Rhinocyllus conicus Froelich was introduced into Wyoming in 1975 for the biological control of musk thistle, Carduus nutans L. A survey of 15 release sites was conducted in 1986 to determine parasitism of R. conicus. Eight species of parasitic Hymenoptera were identified. Parasitism of R. conicus infecting the flower heads of musk thistle was low (0.6%), but greater for weevils within the peduncles (17%). Parasitism varied among release sites, ranging from 0.0 to 1.3%, but was not significantly correlated with the duration of weevil establishment.

Analysis of structural features of adults (legs, proportions of prothorax, male genitalia, and ovipositor) establishes the hypothesis that Anisocnemus Chaudoir, Trichopselaphus Chaudoir, and Stenomorphus Dejean comprise a monophyletic assemblage, named the Stenomorphus genus-group, with Anisocnemus the adelphotaxon of Trichopselaphus + Stenomorphus. Analysis of form of median lobe, armature of the internal sac, allometric trends in proportions of the prothorax and hind tibia, and chorological considerations, provide the basis for recognition of six species of Stenomorphus and postulation of their phylogenetic relationships, as follows: S. convexior Notman {[S. penicillatus Darlington + S. sinaloae Darlington] + [S. cubanus Darlington + (S. angustatus Dejean + S. californicus Ménétries)]}. Three monophyletic species-groups are recognized: S. convexior, including S. convexior; S. sinaloae, including S. penicillatus and S. sinaloae; and S. angustatus, including S. cubanus, S. angustatus, and S. californicus. The names Stenomorphus dentifemoratus Chaudoir, 1844 and Stenomorphus alius Darlington, 1936 are synonymized, and S. dentifemoratus Darlington, 1936 (not Chaudoir) is renamed S. darlingtoni. Morphometric and chorological features provide evidence for subspecific recognition, each taxon representing a new combination: for S. angustatus, S. a. angustatus, S. a. braziliensis Darlington, and S. a. dentifemoratus Chaudoir; for S. californicus, S. c. californicus, S. c. rufipes LeConte, S. c. manni Darlington, and S. c. darlingtoni Ball and Shpeley. Evolutionary trends postulated include development of allometry with respect to form of the prothorax and hind tibiae, correlated with sexual dimorphism. Driving forces are postulated to be associated with sexual selection and burrowing. The geographical history of Stenomorphus is reconstructed as follows, using the reconstructed phylogeny and chorological affinities interpreted against a background of geological and climatic events in Middle America, during the Late Cretaceous, and Tertiary and Quaternary Epochs: isolation in Middle America from its South American adelphotaxon of the ancestral stock of Stenomorphus; specialization for life in drier tropical forests and savannas; isolation and differentiation of taxa in response to cyclical climatic changes and mountain building; and over-water dispersal to, and isolation and differentiation in, the Greater Antilles. A key, figures of diagnostic features, descriptions of structural features and of geographical ranges (supplemented with maps) provide means of recognition of taxa.

Intra- and inter-plant spatial patterns were determined for adult and immature western flower thrips, Frankliniella occidentalis (Pergande), on greenhouse sweet pepper at two commercial greenhouses using five sampling methods. The population density of the thrips was monitored biweekly for 4 months from May to August using blue sticky-traps, plant tappings, blossoms, plant leaves, and whole plants. The intra-plant spatial patterns of adult and immature populations of F. occidentalis were aggregated with the majority of the thrips collected from the top one-third of the plant. The inter-plant spatial patterns also were aggregated. The aggregation cluster for the adult thrips was at least three plants in size, although it was surmised to be at the individual plant level for immature F. occidentalis. The accuracy of the blue sticky-trap, plant tapping, blossom, and leaf samples was determined for monitoring the population densities of adult and immature thrips throughout the growing season. It was shown that leaves should be sampled from the middle section of the sweet pepper plant when using this sampling method. A precision-level sampling program was proposed for monitoring adult F. occidentalis on greenhouse sweet pepper. Sampling blossoms was the most cost-effective sampling method based upon time and number of samples for a specific precision level.

Metzneria paucipunctella Zeller is a seed head moth introduced for biological control of spotted knapweed, Centaurea maculosa Lamarck, in the Pacific Northwest. A cage study was conducted in Montana in 1987 and 1988 to assess the feeding strategy of the M. paucipunctella larva and its impact on two seed head flies, Urophora spp., also introduced on spotted knapweed. Each moth larva destroyed an average of 8.13 knapweed seeds. Most of the seeds were destroyed prior to seed dispersal in early September but the remaining seeds were attacked in the spring of the following year. Each larva tied an average of 7.0 seeds with silk webbing which allowed for feeding long after normal seed dispersal. Seed survival in cages containing both the moth and the two fly species (4.71 seeds per head) was significantly less than in fly-only cages (9.75 seeds per head). The moth larvae caused extensive mortality to the two Urophora species, especially during the spring months. Moth-caused mortality to U. affinis larvae increased from 19% during June through October to 67% in May of the following year. Mortality to U. quadrifasciata also occurred but did not increase significantly in the spring. Data from 10 field sites showed very little association between M. paucipunctella and the two Urophora species which suggests that the unnatural conditions associated with the cages did not increase the incidence of joint moth and fly attack to individual seed heads. The moth is a valuable biocontrol agent as it is contributing significantly to the overall consumer pressure on spotted knapweed seed heads.

Fourteen new species of the family Pauropodidae are described from central Japan: Allopauropus (Allopauropus) loligoformis. A. (Decapauropus) fortisus, A. (D.) ibarakiensis, A. (D.) infurcatus, A. (D.) ligulosus, A. (D.) pseudokoreanus, A. (D.) tetraramosus, A. (D.) toshiyukii, A. (D.) yamizo, Pauropus tamurai, Stylopauropus (Stylopauropus) canaliculatus, S. (Donzelotauropus) peniculatus, S. (D.) undulatus, and Colinauropus schelleri. Among them, two genera, Stylopauropus and Colinauropus, are recorded for the first time from Japan.

All larval instars of Compsilura concinnata (Meigan) (Diptera: Tachinidae) develop in the midgut of the gypsy moth [Lymantria dispar (L.) (Lepidoptera: Lymantriidae)] between the peritrophic membrane and gut wall. Parasitoid larvae placed artificially in the host haemocoel quickly moved to this characteristic position. There was a positive relationship between parasitoid size, as measured by the weight of the puparium, and the potential fecundity of female flies. When C. concinnata parasitized third-instar larval hosts, there were fewer successful multiple emergences, parasitoid larvae took longer to develop, and puparia were significantly smaller than those of parasitoids attacking fifth-instar hosts.

Gypsy moth larvae grew more slowly on diets supplemented with 0.5 and 2.5% tannic acid than on non-supplemented diets. Similarly, C. concinnata females were smaller (with associated reduction in fecundity) when emerging from hosts feeding on the tannin diets than when hosts were feeding on control diets. The effect of tannic acid on the parasitoid was indirect and was the result of a reduction in host quality on the tannin diets. Reduction in parasitoid fecundity associated with tritropic interactions (among the host plant, the gypsy moth, and the parasitoid) may provide a possible explanation for the irregular impact of C. concinnata on gypsy moth populations.

Evidence for a female-produced sex pheromone in the white pine cone beetle, Conophthorus coniperda (Schwarz), and the red pine cone beetle, C. resinosae Hopkins, was obtained from laboratory bioassays and field experiments conducted with C. coniperda beetles from Ontario and North Carolina. In an olfactometer, males from both species responded significantly more to volatiles from females than to volatiles from males or cones. Generally, females did not differ in their response to female-, male-, or cone-produced volatiles. Both sexes responded to host volatiles. The strong response by male C. coniperda to females was confirmed in field tests.

Sixteen species of parasitoids were found attacking outbreak and collapsing populations of the jack pine budworm, Choristoneura pinus pinus Free. (Lepidoptera: Tortricidae), in several plots in northeastern and northwestern Ontario. The patterns of parasitism were similar among widely separated plots with only a few species consistently dominating the parasitoid fauna. The greatest difference in the pattern of parasitism was between sustained and collapsing infestations. Collapsing populations of jack pine bud-worm were associated with relatively high levels of parasitism by Meteorus trachynotus Vier. (Hymenoptera: Braconidae) and Lypha setifacies (West.) (Diptera: Tachinidae) which attacked the late larval stages of the budworm. The results are discussed in comparison with other jack pine budworm studies and with spruce budworm population studies.

Adult female Tarsonemus ascitus Delfinado mites are recorded for the first time as phoretic on the grain-inhabiting lathridiid beetles Cartodere constricta (Gyllenhal) and Enicmus fictus Fall, and the rhizophagid beetle Monotoma picipes Herbst. The mites preferred to attach to the lateral and undersides of the prothorax of the beetles. The spatial distribution of T. ascitus on C. constricta in suction traps was determined as a guide to the numbers of beetles that would have to be collected to obtain reliable estimates of numbers of mites found per beetle. The mean numbers of mites per beetle was always smaller than the variance, and the spatial distribution of the mites followed a negative binomial distribution. The numbers of beetles required to be collected to provide a predetermined measure of the precision of the numbers of mites per beetle were calculated.

Temperature-dependent development of the egg, larval, and pupal life-stages of the mountain pine beetle (Dendroctonus ponderosae Hopkins) was described using data from constant-temperature laboratory experiments. A phenology model describing the effect of temperature on the temporal distribution of the life-stages was developed using these data. Phloem temperatures recorded in a beetle-infested lodgepole pine (Pinus contorta Douglas) were used as input to run the model. Results from model simulations suggest that inherent temperature thresholds in each life-stage help to synchronize population dynamics with seasonal climatic changes. This basic phenological information and the developed model will facilitate both research and management endeavors aimed at reducing losses in lodgepole pine stands caused by mountain pine beetle infestations.

Parasitoid species attacking sparse, endemic populations of Choristoneura occidentalis Freeman and C. retiniana (Walsingham) are reported from 2 years of host collections at seven sites across southern Oregon. Results are compared with rearings from epidemic populations either from the same region or the same plot. Collections were designed to allow quantitative estimation of host density. Most of the parasitoid species present during epidemics across North America were recovered from the endemic and epidemic populations studied. The major difference is that at endemic host densities Glypta fumiferanae (Viereck) (Ichneumonidae) is rare to absent, whereas ichneumonids of the tribe Campoplegini, especially Tranosema (= Diadegma) interruptum (Ashmead), are common. This is the reverse of the situation at epidemic densities and consistent with results reported from eastern North America. It is suggested that the observed shift in the parasite complex with budworm density has the potential for predicting population trends.

The recognition of four taxa within the calligraphus species group of the genus Ips DeGeer is supported by breeding experiments, karyology, morphology, ecology, and distributions. Ips calligraphus calligraphus (Germar) occurs in the eastern United States and adjacent parts of Canada. Ips c. ponderosae (Swaine) occurs in the range of Pinus ponderosa in the Black Hills, eastern Rocky Mountains, and in the northern Sierra Madre Oriental in Mexico. Ips c. interstitialis (Eichhoff) occurs in the Caribbean Archipelago but the homogeneity of populations on the islands of Hispaniola and Jamaica and the true type locality are uncertain. Ips apache Lanier infests various pines (excluding pinyon pines) at lower altitudes from southeastern Arizona through Mexico. Populations south of the Isthmus of Tehuantepec in Caribbean pines on the east coast of Central America are provisionally considered to be I. apache. Pairings of female I. calligraphus subspecies with male I. apache were infertile. Reciprocal pairing produced rare, sterile hybrids. Fertility of I. calligraphus subspecies was normal when I. c. calligraphus was the female but reduced when the female was either I. c. ponderosae or I. c. interstitialis. All members of the group had 15 pairs of autosomes plus a sex bivalent (2n = 32) that assumed a “parachute” configuration to give a male meiotic formula of 15 AA + Xyp. Second meiosis chromosomes of I. apache lack some of the heterochromatic arms present in I. calligraphus. Meiotic divisions of rare interspecific hybrids (I. apache ♀ × I. calligraphus s. lato ♂) had numerous autosomal rearrangements, a possible translocation, and oversized (probably tetraploid) spermatozoa. Meiosis was mostly normal in intersubspecific hybrids, but the presence of occasional anaphase bridges or nonmigrating chromosomes and alignment of pachytene homologs revealed inversions and other possible rearrangements. Univariate and multivariate analyses of pars stridens strial width, pronotal width, and male genitalia revealed significant differences among all four taxa.

Coleophora deauratella Lienig and Zeller is reported for the first time in North America. This casebearer species was introduced accidentally from Europe almost 30 years ago but remained unrecognized. It currently is known from eastern Canada and northeastern United States. Larvae feed on seeds of red clover, Trifolium pratense L. Diagnostic characters of the larval case and the adult, as well as features separating C. deauratella from two similar casebearer species, are presented.

A new genus and species, Sacculozetes filosus, is described from riparian grassland in the Soviet Far East, and a new species, Guatemalozetes danos, is described from shortgrass and alpine prairie in western North America, both on the basis of adults. The genus Guatemalozetes Mahunka is redefined; this is the first record of this genus from temperate North America. A close relationship is indicated between Sacculozetes and Lamellobates Hammer, Paralamellobates Bhaduri and Raychaudhuri, and Hypozetes Balogh. The uncertain family placement of Sacculozetes and Guatemalozetes within the Ceratozetoidea is discussed. Adults of both genera exhibit character states of the Mycobatidae, but until immatures are discovered, they are considered unplaced genera in the superfamily.

A European microphysid, Loricula bipunctata (Perris), is reported as new to the Nearctic Region. The only other member of the genus recorded from North America, the Palearctic L. pselaphiformis Curtis, also is adventive in our fauna (Kelton 1980)

Many cone and seed insects exhibit a dormancy in which the individuals may undergo a diapause that lasts 1, 2, or more winters and the proportion of 1-year diapause (1YD) and 2-year diapause (2YD) varies from year to year (Hedlin et al. 1980). Thus, segregating the two diapause types carries a practical importance for forecasting the attacking adult population in a given year. Based primarily on teleological reasoning it has been argued that insects committed to a longer dormancy may have higher weights with metabolites to sustain survival for a longer period. Individual weights have been examined with the hope of separating 1YD from 2YD individuals.