Juvenile Monterey pines, Pinus radiata D. Don (Pinaceae), in a native stand on the Monterey Peninsula, California, exhibited wilted green shoots in the spring of 1996. The pitch canker fungus, Fusarium subglutinans (Wollenweb. & Reinking) P.E. Nelson, Toussoun & Marasas f.sp. pini, was subsequently isolated from 95% of these shoots. Spittle masses produced by Aphrophora canadensis Walley were observed on the symptomless shoots of many of these trees. The pitch canker fungus was isolated from the feeding sites of this insect on 55% of symptomless shoots, and from shoot sections adjacent to these feeding sites on 29% of the shoots. Shoots with spittlebugs feeding on them in May 1996 were more likely to develop pitch canker disease by September 1996 and March 1997 than shoots without spittlebugs. Shoots with spittle masses in March 1997 were as likely to develop pitch canker disease by May and August 1997 as shoots without spittle masses, but the origin of the infection was most likely where A. canadensis feeding had taken place. In a controlled test, the incidence of pitch canker on shoots of potted Monterey pines was dependent on the presence of a spittlebug and a spore suspension of the pathogen. Thus, both field observations and controlled studies show an association between native A. canadensis and the introduced pitch canker pathogen. The role of A. canadensis in the epidemiology of pitch canker disease remains to be determined.

The Colenis of the United States and Canada are reviewed. Three new species are described: Colenis (Colenis) bifida n.sp., Colenis (Colenis) stephani n.sp., and Colenis (Colenis) ora n.sp. The Colenis subgenus name Carcharodes Hlisnikovsky is preoccupied: Colenodes is proposed as a replacement name.

Observations of apple blotch leafminer moths, Phyllonorycter crataegella (Clemens), during daylight hours in commercial apple orchards in New England from 1982 through 1984 indicated a diurnal pattern of activity. Substantial flight in the morning, almost exclusively by males, was associated with mating, and lesser flight from midafternoon until darkness, predominantly by females, was associated with oviposition. Moths were comparatively inactive during midday hours, at which time they were located primarily on the lower third of the tree trunk during the first moth flight (overwintering generation moths), and on leaves during the second and third moth flights (first and second generation moths, respectively). Moths were concentrated at the inner half of the tree canopy during all three moth flights, and especially below 1.5 m height during the first moth flight.

All ontogenetic stases of the yew big bud mite, Cecidophyopsis psilaspis (Nalepa), from British Columbia were studied by scanning electron and light microscopy and were compared with an English population of this species. The species was redescribed from the two populations, which were found to be quite similar in general appearance and in most of the morphometric data analyzed. Spermatophores in this species are similar to those observed in other Eriophyoidea. Details of a male spermatophoric organ are described and illustrated for the first time in an eriophyoid mite. Moulting in C. psilaspis is shown to be prodehiscent. The data reported here neither support nor reject the alternative hypothesis that the first active stase is larval versus nymphal. However, to account for the ontogenetic evidence, the first active stase is herein considered larval.

The North American genus Ceratagallia Kirkaldy, 1907 is redefined to include subgenus Aceratagallia Kirkaldy, 1907 (= Ionia Ball, 1933, syn.nov.) with 78 species in two subgenera. Two additional new species are unplaced to subgenus: C. acerata from Oregon, and C. emarginata from Mexico. The typical subgenus Ceratagallia has 30 species, including C. gillettei (Osborn & Ball, comb.nov.), C. sordida (Oman, comb.nov.), and two new species C. ana from Mexico and C. vipera from Washington state. Subgenus Aceratagallia has 46 species, all new combinations under Ceratagallia. The economic "species" formerly known as "sanguinolenta" is divided into the Canadian clover leafhopper C. humilis (Oman) and the American clover leafhopper C. agricola sp.nov. Other new taxa in subgenus Aceratagallia include 18 new species and seven new subspecies: alaskana (ssp. of siccifolia) from Alaska; omani on the Pacific coast from Oregon to British Columbia; clino and lophia from the Oregon interior; compressa (ssp. of siccifolia), gallus, modesta, okanagana, and zacki (ssp. of nanella) from intermontane valleys of the Pacific northwest and southwestern mountains; interior (ssp. of humilis) and rossi from the Sonoran subregion; australis (ssp. of nanella), coma, ebena, entoma, falcata, oionus, and venosa from Mexico and Texas; alvarana (ssp. of humilis), cerea, cristula, harrisi, semiarida, and viator widespread between the Appalachian and Rocky Mountains; and whitcombi (ssp. of robusta) from Florida to Arizona. Four former species are reduced to subspecies: compacta Oman and poudris Oman in C. robusta (Oman), helveola Oman in C. cinerea (Osborn & Ball), and truncata Oman in C. humilis. The taxa are keyed and illustrated, and their phylogeny is discussed.

In an oil palm plantation in northeast Sumatra, Indonesia, we tested the hypotheses that selection of pupation site by female bagworms, Metisa plana (Walker), influences the distribution of emergent larvae, and that intertree dispersal by larvae is density dependant. Similar intratree distributions of empty female pupal cases and early instars and significant regressions between numbers of female pupal cases and larvae per leaf for 36 out of 39 palms indicated that larvae generally remain on the same leaf where they emerged. Proportions of early instars per female pupal case decreased with increasing densities of female pupal cases per tree and were greater on trees surrounding most heavily infested palms, suggesting that intertree dispersal of early instars is density dependent. Interspecific comparisons of life history constraints between M. plana and the allopatric bagworm Oiketicus kirbyi (Guilding) reveal different selective pressures that may have converged and favoured the development of an identical life history trait.

Zarhopalus debarri Sun sp.nov. reared from the loblolly pine mealybug, Oracella acuta (Lobdell), in the southeastern United States is described.

Three cereal aphids, Rhopalosiphum padi (L.), Schizaphis graminum (Rondani), and Sitobion avenae (F.), invade wheat fields in the northern Great Plains each spring, and populations occasionally reach economic levels. The first objective of this study was to describe the spatial distribution of three species of cereal aphids infesting hard red spring wheat (Triticum aestivum L.). The second objective was to develop two sampling plans for cereal aphids using individual stems as the sampling unit, a sampling plan with fixed levels of precision and a sequential sampling decision plan based on total numbers of aphids present. Aphid population estimates were collected from 47 eastern North Dakota spring wheat fields during 1993–1995. The number of aphids per stem were counted on 100–350 stems per field. Taylor’s power law and Iwao’s patchiness regression were used to analyze the spatial distribution of the aphids. Rhopalosiphum padi and S. avenae exhibited an aggregated distribution, whereas S. graminum was distributed randomly in the field. Taylor’s power law provided a better fit to the data than Iwao’s patchiness regression. Sample size requirements for precision levels of 0.10, 0.15, and 0.25 were estimated with Taylor’s regression coefficients. Required sample sizes increased with decreased aphid populations and increased levels of precision. The two sampling plans presented should be useful for research on cereal aphid population dynamics and pest management decision making in spring wheat.

The number and volume of feeding and oviposition holes made by female white pine weevils, Pissodes strobi (Peck), on lateral branches of resistant and susceptible Sitka spruce, Picea sitchensis (Bong.) Carr., were determined. When all possible effects of weevil reproduction on feeding rates were eliminated, by using reproductively noncompetent weevils, there was no significant difference in the number of feeding holes made on the two host types. In addition, the volume of feeding holes was unaffected by host type on day 1. In contrast, when differential reproductive activity was induced by treating weevils with juvenile hormone, and the host factor was eliminated, by using only the susceptible host, higher reproductive activity was accompanied by a significantly larger number of feeding holes. Hormone treatment also led to an increase in the volume of feeding holes in the absence of any influence of host factors. Results are interpreted in relation to the direct effects of host resistance on feeding rates (which determine host acceptability) and the indirect effects of host resistance on feeding rates mediated through the physiology of the weevils (which determine host suitability). Our results show that both the number of feeding holes and their volume are determined primarily through weevil metabolism.

The effects of various diets composed of millet leaves and stems, millet anthers, and animal prey on the development of Forficula senegalensis Serville were studied in the laboratory using mortality, duration of development, and weight at eclosion and at imaginal moult as comparative parameters. A diet of millet leaves and stems did not allow larvae to reach the adult stage. A diet of millet anthers allowed the production of adults, but with high mortality. When fed animal prey, the larvae developed adequately into adults, but with the mixed diet (prey and millet anthers) development was more rapid and the weight of the adults produced was greater. Millet leaves are probably not an important part of larval earwigs diet in their natural environment. They do, however, eat millet anthers and they may also feed on the insect fauna that lives on millet.

Aphelinus daqingensis sp.nov. from northeastern China is described. This species was reared from Aphis sp. feeding on Phragmites communis L. in Heilongjiang Province.

Eggs, larvae, and adults of diamondback moth, Plutella xylostella (L.), and imported cabbageworm, Artogeia rapae (L.), were monitored on cabbage, broccoli, and brussels sprouts [Brassica oleracea (L.) var. capitata, italica, and gemmifera] for 2 years in southwestern Quebec. The first eggs and adults of P. xylostella were observed during the first week of June, and the use of pheromone traps combined with plant sampling permitted detection of three to four generations on each cultivar type. However, adult counts in pheromone traps were not correlated with the number of eggs and larvae on plants. The date at which each generation appeared and their duration varied little between the three Brassica cultivars. An average of 352.7 degree-days (DD) above 7.3 °C were required to complete one generation, but the considerable overlap between generations reduced the usefulness of DD accumulations to predict P. xylostella occurrence. Visual counts of adult A. rapae and plant sampling of eggs and larvae permitted detection of three generations of this species on each cultivar type. The first A. rapae eggs were found during the last week of May, at least 2 weeks before adults were observed. However, butterfly counts were generally correlated with the number of larvae on plants. The dates at which each generation of A. rapae started were similar between cultivar types, and an average of 319.7 DD above 10.0 °C was required to complete one generation.

Attempts at using Perillus bioculatus (F.) for control of Colorado potato beetle, Leptinotarsa decemlineata (Say), have been hampered by an incomplete understanding of the predator’s over-wintering biology. This study determined the effects of photoperiod and life stage of prey (Colorado potato beetle) on tendency for adult females to enter reproductive diapause, duration of the preoviposition period, and mortality of females. Perillus bioculatus showed an increasing tendency to enter diapause rather than to initiate reproductive activities as day length decreased. Females that were fed large beetle larvae (mid to late fourth instar) showed a significant increase in the number of individuals entering diapause compared with females that were fed a mix of beetle eggs and small larvae (first to third instar). Probit analysis was used to estimate the photoperiod that caused 50% of females to enter diapause; these estimates were 15L:9D for females feeding on large larvae, and 14.5L:9.5D for females feeding on eggs and small larvae. Females that were fed large larvae also showed a longer preoviposition period and had a slightly significant higher rate of mortality than those fed eggs and small larvae.

The life history of the white pine cone borer, Eucosma tocullionana Heinrich, was studied from 1992 to 1994 in an eastern white pine seed orchard in Ontario. Adults flew from late May to early July, and egg laying commenced in mid-June. Oviposition coincided with the onset of white pine pollen release. Eggs were laid singly or in clusters on cones, with most of the eggs laid on the basal third of the cone. Head capsule measurements indicated five instars. Larvae fed in cones from mid-June to the end of August. Mature larvae exited the cones and dropped to the ground to pupate. The insect is univoltine. Parasitism by the Hymenoptera, Trichogramma and Apanteles, accounted for 5% of the eggs and 1% of the larvae, respectively. About 40% of the larvae died from being entrapped in resin. There were no significant differences in attack rates by E. tocullionana within the tree except in the middle level, where the south quadrant had significantly higher rates than the north quadrant.

Relatively little information concerning the cuticular hydrocarbon composition of aquatic insects is known. The cuticular hydrocarbons of the aquatic beetle Agabus anthracinus Mannerheim have been identified with the aid of a gas chromatograph coupled to a mass spectrometer. The cuticular hydrocarbon profile comprises n-alkanes (46.8%), n-alkenes (27.1%), and methylalkanes (25.9%) and is basically similar to that of terrestrial Coleoptera. However, the hydrocarbons of A. anthracinus differ in that (i) the shorter chain n-alkanes are present in higher proportion, (ii) there is a relatively lower abundance of methylalkanes, and (iii) the proportion of n-alkenes is significantly higher.

Chlorita nearctica is described from the Yukon Territory and is the first member of its genus found in the New World. A synopsis is presented to the Old World species of Chlorita Fieber, 1866 (Typhlocybinae, tribe Empoascini). A new typhlocybine tribe Forcipatini is created for Forcipata DeLong & Caldwell, 1936 and Notus Fieber, 1866. A synopsis of the genus Notus is presented, with Curta as a subgenus containing only the type species. Notus isolatus sp.nov. is described from Drummond Island, Michigan, in Lake Huron and from Quebec. A synopsis of the genus Forcipata DeLong & Caldwell is presented; all species belong to a single subgenus. Five new species are described: F. forficula from Florida, F. ips from Alaska and Yukon, F. montana from the mountains of British Columbia and Montana, and F. unica and F. xlix from Wisconsin. The New World species of the forcipatine genera are keyed.

The susceptibility of Colorado potato beetle [Leptinotarsa decemlineata (Say), Coleoptera: Chrysomelidae] to entomopathogenic nematodes (Steinernema carpocapsae, ’All’ strain, Nematoda: Heterorhabditae) was tested in the laboratory and the field in 1992 and 1993. Under laboratory conditions, applications of 5.0 × 105S. carpocapsae per square metre to larvae, pupae, and (or) adults resulted in 100% mortality in all experimental groups. Steinernema carpocapsae persisted through the larval–pupal and pupal–adult transitions. A single application of nematodes was sufficient to control the Colorado potato beetle. The following treatments were tested at field sites in New Brunswick and Prince Edward Island: (i) untreated check, (ii) application of nematodes, or (iii) application of insecticides. Straw mulch was either present or absent in each treatment. In 1992 in New Brunswick, nematodes and fenvalerate reduced Colorado potato beetle populations by 31% compared with the untreated check. However, in 1993, differences among treatments were not significant. The results from the field trials in Prince Edward Island were variable; the life expectancy of nematodes is likely shorter in the field than under laboratory conditions. Further investigation into the benefits of repeated applications of nematodes, higher rates, or improvements in application technology are required to achieve consistent control of the Colorado potato beetle.

The genus Bdelyrus Harold is revised. Twenty new species are described: B. amazonensis, B. apaporisae, B. boliviensis, B. braziliensis, B. bromeliatilis, B. genieri, B. gilli, B. grandis, B. howdeni, B. iauaretensis, B. laplanadae, B. leptomerus, B. lobatus, B. metaensis, B. paraensis, B. parvoculus, B. parvus, B. pecki, B. peruviensis, and B. triangulus. Separate keys are given for males and females. Descriptions, illustrations, and range maps are provided, and a phylogenetic analysis is included.

Residual and contact toxicities of several insecticides to larvae and adults of insecticide-susceptible (four insecticides) and insecticide-resistant (three insecticides) Colorado potato beetle, Leptinotarsa decemlineata (Say), were measured in laboratory studies. For both methods of exposure, azinphosmethyl was the least toxic to all life stages tested. The residual toxicity of deltamethrin was at least 4.4-fold higher than either cypermethrin or endosulfan. With the insecticide-susceptible strain, residual toxicities of azinphosmethyl, endosulfan, and deltamethrin were, respectively, 3.5, 5.9, and 4.1 times higher to first instars than to adults and 1.2, 8.1, and 1.6 times higher to third instars than to adults. Contact toxicities of azinphosmethyl, endosulfan, and deltamethrin were, respectively, 3.3, 2.9, and 1.4 times higher to insecticide-susceptible third instars than to adults. In most comparisons, susceptibilities of fourth and third instars were similar. With the insecticide-resistant strain, azinphosmethyl, endosulfan, and deltamethrin were, respectively, 3.2, 1.6, and 8.0 times more toxic to third instars than to adults. The importance of differential life stage toxicity to current control recommendations for Colorado potato beetle is discussed.

An analysis of the primary setae and pores (campaniform sensilla) of first instars of 32 species of Colymbetinae, 61 species belonging to other dytiscid subfamilies, and seven species belonging to other families of Hydradephaga was performed to deduce the ancestral system of primary setae and pores of the head capsule and head appendages of Colymbetinae. Sixty-one setae and 46 pores have been assigned to the ground-plan pattern of the colymbetine larva, 27 setae and 20 pores on the head capsule and 34 setae and 26 pores on the cephalic appendages. The pattern proposed for the Colymbetinae is remarkably consistent and similar to the condition observed within the Carabidae. However, members of the Colymbetinae differ strongly from those of Hydroporinae which are characterized by several secondary losses. A preliminary phylogenetic reconstruction of the relationships of colymbetine genera studied based on 41 larval features suggests that the Nearctic fauna includes two monophyletic lineages: (1) (Agabus Leach + Ilybius Erichson) + Agabinus Crotch, and (2) {[Colymbetes Clairville + (Rhantus Dejean + Neoscutopterus Balfour-Browne)] + Matus Aubé}.