In the 1960s, the prediction that synthetic juvenile hormones (JHs) and their analogs would form the basis of a new generation of insecticides with enhanced target specificity greatly stimulated research on this hormone. Although JH-based insecticides were found to be effective against certain groups of insect pests, their shortcomings soon became apparent; however, current JH research provides new opportunities and ideas for the development of innovative integrated pest management (IPM) tools and strategies aimed at disrupting JH functions. Interfering with JH endocrinology requires that we either artificially increase JH titers at stages of development when titers are normally low or artificially reduce JH titers at stages of development when titers are normally high. Our discussion is organized around these two conceptual approaches and covers such areas as (i) the isolation and cloning of JH receptors; (ii) the characterization of polydnavirus and entomopoxvirus gene products responsible for the inhibition of host metamorphosis; (iii) the isolation and molecular cloning of allatostatins and the design of allatostatic pseudopeptides; (iv) the characterization of JH biosynthetic enzymes specific to the Lepidoptera; (v) the characterization of regulatory material originating from parasitic wasps of the genus Chelonus Panzer (Hymenoptera: Braconidae), which induce precocious metamorphosis in their hosts; (vi) a tree resistance mechanism involving anti-JH effects resulting in the failure of female insects to produce and lay eggs; and (vii) the cloning of JH esterase and epoxide hydrolase cDNAs and the production of recombinant baculoviruses that overexpress these JH-degradative enzymes.

The Aphodiine fauna of the Galápagos Islands, Ecuador, is reviewed. Ten species in two genera are now recorded for the archipelago. Two species, Ataenius cristobalensissp.nov. and Ataenius floreanaesp.nov., are described. Ataenius leleupi Petrovitz is placed in synonymy. Two previously described species, Ataenius gracilis (Melsheimer) and Ataenius liogaster Bates, are newly recorded as recent introductions to the islands. A key to species is included. We hypothesize that wing dimorphism for the species of the genus Ataenius Harold endemic to the Galápagos underwent the following evolutionary stages: (1) colonization, (2) adaptation to high-elevation moist forest, and (3) speciation and extinction.

A new species of Thoronidea Masner and Huggert, Thoronidea cerradensissp.nov., is described from the central Brazilian state of Goiás. This species is closely associated with stream habitats in cerrado (savanna) vegetation and probably parasitizes the eggs of aquatic Hemiptera. The male of the genus is described for the first time. The male antenna of T. cerradensis is 11-merous and A4 is exaggerated. The original generic diagnosis is modified to accommodate this new species.

Data from 18 studies carried out on dung beetles from temperate North America (north of 25 ° latitude) are compared to verify the existence of some geographical pattern in the variation of three parameters: (1) species number, (2) taxonomic composition, and (3) number of introduced species. Southern localities are characterized by a larger number of species and a significantly higher number of scarabaeine species than northern localities (only southern communities located inside the Chihuahuan desert do not conform to this pattern). To explain the latitudinal pattern in faunistic composition and number of species, historical factors are postulated. Foreign species of the tribe Aphodiini seem to be more frequent in the northern localities where more aphodiine native species occur. In contrast, foreign species of the subfamily Scarabaeinae are not more frequent in the southern localities with a greater number of native scarabaeine species. These results are consistent with the hypothesis that the more diverse assemblages of native dung beetle are more resistant to invasion by foreign species.

Third-instar larvae of Phyllophaga (s.str.) ilhuicaminai Morón and Phyllophaga (Listrochelus) cuicateca Morón and Aragón are described. Larvae of P. ilhuicaminai were taken only from the roots of Limonium sinuatum (L.) Miller (Plumbaginaceae), an ornamental herb growing in fields near Atlixco, Puebla, Mexico. Larvae of P. cuicateca were found only on roots of Amaranthus hypocondriacus L. (Amaranthaceae) in fields near Altepexi, Puebla, Mexico. These larvae cause damage to the root system of both plant species under culture. Illustrations of diagnostic structures, a brief discussion on the differences between these larvae and other Phyllophaga Harris larvae, and a key to the Mexican larvae of the genus are included.

Random deviations from perfect symmetry in bilateral traits, fluctuating asymmetry, are thought to reflect developmental stability: the ability of an individual to buffer against genetic and (or) environmental stress during development (Palmer and Strobeck 1986). Fluctuating asymmetry is often regarded as an indicator of individual quality or fitness (Møller and Swaddle 1997); however, factors underlying fluctuating asymmetry are not well understood (Markow 1995). It has been suggested that heterozygosity, ploidy, and genomic coadaptation (hybridization) are genetic factors affecting the magnitude of fluctuating asymmetry (Palmer and Strobeck 1986; Markow 1995; Møller and Swaddle 1997). Insects having a haplodiploid sex-determining mechanism present opportunities to examine the relationship between ploidy and fluctuating asymmetry. In hymenopterans, females are diploid and males haploid. Thus the effects of ploidy can be investigated by contrasting males and females within a population (e.g., Clarke 1997). Diploid females, in which deleterious recessives reducing developmental stability could be masked, may be expected to have smaller asymmetry than haploid males (e.g., Brückner 1976; Smith et al. 1997). In this paper, we compare the level of fluctuating asymmetry in forewing venation of males to that of females in the carpenter bee Xylocopa appendiculata circumvolans Smith.

Susceptibility of many insects to baculoviruses decreases with host development (Hochberg 1991), whereas the time required for infected hosts to die increases with larval age (Boucias et al. 1980; Bucher and Turnock 1983; Smits and Vlak 1988). The actual mechanism of this phenomenon, however, has not been established in many cases. The present study was undertaken to investigate the effect of larval age on the susceptibility of Spodoptera litura Fabricius to nuclear polyhedrosis virus (NPV) through oral and intrahaemocoelic routes of infection.

A process-oriented model was recently developed to simulate the efficacy of spray products containing Bacillus thuringiensis Berliner subsp. kurstaki (Bacillaceae) against the spruce budworm, Choristoneura fumiferana Clemens (Cooke and Régnière 1996). The model accurately predicted foliage protection and larval population reduction during validation spray trials (Régnière and Cooke 1998; Cooke and Régnière 1999). The impact of treatment on budworm generation survival was generally well mimicked by the model except for a consistent overestimation of survival at the end of immature development in the treated plots. Régnière and Cooke (1998) speculated that residual mortality due to treatment may be occurring during the pupal stage. Carry-over of B. thuringiensis from larvae to pupae has been documented for spruce budworm (Klein and Lewis 1966) and several other Lepidoptera (Legner and Oatman 1962; Angus 1965). Although we recently investigated the response of spruce budworm larvae to ingestion of sublethal doses of B. thuringiensis (Pedersen et al. 1997), effects on pupal survival or adult emergence were not examined. In this note, we report the results of an experiment designed to assess such effects.

Synthetic sex pheromones released in a loblolly pine, Pinus taeda L. (Pinaceae), seed orchard interfered with the ability of male coneworm moths, Dioryctria Zeller spp. (Lepidoptera: Pyralidae), to locate traps baited with sex pheromones or live females. Pherocon 1C® traps baited with synthetic pheromones or live conspecific females were hung near the center of two 1.2-ha circular plots during emergence of Dioryctria amatella (Hulst), Dioryctria disclusa (Heinrich), and Dioryctria merkeli (Mutuura and Munroe). In a paired design, trap catches for the mating-disruption treatment with synthetic pheromone dispensers consisting of three polyvinyl chloride rods placed in every tree were compared with the control treatment. Treatments were alternated at intervals of 2–3 d. Trap catches of D. amatella were reduced by 91% when plots were treated with 2.5 g/ha of Z-11-hexadencenyl acetate. Catches were reduced by 99.5% for D. disclusa and by 97% for D. merkeli when plots were treated with 12.5 g/ha of Z-9-tetradecenyl acetate, whereas catches of D. amatella were unaffected by this mating-disruption treatment. Daily disappearance of Z-9-tetradecenyl acetate from the dispensers averaged 0.46 g/ha or less. Manually placing dispensers on nylon lines in the tops of trees was an effective method for releasing synthetic Dioryctria pheromones in the orchard. These data suggest it may be feasible to prevent mating of Dioryctria spp. in pine seed orchards by using synthetic pheromones for mating disruption, but large-scale tests will be required to demonstrate cone protection.

We used laboratory experiments to study the effects of rearing density on nymphal duration, dispersal dimorphism, and reproduction of two wing-dimorphic water strider species, Gerris buenoi Kirkaldy (wing morphs macropterous and micropterous) and Gerris pingreensis Drake and Hottes (mainly apterous and macropterous), that specialize, respectively, in temporary and permanent habitats. First-instar nymphs from field-collected or laboratory-cultured parents were reared with superabundant food at high (2900 or 3100 first-instar individuals/m2) or low (145 or 155 first-instar individuals/m2) starting density under a photoperiod of 19L:5D and at 20 ± 2 °C. Average nymphal period of both species under high density was significantly shorter by 4–5 d than under low density. There were no significant differences in percent survival between densities in either species. In G. pingreensis all new adults were apterous and entered reproductive diapause. In contrast, both wing morphs were expressed in G. buenoi; however, a lower proportion of macropters emerged under high density than under low density. All females of G. buenoi tested were reproductively active, regardless of wing morph. There was no effect of density on preoviposition period for G. buenoi of either wing morph, although preoviposition period was about twice as long in long-winged as in short-winged females. In G. buenoi, nymphal crowding promotes development of nonflying reproductives, which allocate nutritional resources to rapid reproduction rather than dispersal, at least when food conditions are sufficient. In G. pingreensis, nymphs that develop faster under crowding may be less subject to cannibalism and intraguild predation.

In 1997, larvae of the cutworm moth, Ochropleura implecta Lafontaine, caused economic damage to cranberries (Vaccinium macrocarpon Aiton; Ericaceae) on several neighbouring farms in Richmond (49° 10′N, 123°07′W), British Columbia, Canada. This is the first report of O. implecta on cranberries. Published host records for O. implecta include willow and a variety of herbaceous plants, such as clover and endive (Crumb 1956; Lafontaine 1998), but there are no reports of pest status on any crop. On the affected cranberry farms, larvae partially consumed unripe and ripe berries in July and August. On one farm, damaged fruit was downgraded from fresh fruit sales to the juice market, resulting in an estimated loss of $40 000 Can.

Plant bugs, Lygus Kelton, damage many crops in western Canada (Kelton 1980; Wise and Lamb 1998; Wise et al. 2000), the common species in Manitoba being Lygus lineolaris (Palisot de Beauvois), Lygus borealis (Kelton), and Lygus elisus Van Duzee (Gerber and Wise 1995). Reports of plant bugs on flax, Linum usitatissimum L., are limited to an oviposition study (Painter 1927) and anecdotal descriptions of feeding damage in Canada (Beirne 1972) and Europe (Ferguson and Fitt 1991). In western Canada, flax is grown as an oilseed crop on about 600 000 ha annually (Canada Grains Council 1999). The objectives of this study were to determine (i) the species of plant bugs in oilseed flax, (ii) their ability to complete development in flax, (iii) the number of generations they complete, and (iv) the yield loss they cause.

Inundative releases of Trichogramma exiguum Pinto and Platner were evaluated for suppression of the Nantucket pine tip moth, Rhyacionia frustrana (Comstock), in first-year loblolly pine, Pinus taeda L., plantations. Three releases, spaced 7 d apart, were made in three 0.4-ha plots during second-generation R. frustrana egg deposition. Each release included three cohorts of T. exiguum developmentally separated by 25 degree-days. Mean ± SD field release rate for each cohort was 328 238 ± 88 379 females/ha. Mean T. exiguum emergence under laboratory conditions for released cohorts was 96 ± 2%, with 74 ± 3% females, of which 1 ± 1% of females displayed brachyptery; female longevity was 18 ± 3 d. Field emergence averaged 96 ± 4%. Parasitism of R. frustrana eggs was significantly increased, ranging from 40 ± 19 to 73 ± 22% in T. exiguum-treated plots and 17 ± 17 to 67 ± 21% in control plots. Data from all treated plots combined showed R. frustrana egg survival (hatching) was significantly reduced by 46%, and larval populations were significantly reduced by 60%. There was no significant difference in the percentage of terminals damaged between T. exiguum-treated (31 ± 16%) and control plots (45 ± 10%); however, length of terminal damage was significantly lower in treated plots. The percentage of damage to top whorl shoots was significantly lower in T. exiguum-treated plots compared with control plots, but there was no significant difference in length of tunneling damage. Damage to remaining shoots was not significantly different between T. exiguum-treated and control plots. Microhabitat significantly influenced both mean maximum and minimum temperature and the number of consecutive hours per day that were at or above 35 °C (critical temperature for T. exiguum survival). Soil surface with no cover had the greatest number of hours at or above 35 °C, followed by soil surface with herbaceous cover, and canopies of small trees (0.4 m tall). Canopy habitats in larger trees (0.9–1.8 m tall) had the most moderate temperature conditions. Parasitoid emergence was significantly reduced in response to increasing number of consecutive hours at or above 35 °C. Predation of parasitoids prior to emergence was significantly affected by microhabitat and by the length of time capsules were in the field before T. exiguum emergence (i.e., cohort number).

Pitfall traps are used extensively to sample ground-dwelling arthropods for systematic and ecological studies. They are inexpensive and easy to use and can be operated for relatively long periods of time without maintenance. These traps can collect arthropods in numbers that are suitable for rigorous statistical analysis, although their efficiency is influenced by many biotic and abiotic variables (Greenslade 1964; Spence and Niemelä 1994). Typically, pitfall traps are most productive when they are buried in the substrate, with the upper edge flush with the soil surface; traps with their upper edge above the substrate are much less effective (Greenslade 1964). Because of this, studies of ground-dwelling arthropods in habitats where soil is thin or lacking, or where digging is difficult, are left with no satisfactory alternatives to pitfall traps. A ramp pitfall trap developed by Bostanian et al. (1983) is useful in these habitats because it can be placed on the ground surface without digging. However, the original metal design was strongly biased toward the collection of large (>10 mm) ground beetles (Coleoptera: Carabidae) (Bostanian et al. 1983); it was also large, bulky, and relatively expensive. In this paper, we describe a ramp pitfall trap that is inexpensive, easily constructed, and durable. The trap is light, portable, easily installed, and effective in collecting all sizes of arthropods and can be used in many habitat types.