high population densities can reduce losses by seeding S. alba, B. juncea, or a less susceptible genotype of B. napus.

An unique development in insect dietetics is announced, namely, the rearing of an hymenopteran — Itoplectis conquisitor (Say), an ichneumonid endoparasitoid of other insects — axenically on a chemically-defined synthetic diet. First heuristic attempts produced a yield of about 17% adults.

The relationship between the phenological development of the spruce budmoth (SBM), Zeiraphera canadensis, and that of its primary host, white spruce, was studied in New Brunswick using descriptive indices for both insect and host development. Larval emergence of SBM was synchronized with bud burst of white spruce, the species on which most eggs are laid. Subsequent SBM larval development can be estimated through reference to the development index for white spruce. For black, Norway, and red spruce, initial bud burst occurred approximately 15, 3, and 15 days, respectively, later than white spruce and this asynchrony is probably one of the reasons why the SBM is not an important pest on these tree species.

In southern Alberta the fundatrix of P. betae hatches from the overwintered egg in late April and early May and feeds on an emerging leaf of P. angustifolia or P. balsamifera, forming a gall. In the gall it produces alate fundatrigeniae, which migrate from the poplars to beets and produce apterous alienicolae. This form of the aphid reduces both yield and sugar content of beet roots. During the summer several generations of alienicolae are produced. In the fall most of the alienicolae produce sexuparae. These migrate from beets to poplars, where they produce males and oviparae. Each fertilized ovipara lays a single egg on the bark of a poplar tree. The species may overwinter as eggs on the poplars or as alienicolae in the soil. The egg has an obligatory diapause that is terminated by exposure to low temperature. The fungatrigeniae migrate from late June to mid-August and the sexuparae from early September to late October. The potential reproductive capacities of the fundatrix, fundatrigenia, sexupara, and ovipara averaged 163, 13, 6, and 1, respectively. Under greenhouse conditions 20 aphids (alienicolae) produced 9,000 in 6 weeks when the soil temperature was maintained at 27 °C. Below 15 °C. the rate of reproduction was low and death was caused by exposure to 30 °C. for 6 weeks. The most important predators of P. betae were the anthocorid A. antevolens, the flies S. bigelowi, L. pemphigae and T. glabra, and a coccinellid Scymnus sp.

The genus Ismarus Haliday of the New World is revised. Twenty-one species are recognized, described, and keyed, of which the following 16 are new: I. brevicornis n. sp. ♂ (Mexico), I. clarkae n. sp. ♀ (Canada), I. dux n. sp. ♂ (Panama, Costa Rica), I. flavicrus n. sp. ♀ (Mexico), I. flavigena n. sp. ♂ (Canada, U.S.A.), I. gibsoni n. sp. ♀ (Canada, U.S.A.), I. gracilis n. sp. ♀ ♂ (Mexico, Panama), I. helavai n. sp. ♀ (Panama), I. masoni n. sp. ♀ ♂ (Mexico), I. mexicanus n. sp. ♀ ♂ (Mexico), I. neotropicus n. sp. ♀ ♂ (Brazil), I. porteri n. sp. ♂ (Argentina), I. orion n. sp. ♀ (Mexico), I. rex n. sp. ♀ ♂ (Mexico), I. varicornis n. sp. ♀ (Brazil), and I. vigil n. sp. ♂ (U.S.A.). The hitherto unknown males of I. americanus Fouts and I. nevadensis Kieff. are described. I. rugulosus Foerst., I. halidayi Foerst., and I. flavicornis (Thorns.), previously known from Europe, are recorded from Canada and the U.S.A. Higher classification, interrelationships, and world distribution of Ismarus are discussed.

We studied life history traits of Xenos peckii Kirby (Strepsiptera: Xenidae), a little-known parasite of the paper wasp Polistes fuscatus (Fabricus) (Hymenoptera: Vespidae) in North America. We field-collected 24 wasp nests in early July 2012, isolated parasitised wasps, tracked life history events of X. peckii, and recorded such behaviour as emergence of males and mating by normal-speed and high-speed cinematography. To emerge, males first cut the puparium with their mandibles along an ecdysial suture line, and then push aside the pupal cap during emergence. The endoparasitic females engage in active calling (pheromone release) behaviour by slowly inflating their cephalothorax, and then extruding it even farther out of, and tilting it away from, the host wasp abdomen. Seasonal and diel (afternoon) emergence periods of males coincide with seasonal and diel receptivity and calling periods of females. Males approach calling females in a swaying flight with smooth turns. They typically land on the anterior portion of the host wasp's abdomen, and then step backward until they make contact with the cephalothorax of the female. As soon as their mesothoracic legs contact the female's cephalothorax, they curl around it, and the male initiates mating. Thereafter, the female fully retreats and never re-mates.

Of the ten superfamilies recognized in my classification of the Hymenoptera, all have been classified down to genera except the Ants, or superfamily IV, Formicoidea, a very large and most difficult complex, and rendered even more difficult by the extraordinary number and diversity of the sexes, there being sometimes several different forms to a single species.

Over 50 species of Cerambycidae have been reared on artificial diet, 17 of them from the egg. The method, which is described, has proved useful in reducing rearing time in the production of larvae and pupae for taxonomic purposes. It has also demonstrated the occurrence of diapause in some species of Cerambycidae. Other potentially fruitful lines of investigation, made feasible by this method, are suggested.

Developmental rates of post-diapause eggs of Diabrotica virgifera virgifera LeConte were compared in the laboratory at six constant temperatures, 12, 16, 20, 24, 28, and 32°C. Linear and nonlinear models were fitted to temperature versus developmental data and were used to predict egg hatch in the field. A four-parameter model fitted to median developmental rates (r2 = 0.99) indicated that development was linear between 16 and 28°C, optimal at 28°C, and decreased at 32°C. The lower development threshold (± SE) (10.5 ± 0.1°C) was determined by linear regression and the x-intercept method. Completion of post-diapause egg development required 258 ± 3 degree-days (± SE) above the base temperature. This compared well with the mean degree-days accumulated to 50% hatch (± SE) of 265 ± 24 which we observed in the field at several locations over 3 years using a degree-day model incorporating an 11°C developmental threshold and soil temperatures at 5- and 10-cm depths. A stochastic simulation model, incorporating a nonlinear developmental function dependant on soil temperatures taken every 2 h also predicted 50% hatch within 2 days. This model was validated in the field with 19 independent records of soil temperatures for several locations at two depths in the soil over 3 years. The simulation model accurately predicted time of 5 and 95% hatch, which indicates that this model has broad application in predicting the pattern of egg hatch for pest management.

The insect parasite Cotesia rubecula (Marshall) shows a long-day, photoperiodic response that results in diapause in the eonymph. Within the region of the critical photoperiod, the diapause response is modified by temperature and by the duration of the developmental period of the larval parasite, but in field populations in Vancouver, diapause is predominantly a response to short photoperiods. There is evidence that the parasite's response is largely independent of the host's response. Once diapause is induced, there is an obligatory dormant period of at least 2 months after which diapause terminates when specific-heat requirements are fulfilled. The estimated heat requirements are used to predict the date of diapause termination and the emergence of parasite adults in the field. Parasite activity begins almost 6 weeks after that of its host.

The critical photoperiod for populations in Vancouver, Canada, lies between 15- and 16-h photophase but in Canberra, Australia, the critical photoperiod is less than 13 h. The significance of this difference in the diapause response of the 2 introduced populations is discussed and recommendations are made for further biocontrol efforts.

Male genitalia of Choristoneura species from the Nearctic Region and Palaearctic Region are described and illustrated. The study revealed that the male genitalia are among the most important body parts that contain valuable morphological characters for species distinction or grouping in this genus. They are potentially useful in the clarification of the taxonomic status of species in closely related species groups, such as the spruce budworm species complex in North America.

On the basis of 17 interpretable male genital characters and their corresponding evolutionary states, the phylogeny of the genus Choristoneura is inferred and proposed. Nine species groups are recognized: (1) fumiferana, pinus, biennis, orae, occidentalis, lambertiana, carnana, retiniana, and spaldingiana; (2) diversana, murinana, metasequoiacola, and jezoensis; (3) longicellana; (4) lafauryana; (5) conflictana and fractivittana; (6) hebenstreitella, adumbratana, and luticostana; (7) albaniana and lapponana; (8) rosaceana and parallela; and (9) obsoletana and zapulata.

Morphological evidence obtained in the present study suggests that two conifer-feeding species groups of Choristoneura, species group 1 from the Nearctic Region and species group 2 from the Palaearctic Region, are related. They represent the least evolved species groups in the genus. Choristoneura rosaceana, C. parallela, C. obsoletana, and C. zapulata, representing some of the species feeding on deciduous trees, are among the most evolved Choristoneura species.

The western spruce budworm, Choiistoneura occidentalis Freeman, which normally passes through an obligate diapause in nature, was reared in the laboratory without diapause. The critical factor for preventing diapause appeared to be the physical environment presented to the first stage larvae. The response of C. occidentalis was flexible. The 2nd stage larvae could be made to diapause or forego diapause, depending on their rearing experience in the first stage. By eliminating diapause it was possible to rear about 7½ generations per year as against about 2¼ under normal diapause conditions. The diapause of the jack-pine budworm, C. pinus pinus Freeman, and C. lambertiana californica Powell, could be prevented by the same technique. The diapause of the spruce budworm, C. fumiferana (Clemens), could not be eliminated except after several generations of selection.

Two species of bees native to China, Osmia excavata Alfken and Osmia jacoti Cockerell, were released in 1991–1993 to observe life-history characteristics and assess pollination efficiency. Osmia excavata successfully established in both coastal (Shandong Province) and interior (Hebei Province) habitats, whereas O. jacoti was only able to establish in the coastal habitat. Sex ratios (female:male) ranged from 1:1.05 for O. jacoti to 1:2.46 for O. excavata. Apple, Malus domestica Borkh (Rosaceae), pollination was enhanced following the release of either species in orchards in Shandong. Fruit diameter increased following the release of either Osmia species in 'Red Delicious' blocks compared with control blocks where no pollination treatment was applied. The number of seeds per fruit was also increased relative to controls, and the percentage of asymmetrical fruit decreased. Release of O. excavata produced the best results for this cultivar. For 'Ralls Janet', the number of seeds per fruit increased following the release of either species and the percentage of asymmetrical apples decreased. Effects on fruit diameter were confounded by poor cultural practices (i.e., lack of adequate fruit thinning) in these 'Ralls Janet' blocks. Fruit set increased relative to controls following release of either Osmia species for both apple cultivars. Release of O. excavata also produced higher fruit set relative to blocks that received hand pollination treatment; release of O. jacoti was better than hand pollination only for 'Red Delicious'. Observations on the behaviour of individuals showed that O. excavata averaged 49.6 foraging trips per day and set an estimated 3108 fruit on 'Ralls Janet'; O. jacoti made fewer foraging trips (average of 31.2) per day and set 1831 fruit. Both species were more efficient pollinators than Apis mellifera. Osmia excavata would appear to be a better candidate for commercial apple pollination than O. jacoti under conditions similar to those in this study.