North American species of the Oeneis polixenes (Fabricius, 1775) complex are reviewed. Two new subspecies, Oeneis polixenes luteus and Oeneis polixenes woodi, as well as one new species, Oeneis philipi, are described from northwestern North America. Oeneis polixenes peartiae (Edwards, 1897) is synonymized with Oeneis polixenes subhyalina (Curtis, 1835).

The name Neoligiagen.nov. is proposed for the “Oligia” semicana (Walker) species group in North America and 12 species, N. rubirena sp.nov., N. pagosa sp.nov., N. hardwicki sp.nov., N. inermis sp.nov., N. invenusta sp.nov., N. albirena sp.nov., N. lancea sp.nov., N. elephas sp.nov., N. lillooet sp.nov., N. surdirena sp.nov., N. canadensis sp.nov., and N. atlantica sp.nov. are described. Hadenella laevigata Smith is synonymized (synonymy restored) under Hadena tonsa Grote and Hadena hausta Grote is synonymized (synonymy restored) under Miana semicana Walker. Adults of all species are illustrated as well as male and female genitalia, where known.

The North American members of the genus Operophtera Hübner (Lepidoptera: Geometridae) are revised to include three species: O. brumata (L.), O. bruceata (Hulst), and O. danbyi (Hulst). Operophtera occidentalis (Hulst) is now treated as a subspecies of O. bruceata. All species are illustrated and characters to distinguish the species are given. The most useful characters for separating O. brumata from O. bruceata include the following: (1) hindwing dorsal surface with discal dot, which is almost always visible on O. bruceata but absent from O. brumata; (2) forewing colour, which is grey-brown or light brown in O. bruceata but reddish-brown in O. brumata; (3) abdomen colour, which is golden-brown to brown in western O. bruceata but brown in O. brumata; and (4) the costa of the forewing ventral surface, which is usually golden-brown in O. bruceata but brown in O. brumata. The structure of the genitalia of these two species allows hybridization between O. bruceata males and O. brumata females, but not vice versa.Hypothesized species interrelationships between palaearctic and nearctic Operophtera are illustrated in a cladogram. Maps for the distribution of each species are also included.

A new species, Oeneis excubitor, is described. This species has male valvae similar to those of Oeneis melissa and Oeneis jutta but the wing pattern is roughly similar to that of Oeneis chryxus.

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.

The palearctic cutworm, Apamea ophiogramma (Esper), is reported from North America for the first time. Four specimens were collected at a light trap in Langley, British Columbia, in 1989, 19 in 1990, and 38 in 1991. Descriptions of wing markings and genitalic characters that distinguish A. ophiogramma from the nearctic Oligia fractilinea (Grt.) are provided.

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.

In field studies of pheromone-mediated mating disruption of lepidopteran pests, there are several ways to determine if mate location has been disrupted. One indirect method is to count the number of males caught in sticky traps baited with synthetic pheromone. A reduced catch in pheromone-treated plots relative to control plots shows that males were unable to find the source of synthetic pheromone and suggests that mating has been disrupted. More direct methods are: (1) to count the number of males attracted to sticky traps baited with virgin females; or (2) to assess the incidence of mating of (a) feral females collected in light-, bait- or other traps, (b) females caged with males in pheromone-treated areas, or (c) virgin females placed in the field and later retrieved. Females may be tethered with thread to non-sticky traps or partially dealated and placed on a “mating table” from which they cannot escape.

The North American species of Brachylomia Hampson, 1906 are revised and four new species (B. cascadiasp. nov., B. obscurifasciasp. nov., B. pallidasp. nov., and B. sierrasp. nov.) are described. The monotypic genus Lomilysis Franclemont, 1937 is synonymized with Brachylomia. Epunda onychina Guenée, 1852, which is currently placed in Brachylomia, is reclassified as a senior synonym of Egira alternans (Walker, [1857]), but Epunda onychina, not being associated with any known species in more than 150 years, is treated as a nomen oblitum, so Egira alternans is a nomen protectum under provisions of Article 23.9.2 of the International Code of Zoological Nomenclature. Adults and genitalia of Nearctic species of Brachylomia are figured.

The species of the genus Hyppa Duponchel are revised and a new species is described. Adults of all species are illustrated, as are male and female genitalia where known. A neotype is designated for Hadena ancocisconensis Morrison. The concept of Hyppa contrasta is modified from that of a southern Appalachian endemic to that of a common transcontinental species.

Alastriagen. nov. is described, and Callierges tropicalis Schaus is transferred to the genus. Alastria chicosp. nov. is described from western North America and Alastria machosp. nov. is described from Costa Rica. We provide illustrations of the adults and genitalia of all three species, as well as the male genitalia of two related genera, Nedra Clarke and Actinotia Hübner.

The species of the Lithophanelepida Grote complex are reviewed and two new species of the genus Lithophane Hübner from western North America are described. Adults of all species are illustrated, as well as male and female genitalia (where known) and larva of L.lepida and Lithophane itata (Smith). A key to species of the L. lepida group is provided.

Blackheaded fireworm (Rhopobota naevana (Hbn.)) mating can be disrupted by pheromone components released from spiral polyvinyl chloride (PVC) dispensers in large field plots on cranberry (Vaccinium macrocarpon (Aiton) (Ericaceae)) farms. The main pheromone component ((Z)-11-tetradecen-1-ol acetate (Z11-14:Ac)) or a blend similar to natural pheromone (Z11-14:Ac, (Z)-11-tetradecen-1-ol (Z11-14:OH), and (Z)-9-dodecen-1-ol acetate (Z9-12:Ac)) was released from PVC dispensers into 0.8-ha plots on cranberry farms. Regardless of the treatment, free-flying males in treatment plots located fewer than 5% of individually caged virgin females, whereas mate location in most control plots ranged from 14%–75%. Location of pheromone lures loaded with 1.0 mg of the three-component blend was reduced in both treatments, but not to the same extent as was location of females. The magnitude of mating disruption indicated by 0.01-mg lures was similar to that indicated by caged females. Estimated release rates from dispensers loaded with Z11-14:Ac alone were linear and similar in both years of the study, declining from 575–720 mg/ha per day to 175–220 mg/ha per day after 100 days. Three-component dispensers placed in the field in July 1994 showed a steeper decline in release rates of Z11-14:Ac and a change in component ratios from 6.2:2.5:1 to 8:2:1 (Z11-14:Ac: Z11-14:OH: Z9-12:Ac) over the 60-day release period. After one season of mating disruption, the number of eggs and the number of foliar samples with larval feeding shelters were not consistently reduced in treatment plots. Mated females may have dispersed into the plots and oviposited. PVC dispensers effectively disseminate pheromone for mating disruption but are labor-intensive to use. In the cranberry system, their use might be limited to research plots and isolated farms of <8 ha.

The North American species of the genus Cosmia Ochsenheimer are reviewed and four species are recognized: Cosmia calami (Harvey), C. praeacuta (Smith) comb. nov., C. epipaschia (Grote) comb. nov., and C. elisaesp. nov.Achytonix McDunnough syn. nov. is synonymized with Cosmia subgenus Calymnia Hübner. Namangana praeacuta nigramaculata Barnes et Benjamin and Namangana praeacuta orae Barnes et Benjamin are synonymized with Cosmia praeacuta. Illustrations of adults and genitalia are provided.