A new species, Contarinia brassicola Sinclair (Diptera: Cecidomyiidae), which induces flower galls on canola (Brassica napus Linnaeus and Brassica rapa Linnaeus (Brassicaceae)), is described from Saskatchewan and Alberta, Canada. Larvae develop in the flowers of canola, which causes swelling and prevents opening, pod formation, and seed set. Mature larvae exit the galls, fall to the soil, and form cocoons. Depending on conditions, larvae will either pupate and eclose in the same calendar year or enter facultative diapause and emerge the following year. At least two generations of C. brassicola occur each year. Adults emerge from overwintering cocoons in the spring and lay eggs on developing canola flower buds. The galls produced by C. brassicola were previously attributed to the swede midge, Contarinia nasturtii (Kieffer) in Saskatchewan; here, we compare and list several characters to differentiate the two species.

The oribatid mite genus Megeremaeus is redefined, with the addition of information on leg chaetotaxy and immature instars. Three new species are described, Megeremaeus hylaius from northeastern North America, and M. keewatin and M. kootenai from northwestern North America. Descriptions of the former two species are based on adults and immatures, the latter species on adults only. Nymphs of M. montanus Higgins and Woolley are described. A key is given for the six known species in the genus.

Inferences regarding the value of Nasonia vitripennis in the natural control of Musca domestica based on laboratory research should consider the general absence of this parasite on that host in nature. Predominant natural parasites of M. domestica are listed.

Neodiprion sawflies are economic pests in pine plantations in eastern and southern United States and eastern Canada. While not a serious problem in California at the present time, they will probably become so with the advent of more intensive forest management.

Little is known of the species present in California. The only specific study was that concerned with the Neodiprion abietis complex on white fir in 1952 (Struble, 1957). Miscellaneous data are available from the survey records of the Pacific Southwest Forest and Range Experiment Station, Berkeley.

A new species of the genus Plusia Ochsenheimer is described from North America on the basis of differences in wing colour, markings, and genital structure. The new species, typically found in bogs, was first recognized through molecular sampling for the Barcode of Life Initiative and differs significantly from other species of Plusia in the cytochrome c oxydase I (COI) mitochondrial gene sequence.

In an attempt to control the spruce budworm in northwestern Ontario, Sumithion and Phosphamidon were sprayed from the air in June 1968. Some carabid beetles and one spider were studied to assess the effect the insecticides had on forest floor arthropods in mixed boreal forest. A sudden decrease in collected specimens both in and out of the spray area 1 week prior to spraying was probably due to reduced activity caused by heavy rainfall, but during and following the spray period there were fewer specimens collected in the spray area than in the control area.

Parasitism of Hyphantria cunea Drury was measured over a 17-year period in a series of permanent study areas in New Brunswick and Nova Scotia. The percentage of colonies attacked by parasites was independent of both plant host and colony size, but the percentage of larvae attacked within colonies decreased in the larger colonies. For most parasite species the percentage of larvae attacked per colony was relatively constant, regardless of the percentage of the colonies attacked in any area or year. Thus the colonial habit of H. cunea imposes a limit on the overall degree of parasitism that can be achieved by most of the parasite species.

The mycetophilid Macrocera nobilis Johnson, previously known only from forests in New Hampshire and Massachusetts, is here reported from caves in Oklahoma, Missouri, Kentucky, Tennessee, and West Virginia. A study of populations in Oklahoma shows that the short-lived adults mate in cave entrances, but that oviposition, larval development, and pupation occur only in the dark zone of caves. The larvae build extensive webs upon which they travel and which they use to capture insect prey (mostly other Diptera). Reproduction and life cycle development is not seasonal. The larval stage lasts 9 or 10 months, and the pupal stage about 2 weeks.

The life cycle of Ironoquia punctatissima (Walker) is described for a population occurring in a temporary stream in southern Ontario. A description of the hitherto undiscovered pupa is also given.

The predatory behavior of Lonchaea corticis Taylor on the white pine weevil, Pissodes strobi Peck, in Sitka spruce, Picea sitchensis (Bong.) Carr., was studied by temporal sampling and dissection of terminal leaders, and by laboratory experiments. L. corticis oviposition occurred when mining P. strobi larvae were consolidating the feeding ring, an event that segregates the weevil larvae into healthy front-feeders and weak, starving "followers." The number of L. corticis within a Sitka spruce terminal was highly correlated with the number of weak and dying P. strobi larvae, but not with healthy larvae.

L. corticis larvae experimentally deprived of dead P. strobi larvae, behaved as an effective predator, consuming both weak P. strobi larvae and healthy pupae, but apparently not healthy larvae. The transition of L. corticis from second to third instar appeared to occur only after sufficient weevils had been consumed. When an excess of prey was present, L. corticis larvae consumed a mean of 2.9 P. strobi pupae over their entire life cycle. In choice experiments, L. corticis larvae searched for and located mining P. strobi larvae, and fed preferentially on P. strobi pupae rather than granary weevil pupae, Sitophilus granarius L. Under certain circumstances, L. corticis could be an important regulatory agent of P. strobi populations.

The effectiveness of topical applications of the juvenile hormone analog Fenoxycarb against selected developmental stages of the eastern spruce budworm, Choristoneura fumiferana (Clemens), was determined. Eggs at an early stage of embryogenesis (0–24 h old) were prevented from hatching and were more sensitive to the compound than older eggs (48–72 h old) and larval stages. Fifth-instar larvae displayed lethal morphogenetic effects following Fenoxycarb treatment, but third-instar larvae were refractory. Adult females constituted the most sensitive stage; treated insects laid eggs that failed to hatch. Untreated adult females that mated with Fenoxycarb-treated males also laid infertile eggs.

The eggs and larvae of Cryptocephalus quadruplex Newman and C. venustus Fabricius are described and illustrated. Both species very likely overwinter in the larval stage. The adults emerge from the last week of May to mid-June. Before mating they feed on plants for about a week. The oviposition period is quite extended and lasts from mid-June to the end of July. The eggs are laid singly in the leaf litter. The hatching period was 10–15 days in the laboratory. The larvae develop through 5 instars and feed exclusively on dead or decaying leaves of various plants. By the end of September most of them have grown to the 4th instar, some to the 5th. At this moment they stop feeding and move deeper in the leaf litter for overwintering. The 1st instar is easily recognized by the presence of the egg bursters on meso- and metathorax, the large flattened-papillate setae of the head capsule, and the presence of 2 pairs of spiniform setae on tibiae. In the following instars the size varies as well as the number of spiniform setae on the tibiae and the number of secondary clubbed setae on the pronotum.

Triarthria setipennis is a tachinid parasitoid of the European earwig (Forficula auricularia) and following introduction from Europe has become established in British Columbia and Newfoundland, where it provides low levels of control. Populations of T. setipennis were surveyed in central Europe during 1989–1991 and individual insects reared to identify available biotypes that may be more effective than biotypes already established in Canada. Additional information is provided on parasitoid biology; this could facilitate new introduction of T. setipennis which could be used to augment existing or introduced populations in Canada for the control of F. auricularia. Microclimatic conditions and sufficient territory space for pairs are important to elicit mating activity. Older males mated readily with newly emerged females. The gestation period of mated females is on average 19 days. Triarthria setipennis is ovolarviparous and lays its eggs close to potential hosts. Chemicals are involved in the host-finding and host-acceptance response of the females. Females lay on average 235 eggs. The oviposition period lasts 4–5 days. Once a first-instar larva contacted a host, it mounted it and tried to penetrate through the intersegmental skin between the head and thorax, or on the thorax or abdomen; this process takes less than 3 min. Only 16.7% of the parasitoids manage to penetrate the host successfully. The duration of larval development is variable, taking from 2 weeks to 2 months during June and July. Most pupae were obtained during August. Overwintering occurs in the pupal stage. In Germany and in the northwestern part of Switzerland there is one full and a partial second generation per year. The first generation of T. setipennis in southern Austria shows a long emergence period and the individuals differ markedly in colour. The highest rate of parasitism in the field was 46.9%.

Developmental time of Brevicoryne brassicae (L.) was measured in the laboratory at 8°, 13°, 18°, and 23 °C. Time from birth to adult was 126 degree-days above a threshold of 6.7 °C (°D6.7). Age-specific fecundity and longevity was measured at 13°, 18°, and 23 °C. The temperature thresholds for birth and physiological death rates were not significantly different from 6.7 °C. Fecundity averaged 40.7 nymphs/female and did not vary with temperature or frequency of removal of nymphs. Peak reproduction occurred 75°D6.7 after the molt to adult. Although the time of peak reproduction did not vary as a function of fecundity, height of the reproductive peak and length of the reproductive period did, but not in a 1:1 proportion. Age-specific fecundity was described as a polynomial function of aphid age in °D6.7 and fecundity. Longevity did not vary as a function of fecundity. All aphids survived until after the reproductive peak, so the sum of the age-specific fecundities very nearly equaled the net reproductive rate. Measurements of developmental time, fecundity, and longevity of B. brassicae in the field were 1.3, 0.66, and 1.2 times the respective laboratory value. Consecutive measurements of developmental time and fecundity showed that the former increased and the latter decreased during the season. The consequences of variable developmental time, fecundity, and age-specific reproductive pattern to the quantitative representation of population growth rates are discussed.

In this second paper on the North American Proctotrupidœ, I have taken up the sub-family Platygasterinœ, comprising, for the most part, small black species, all parasitic in larvæxs belonging to the Dipterous families Cecidomyiidœ and Tipulidœ.

It will be seen that I have recognized in our fauna species in all of the described genera but Iphetrachelus Haliday, and one new genus parasitic on Cecidomyious hickory galls.

Eighty Engelmann spruce logs (Picea engelmannii Parry), which were distributed in open (bulldozed to clearcut), semi-open (selectively cut), and dense (uncut) spruce forest, were infested with Dendroctonus obesus (Mann.) and Ips pilifrons Sw. and fed upon by northern three-toed and hairy woodpeckers. Sections of the infested boles were covered with screen to prevent woodpecker feeding and all logs were left in the field over one winter and through the following summer. By spring, the spruce beetle brood was reduced approximately 50% in all three forest areas. By fall, the spruce beetle brood suffered a 71, 83 and 52% reduction in the open, semi-open and dense forest, respectively. Spruce beetles appeared to be in greatest numbers in the semi-open forest, resulting in the greatest woodpecker predation there. Woodpeckers did not feed in the open meadows. Estimates in the spring, before the Ips emerged from the logs, showed that woodpeckers reduced the Ips brood by 76 and 11% in the open and semi-open forest, respectively. Ips were not found in dense forest or in meadows.

Dusky wireworms, Agriotes obscurus (L.), aggregated in similar numbers at wheat [Triticum aestivum L. (Gramineae) ‘Max’], oat [Avena sativa L. (Gramineae) ‘Walderen’], barley [Hordeum vulgare L. (Gramineae) ‘Verdin’], and fall rye [Secale cereale L. (Gramineae) ‘Wheeler’ and ‘Prima’] cultivar bait stations containing 100 seeds planted 3 cm deep in 127-cm2 circular bait stations. Similar levels of aggregation also occurred at 11 varieties of wheat planted at 100 seeds/127 cm2. When wheat, oat, barley, and the fall rye cultivars were planted at increasing density (0–180 seeds per bait station), aggregation by A. obscurus increased initially, but reached a plateau at numbers and at seeding rates specific to each grain variety as determined using the asymptotic equation y = B0(1 – e–B1x). Except for barley, this equation predicted wireworm densities within 11% of the densities actually observed at bait stations with 100 seeds/127 cm2. It was concluded that any of the wheat, oat, barley, or fall rye varieties would be suitable for monitoring A. obscurus wireworm populations if planted in bait stations at 100 seeds/127 cm2, as well as for aggregating wireworms by means of a trap crop.

Three mirids, Diaphnidia pellucida Uhler, Hyaliodes harti Knight, and Campylomma verbasci (Meyer), are effective predators of the red mite and probably of the clover mite from early in June until the latter part of July. These three species are the only important predacious mirids under the conditions of the present spray practices in Nova Scotia. Gilliatt (2) has given an account of the life-histories of the three specics and discussed their importance in the natural contrnl of the red mite, and his account need not be repeated here. The three mirids are often the only important predacious species in many commercial orchards during the summer months because of the destruction of I. tiliae and H. faurei by the sulphur sprays emploved around the bloom period. Their presence in such orchards is in itself evidence that neither bordeaux mixture nor flotation sulphur reduces their numbers. Observation on a considerable number of occasions showed that iron carbamate has no effect on these mirids. An opportunity to test some of the common spray chemicals on two of the species was presented in the F. Palmer orchard at Berwick in 1947. Two trees were sprayed with each of the materials listed, and the insects were collected as they dropped on two trays, of 32 square feet each, which had been placed beneath the trees.

Genetic variation among western spruce budworms from 14 sites of high-density infestation in central Idaho and western Montana was examined using electrophoresis. Relationships were assessed through cluster analysis of genetic distance values and by study of shared rare alleles. Three genetically similar groupings appeared among budworms over the 14 sites. The genetic data and analysis of historical records of outbreaks over the area indicate that dispersal may play a significant role in the spread of some infestations.