Cymodusopsis townesorum sp.nov. and C. nigricincta novomexicana ssp.nov. (Hymenoptera: Ichneumonidae) are described from the Nearctic region.

Baited tree experiments confirmed the hypothesis that frontalin is a multifunctional pheromone that can induce the mountain pine beetle, Dendroctonus ponderosae Hopkins, to aggregate on and mass-attack lodgepole pine, Pinus conforta var. latifolia Engelmann. A re-examination was undertaken of the role of four known semiochemicals, myrcene, trans-verbenol, exo-brevicomin, and frontalin, tested as tree baits alone (with the exception of myrcene) and in all possible combinations. There was considerable redundancy evident in the semiochemical signal. For example, myrcene + frontalin and trans-verbenol + exo-brevicomin induced attack on baited trees at similar levels of intensity. The results suggest that beetles of either sex could initiate a mass attack. During the most attractive phase of host colonization, redundancy in the semiochemical signal could act as a fail-safe mechanism to ensure perception of and response to odors from an attacked tree. In addition the standard, commercial, tree bait containing myrcene, trans-verbenol, and exo-brevicomin might be modified by deleting myrcene, making a more acceptable and cost-effective operational bait.

Trigonopeltastes thomasi sp.nov. from Sumidero Canyon National Park, Chiapas, Mexico, is described and figured. Unusual characters of the new species that relate to generic placement are discussed.

The mullein bug, Campylomma verbasci (Meyer) (Heteroptera: Miridae), was studied in and around 17 apple orchards in the Okanagan Valley during 1982–1984. Apple and pear were overwintering hosts and the principal perennial hosts during summer months. Campylomma verbasci was the most abundant mirid on apple and occurred in 16 orchards, with two or three generations per year. Nymphs first emerged from overwintered eggs near full bloom, but variation in timing occurred between orchards and years. Population densities of C. verbasci were higher (P<0.05) in unsprayed than in sprayed orchards, but no differences were observed between commercial and “organic” orchards. In June, some adults moved onto herbaceous plant hosts, primarily common mullein, Verbascum thapsus L. Two generations of C. verbasci were found on mullein and the bugs were distributed in an aggregated pattern. Significant associations occurred among height, raceme length, or flower number of mullein plants and the number of C. verbasci on them. From mid-August to October, adult numbers declined on mullein and increased on apple. The number of mullein plants per orchard was not always associated with the density of overwintered C. verbasci in the following year.

Deutonymphs, and male and female adults, of Stygameracarus cooki sp.nov., and a male adult of S. canadensis sp.nov., are described from interstitial habitats associated with small streams in temperate North America. The genus Stygameracarus and the monobasic subfamily Stygameracarinae are proposed and diagnosed, based primarily on the shape of the capitulum and the highly modified structure of the pedipalps in both deutonymphs and adults, and the distinctive structure of the genital field region in adults. Possible relationships between members of the new genus and other Athienemanniidae are discussed, and a new key to the subfamilies of Athienemanniidae is presented.

Interactions between Bacillus thuringiensis Berliner and Apanteles fumiferanae Viereck as mortality factors of the spruce budworm, Choristoneura fumiferana (Clemens), were investigated by placing parasitized and nonparasitized budworm larvae on foliage with and without spray deposits of a commercial formulation of B. thuringiensis. The effect of larval age (and, thus, the timing of spray applications) was examined by using peak third-instar and peak fourth-instar larvae. We demonstrated that parasitized larvae are more likely to survive exposure to B. thuringiensis because they feed less than non-parasitized larvae and are thus less likely to acquire a lethal dose of the bacterium. Bacillus thuringiensis nevertheless reduced parasitoid populations by 50–60% by killing their hosts before parasitoid emergence. This negative impact of B. thuringiensis on parasitoid survival was decreased when exposure of budworm larvae to spray deposits was delayed from peak third to peak fourth instar. The enhanced survival of parasitoids offset the lower mortality as a result of B. thuringiensis in the delayed sprays. We conclude that B. thuringiensis applied when budworm larval populations are at peak fourth instar or later would complement rather than interfere with the beneficial effects of A. fumiferanae. The implications for budworm management strategies are discussed.

In a survey of predaceous phytoseiid mites from 65 apple blocks in the Hood River Valley, Oregon, Metaseiulus occidentalis (Nesbitt) and Typhlodromus pyri Scheuten were the principal species present. Metaseiulus occidentalis predominated over T. pyri by a ratio of about 2:1 in 1984 mites collected during 1985. In experimental, commercial, and integrated pest management blocks, M. occidentalis was present alone or predominated over T. pyri in up to 88% of the blocks, whereas T. pyri occurred alone or predominated in up to 20% of the blocks. Both species occurred in near equal proportions in a maximum of 20% of blocks. An analysis of nine factors influencing the relative abundance of M. occidentalis and T. pyri indicated that vegetation in the habitat surrounding the block and the pesticides used were most important. In 1986, seasonal distributions and proportions of predatory mites found in individual blocks were similar to those found in 1985. The feasibility of managing mixed populations of T. pyri and M. occidentalis in Hood River orchards is discussed.

Six of the nine most common indigenous species of noctuid moths caught in a light trap at Glenlea, Man., over an 11-year period were univoltine and three were typically bivoltine but sometimes trivoltine. For the univoltine species, the day of peak catch and the day of 50% catch differed only by 3 days or less during 11 years. The timing of flight periods of Feltia jaculifera (Gn.), F. herilis (Grt.), Agrotis venerabilis Wlk., and Nephelodes minians Gn. were not influenced by the degree-days above 10 °C and the standard deviation of the date of 50% catch for these species was within 5–6 days. The date of 50% catch was more variable for Crymodes devastator (Brace) and Euxoa ochrogaster (Gn.), and the variation for the latter was partly explained by a relationship between flight dates and accumulated degree-days above 10 °C. For the multivoltine species, Pseudaletia unipuncta (Haw.), Discestra trifolii (Hufn.), and Xestia adela Franc., the day of peak catch for two generations also varied little from the day of 50% catch for each generation, but the day on which peaks occurred varied from year to year. Only for the first generation of D. trifolii was the day of 50% catch correlated with accumulated degree-days over 10 °C. Moth numbers for each species were not necessarily high when there were reports of crop damage by their respective larvae. There was no correlation between catches of moths in the first and second generation of multivoltine species, and there were no patterns of population trends among any of the economically important species. The life history, feeding habits, and economic importance of each species are discussed.

Descriptions and illustrations of structural features of adults, a key, and chorological data provide the basis for characterizing the genus Ozaena Olivier and classifying the 10 included species, two of which are new: O. maxi (type locality: Iracubo, CAYENNE), and O. manu (type locality: Manu National Park, Madre de Dios Province, PERU). With a geographical range that extends from ca. 30°S to 30°N in the New World, all species of Ozaena occur in cis-Andean South America, only two ranging farther north: O. dentipes Olivier, to Panama; and O. lemoulti Bänninger to southern Arizona, USA. A reconstructed phylogeny postulates the following: the genus Platycerozaena Bänninger as the sister-group of Ozaena, together these genera comprising the Ozaena genus-group; within Ozaena, the O. dentipes group as sister-taxon of the O. lemoulti + convexa groups; within the O. dentipes group, O. maxi as sister-taxon of O. linearis Bänninger + dentipes; within the O. lemoulti group, the sequence O. ecuadorica Bänn. (O. elavata Bänn. [O. lemoulti + martinezi Ogueta]); and within the O. convexa group, O. grossa Bänn. as sister-taxon of O. convexa Bänn. + manu. Character evolution involves losses, gains, and shifts, in about equal numbers. Convergence is relatively rare, involving only three of 35 characters. The predominant mode of character evolution is simple, with few examples of sequential changes sustained through several speciation events. Basic modifications in evolution of the ground-plan of the Ozaena genus-group include reduction or loss (for example, tactile sense organs, antennal cleaner of the fore tibia, and adhesive vestiture of the male fore tarsi), and enhancement or gain (for example, scale-like sensilla basiconica on pronotum and elytra, concentration of sensilla basiconica in groups on the antennomeres, particularly antennomere 11). Within Ozaena, many modifications to the antennae and mouthparts indicate the importance of these organs to evolution of the group.

Based on phylogenetic relationships and the distribution pattern of the extant species, a reconstructed geographical history of Ozaena postulates the following: first, a vicariance event in South America separating the ancestral stock of Ozaena into a northern vicar that gave rise to the O. dentipes group, and a southern vicar that gave rise to the O. lemoulti and convexa groups; followed by cycles of range expansion and contraction that allowed for differentiation of successive stocks of species. The temporal range for these speciation events is estimated to extend over a period of about 12 million years, or from the latter part of the Miocene epoch to the Recent. The most recent speciation events are estimated to be of Pliocene age.

Based on lack of differentiation of South American and Middle American representatives of O. dentipes and O. lemoulti respectively, and extent of range in Middle America, these two species are postulated to be relatively recent invaders of the latter area, with O. dentipes being the more recent to arrive.

An outbreak of western spruce bud worm, Choristoneura occidentalis Freeman, in the Blue Mountains of eastern Oregon, USA, was treated with helicopter-applied carbaryl. Effects on forest ants were determined from pre- and post-spray samples taken from replicated 0.75-ha sprayed and unsprayed plots. Arboreally foraging ants were sampled with sticky drop traps placed under trees. Ground-foraging ants were sampled from food-baited boards. During 8 weeks of sampling, 13 225 ants from seven genera and 19 species were collected. Seven species were known budworm predators. After spraying, ant species diversity decreased in sprayed plots. Post-spray foraging decreased in all plots, but the decrease was more rapid and pronounced in sprayed plots. Among ground-foragers, budworm predators were clearly affected by spraying. Arboreal foragers, nearly all budworm predators, showed a significantly lower foraging rate in sprayed plots. Varying effects on different species were noted. Overall ant foraging remained depressed for at least 6 weeks after spraying, long enough for budworm development to be completed. Reduced ant predation on sparse budworm populations after spraying may contribute to budworm resurgence.

The Nearctic species of the genus Homaspis Foerster, parasites of various species of sawflies on coniferous and deciduous trees and shrubs, were revised. There are 10 species of which seven were described as new. These were placed in three species groups as follows: the areolatus group including H. areolatus and H. petiolatus spp.nov.; the cristatus group including H. cristatus and H. pectinatus spp.nov.; and the interruptus group, including H. interruptus (Provancher), H. slossonae Cushman, H. brevis sp.nov., H. cephalciae sp.nov., H. albipes Davis, and H. cavatus sp.nov. Relationships of the species groups were discussed.

The abundance of nine stored-product species found in crop residues in farm granaries in the Prairie Provinces was influenced by farm practices, kinds of crops stored in the granaries, and the materials used in the construction of the granaries.

Some species were found more frequently than expected on farms where there had been previous infestations (Pyralis farinalis L.), or where there was livestock (Cryptolestes ferrugineus [Stephens]).

Fewer samples than expected were found infested with Cryptophagus varus (W. & C.), where insecticidal sprays were used, but more C. ferrugineus than expected were found where fumigants or insecticidal sprays were used.

Fewer samples of canola residues than expected contained insects, but barley residues contained more insects than expected.

Wooden granaries contained more insects than expected, except for C. ferrugineus.

Cole’s coefficient of association showed that some species were often associated but other pairs of species such as Tribolium audax Halstead and Lathridius minutus L. were negatively associated.

These relationships between species and their environments can be used to reduce the abundance of stored-products insects in farm granaries.

Variation in tree height, number of attacks by the Sitka spruce weevil (= white pine weevil) (Pissodes strobi [Peck]), tree form, and stem defect were studied in a 15-year-old Sitka spruce (Picea sitchensis [Bong.] Carr.) provenance test near Sayward, on Vancouver Island, B.C. An aggregated spatial distribution of the attacks was found in the plantation. Average number of attacks, tree form, and total tree height varied significantly among provenances and among families within provenances in both light and severe infestation patches. The number of unattacked trees varied by provenance from 5 to 51%, but in patches of severe infestation it varied from 0 to 64%. The number of attacks per tree had a significant negative effect on tree height. However, at the same level of attack, some provenances grew significantly taller than others. Thirty, 19, and 51% of all trees were classified as having a good, medium, or poor form, respectively. Among provenances located in severe infestation patches, the percentages of trees having good form varied from 4 to 64%. The type of defect that formed after an attack (minor crook, major crook, or fork) varied by provenance. Aggregated weevil attack and genetic differences among provenances may have accounted for this variation.

E-Myrcenol reduced catches of the pine engraver, Ips pini (Say), to ipsdienol-baited, multiple-funnel traps in a dose-dependent fashion. The sex ratio was unaffected by E-myrcenol treatments. Lures containing E-myrcenol in ethanol solution failed to protect freshly cut logs of lodgepole pine from attack by I. pini. Rather, I. pini preferentially attacked logs treated with devices releasing E-myrcenol and ethanol, over nontreated, control logs. Our results demonstrate that E-myrcenol is a new pheromone for I. pini, and emphasize the importance of understanding basic pheromone biology before utilisation of a semiochemical in forest pest management.

Diptychophora huixtla from Chiapas, Mexico, and Diptychophora powelli from Guerrero, Nayarit, and Oaxaca, Mexico, are described as new species. The two species can readily be distinguished from each other and from other Diptychophorini by their wing patterns and features of the genitalia.

Ips grandicollis (Eichhoff) was first recorded from Jamaica in 1978 and has become a potential pest in Pinus plantations in the island. Its distribution there is determined by the occurrence of suitable food, but not by altitude or rainfall. Developmental mortality due to predators, parasites, and resin did not limit population numbers within logs: control resulted ultimately from competition among egg-laying females and among larvae for space in suitable logs. However, when the entire Jamaican population was considered, dispersive loss of adults played a major part in the limitation of numbers. A cyclic budget revealed that a minimum of 44% of the population was lost during dispersal. Dispersive loss in the males (77.3%) was higher than that in the females (35.4%), and this difference may be related to the primary role of the males in finding suitable logs.

A new species, Colias johanseni, is described. This species has male androconia similar to Colias meadii Edwards, 1871, and many palaearctic, neotropical, and ethiopian species, but the wing pattern is generally similar to that of Colias hecla Lefèbvre, 1836. Thus far, it has been found only on dry tundra at Bernard Harbour, N.W.T., Canada.

The flea beetle, Phyllotreta striolata (F.), was attracted to the cruciferous plants Brassica oleracea L. and Raphanus sativus L., but not to B. campestris L. and B. napus L. which are important natural host plants, nor to Pisum sativum (L.), a legume. The presence or absence of attraction was demonstrated by exposing small groups of caged plants to natural populations and trapping beetles near the plants. In choice and no-choice laboratory feeding experiments, P. striolata fed on eight Cruciferae in the genera Brassica, Raphanus, and Sinapis but not on P. sativum. Phyllotreta striolata fed less on S. arvensis L. and S. alba L. than on plants in the other genera. Within Brassica, B. oleracea, B. napus, and B. campestris were preferred over B. juncea (L.) Czern and B. nigra (L.) Koch. Discrimination at the attraction phase of host selection did not account for discrimination shown in laboratory feeding experiments nor in the natural attack of flea beetles on cruciferous crops.

The black fly species Simulium luggeri Nicholson and Mickel s.l., S. vittatum Zetterstedt s.l., S. venustum Say s.l., S. verecundum Stone and Jamnback s.l., and S. decorum Walker s.l. were collected in silhouette traps near Prince Albert, Sask., in 1986, and near Choiceland, Sask., from 1986 to 1988. The Prince Albert site was located between and within 2 km of the North and South branches of the Saskatchewan River and was 25 and 60 km south of the Whitefox River and Torch River systems. The Choiceland site, 60 km east of the Prince Albert site, was 15 km north of the main branch of the Saskatchewan River and 1/2 and 25 km south of the Whitefox River and Torch River, respectively. Simulium luggeri was the most abundant species collected at the Prince Albert site whereas S. luggeri, S. vittatum, and the S. venustumlverecundum complex were approximately equally abundant in trap catches near Choiceland over the entire season but in each study year a seasonal progression in peak abundance occurred. Black fly numbers in sweep net collections taken once, in the middle of the day, were weakly correlated with numbers in silhouette trap collections taken during an entire day.

The southern pine beetle, Dendroctonus frontalis Zimmermann, was studied in the laboratory to determine the influence of associated fungi on its reproduction. First-generation (P) surface-sterilized beetles associated with mycangial fungi (Ceratocystis minor [Hedgecock] Hunt var. barrasii Taylor or SJB 122) constructed more galleries and laid more eggs, at faster rates, than P beetles not associated with these mycangial fungi. No significant differences occurred among non-surface-sterilized P beetles associated with the phoretic blue staining fungus Ceratocystis minor (Hedgecock) Hunt and mycangial fungi or among progeny of P beetles (F1 generation) carrying mycangial fungi. P and F1 surface-sterilized beetles produced more eggs at a greater density than non-surface-sterilized beetles associated with blue stain, but gallery length and the rate of construction were not different. P and F1 surface-sterilized beetles laid more eggs and constructed galleries faster than surface-sterilized beetles that carried no mycangial fungi. The re-emergence rate of beetles was fastest for P beetles associated with C. minor and significantly slower for fungus-free P beetles, P beetles carrying only mycangial fungi, and F1 beetles, respectively. The F1 generation emerged fastest when associated with both mycangial fungi and slowest when associated with SJB 122, and C. minor var. barrasii or no fungus, respectively. This study employed a successful new rearing technique for isolating specific southern pine beetle/fungal associations.