The genus Placosaris Meyrick, type-species P. leucula Meyrick, Sangir, is redescribed. Xanthelectria Meyrick, type-species X. beatrix Meyrick of Java, is sunk as a subjective synonym of Placosaris. The following additional named species are referred to the genus as new combinations: Pyrausta cricophora West, Philippine Is.; Pyr. homoeides West, Philippine Is.; Pyr. triticalis Kenrick, New Guinea; Botys egerialis Snellen, Java, with Xanthelectria beatrix Meyrick as a new subjective synonym; Botys turiusalis Walker, Sarawak, with subjective synonyms B. eriggusalis Walker, Sarawak, B. broesialis Walker, Sarawak, and B. miniatalis Swinhoe, Sumatra; Opsibotys coorumba Hampson, Pyrausta auranticilialis Caradja, Canton; Pyr. subfuscalis Car.; Pachyzancla callistalis Hampson, Assam; Ebulea ochripunctalis Warren, Khasia Hills; Pachyzancla ustulalis Hampson, Ceylon; Ebulea intensalis Swinhoe, Khasia Hills; Psara tiawannalis Shibuya, Taiwan; Ps. intensalis rubellalis Caradja, Lienping, China; this last is considered specifically distinct from Placosaris intensalis. The following new species of Placosaris are described: P. steelei, Burma; P. swanni, Burma; P. lindgreni, Nagrispur; P. dohertyi, Assam; P. arjunoalis, Java and Bali; P. udealis, Assam; P. bornealis, Sarawak and Borneo; P. perakalis, Perak; P. apoialis, Mindanao; P. galogalis, Mindanao. Although the new species are mostly extralimital to Temperate East Asia, they are mostly related to Chinese species.

Eight species of the genus Piagetiella are discussed and illustrated. There are two new synonymies: P. africana (Bedford) (= Tetrophthalmus australis Bedford) and P. titan (Piaget) (= Tetrophthalmus subtitan Bedford). A key is given to the species.

The stabilimentum of orb web spiders is a structure for which several functions, both mechanical and defensive, have been suggested. Argiope argentata (Fabricius) builds a stabilimentum in the form of a white diagonal cross. Analysis of over 2500 webs of this species shows that the perfect cross is seldom built and nearly two thirds of the webs contain no stabilimentum at all. Experiments with wild birds as predators show that they can use stabilimentum-like models in prey location. From these data, and a review of the defensive adaptations of orb web spiders, it is argued that the A. argentata stabilimentum is not an anti-predator device. The evidence for a mechanical function is reviewed and discussed. It is suggested that the stabilimentum provides the spider with a means of making a final adjustment to the mechanical state of the web when this is necessary.

The Helophorus species recorded by McCorkle as H. brevipalpis Bedel, and by earlier workers as H. granularis (L.) is found, on examination of the types, to be H. orientalis Motschulsky, a species widespread in eastern Siberia.The types of H. orientalis are described, and a lectotype is designated. The type of H. sahlbergi Kuwert, a species synonymous with H. orienta’is, is also described. Further Siberian and North American material is described with reference to the type, and the means of distinguishing H. orientalis from H. granularis and H. brevipalpis are discussed.Fossil prothoraces from Pleistocene deposits at Brandon, Warwickshire and Great Billing, Northamptonshire, England, are referred to H. orientalis.The life histories of the three species are compared, and differences in the egg cocoons and larvae are illustrated. H. orientalis is shown by laboratory breeding to be parthenogenetic. In the other species no maleless populations are known, and although there is no proof that they cannot breed without males, this is considered very unlikely.The ecologies of the three species are discussed.

Eighty Engelmann spruce logs (Picea engelmannii Parry), which were distributed in open (bulldozed to clearcut), semi-open (selectively cut), and dense (uncut) spruce forest, were infested with Dendroctonus obesus (Mann.) and Ips pilifrons Sw. and fed upon by northern three-toed and hairy woodpeckers. Sections of the infested boles were covered with screen to prevent woodpecker feeding and all logs were left in the field over one winter and through the following summer. By spring, the spruce beetle brood was reduced approximately 50% in all three forest areas. By fall, the spruce beetle brood suffered a 71, 83 and 52% reduction in the open, semi-open and dense forest, respectively. Spruce beetles appeared to be in greatest numbers in the semi-open forest, resulting in the greatest woodpecker predation there. Woodpeckers did not feed in the open meadows. Estimates in the spring, before the Ips emerged from the logs, showed that woodpeckers reduced the Ips brood by 76 and 11% in the open and semi-open forest, respectively. Ips were not found in dense forest or in meadows.

Acrobasis comptoniella Hulst is univoltine in Michigan. Adults emerge in early July and the females deposit small egg clusters usually on the underside of the leaves of sweet-fern (Comptonia peregrina (L.) Coult.). Larval eclosion occurs about 2 weeks later; there are five instars. The young larvae construct small silken cases and feed on the epidermis and mesophyll of the leaf until late October. Then the larvae, mostly second instars, move to the stems and construct hibernacula in which they overwinter. They vacate the hibernacula in late April, construct frass-covered silken cases, and feed on the leaves until mid-June. Pupation occurs inside the silken case in mid-June. At least 19 species of parasites have been reared from A. comptoniella.

The sugar pine tortrix heavily defoliated the current season’s needles on lodgepole pine during 1965–66 in southeastern Idaho, and during 1967–68 in western Montana. A brief description of the life stages, damage, and observations on the life history and habits are presented. Choristoneura lambertiana (Busck) is a univoltine insect; oviposition and eclosion occur in late July and early August; first instar larvae spin hibernacula and overwinter in bark cracks, under bark scales, and in other protected locations on the tree and emerge in late May and June. Larvae complete development in approximately 6 weeks, and pupate in July. Adults emerge from about mid-July through early August. Mating and oviposition occur within a few days after adult emergence. Five larval stadia are proposed. Sixteen species of parasites were reared from eggs, larvae, and pupae. One predator was observed feeding on larvae in the field.

An illustrated account of the thoracic mechanism of the milkweed bug, Oncopeltus fasciatus (Dallas), is given. The thoracic skeleton including legs and wings is described and this is followed by a discussion of the interaction of these parts with the musculature. The action of the extrinsic and intrinsic leg muscles, being well known, is tabled as are also the origins and insertions of all the thoracic muscles.

Observations on the feeding and mating behaviour of Rhamphomyia spp. in the high arctic are reported. In R. nigrita Zetterstedt the males catch their prey especially in the male swarms of mosquitoes, etc., and carry it to their specific swarming (mating) site, a station controlled by a typical visual marker. In the swarm the male responds to insects hovering above, by rising to within a few inches and then holding a steady distance for some moments. The upper insect, if a male, moves away; if a female, pairing soon takes place, the prey is transferred, and the female feeds on it during mating. Apparently the female obtains insect food in no other way. The prey is rather small, and insufficient for the completion of one ovarian cycle; and the swarming flight, with mating and prey transfer, occurs repeatedly.In R. ursinella Melander hunting and mating are accomplished on the ground. The prey is very small and mating is frequent. The species is virtually non-flying, and the specialized form of the male eye, on which mating in flight depends, is considerably reduced. Similar adaptations occur in other arctic Diptera. R. nigrita, in contrast, maintains fully the normal dependence on sustained flight.The general structure of mating behaviour in the specialized Empidinae (Rhamphomyia, Empis, Hilara) is discussed. As in many Empididae, and other Diptera, mating takes place at an assembly station controlled by a visually recognized swarm marker, and the response to the female is mediated by the large ommatidia of the upper part of the male eye. The "holding flight" however signifies an interposed courtship, or display of prey by the male to the female. In most species only the male captures prey (perhaps without feeding on it himself); the female does not hunt and obtains insect food only by transfer at mating. Courtship with transfer becomes a firmly established behavioural element, and persists even in species which use objects of no value as food (ritualization of prey).The original significance of the prey, on which its role as sign stimulus in mating is based, is its significance as food required by the female for ovarian maturation. When the prey is small in relation to the requirements of the female, the mating process, including the courtship and prey transfer, is repeated (ritualized) so as to provide the female with sufficient food. It is suggested that this ritualization would develop easily once insect prey had become established as the sign stimulus for mating; and could lead on to the sex differences in habits of hunting and feeding.

Notes and records are given for the species in the nine subfamilies of Scarabaeidae occurring on Jamaica. New records for Jamaica include Ataenius scabrelloides Pet. and Ataenius havanensis Balth. in the Aphodiinae, and Hybosorus illigeri Reiche in the Hybosorinae. The following new taxa are described: Cioeotus farri n. sp. and Cloeotus pecki n. sp. in the Acanthocerinae; Anomala sandersoni n. sp. in the Rutelinae; Stenocrates beckeri n. sp., Calypsoryctes dynastoides n. g., n. sp., and Epiphileurus jamaicensis n. sp. in the Dynastinae. Reasons are given for considering the deletion of at least four names from the lists of Jamaican Scarabaeidae.

Differences in the behavior of scale insects induced by their host plants has been observed, principally, in uniparental, bisexual, univoltine species. Behavior in endoparasites of such species also may be thus modified. The phenomena involved, reproductivity, sexuality, voltinism and, with the parasites, host-regulation, are related to the environmentally induced immunity of the host plant to its indigenous scale insects.This immunity, when not a regional phenomenon, is necessarily sporadic. When operative, it may he as complete as generic-immunity. Periodic host plant non-susceptibility is considered to he a physiological response to meteorological and edaphic conditions, a response usually rendering the plant temporarily unsuitable for coccid development. The interpolation of immune periods in the life of a coccid’s normal host plant necessarily disrupts the continuity of the host-regulative action of the coccid’s parasites. Host plant pheno-immunity was first clearly manifested in regions where Lecanium corni Bouché, L. tiliae (Linnaeus), and Saissetia oleae (Bernard) free of their regulative parasites, reproduced in great abundance. In regions to which these coccids are indigenous the limitation of their outbreaks to artificial monocultures attested to the obscure nature of host plant pheno-immunity. The cessation of host plant immunity to coccids, the subsequent heavy reinfestation, and then the parasitic elimination of the outbreak attested to the host-regulative power of parasitization.

The valval shapes of 314 male Nearctic Limenitis (including 15 samples from nine localities and 20 laboratory-bred hybrids) were examined for anatomical differences. Seven phenotypically different forms are included as follows: L. arthemis, astyanax, the intergrade form proserpina, L. archippus, the rare hybrid form arthechippus, L. lorquini, and L. weidemeyerii. The claspers of each specimen were dissected, mounted on slides, and photographed. Counts and measurements were made of eight larval characters (including four apical features: the number of distal teeth, distal width, and dorsal and ventral angles, as well as four basal traits: valval length and base, and the length and basal width of the inner process), and right forewing length. The data were compared between and among samples by canonical analysis and by one-way analysis of variance tests. Forms of the arthemis–astyanax complex possess no obvious morphological differences in their valvae. The apical characters are constant throughout the group, although the basal valval traits and forewing length show variation in size which is inversely correlated with latitude. The similarity of valval structure in these forms is evidence that they are conspecific. Consistent differences in the apical shapes and valval characters of arthemis, archippus, lorquini, and weidemeyerii confirm that they represent valid species. The valvae of the hybrid form arthechippus are intermediate between the two parental types. The relationships of valval structure to hybridization and genetic isolation are discussed, and consideration is given to the probable evolutionary affinities of the common forms, and how they may have arisen.

Astichus notus n. sp. reared from the birch bracket fungus Polyporus betulinus (Bulliard) Fries and woody fungus Ganoderma applanatum (Wallr.) Pat. in eastern Canada is described and illustrated and a key is included to the species of America, north of Mexico.

The flea beetle Altica carduorum Guer. was released in four provinces in Canada to aid in the control of Cirsium arvense (L.) Scop, but did not survive in open fields with the exception of a small colony at Lacombe, Alta. It thrived, however, at four locations in different climates when protected by field cages. The mortality of the eggs and(or) the larvae reached 91%, that of the overwintering adults 83%. The mortality of the immature stages was apparently mainly due to predation and at a release site near Belleville Leptus sp. near curtipes Schweizer and Sphaerolophus sp. (Erythraeidae: Acarina) were implicated in tests with A. carduorum eggs labelled with P32. Field and laboratory experiments showed that dry continental summers, such as occur at Summerland, B.C., and Lacombe, Alta., were probably not detrimental to either egg development or pupation.

The morphology and histology of the internal reproductive system of the male spruce budworm moth, Choristoneura fumiferana (Clemens), is described and discussed.

Aphalara steironemicola is described and illustrated. Its only known host is Steironema ciliatum Linnaeus (Primulaceae).

The heat requirements for diapause termination in pupae of Hyphantria cunea are subject to a high degree of generic control. Offspring–parent regression analysis based on a positively assortative mating pattern, which is the normal pattern in field populations of this species, provides a slope of 0.60. Positive skewness in the distribution of heat requirements can be reduced by conversion to logarithms. The inheritance of heat requirements is sex-linked, with the female being the heterogametic sex. Fitness characters that are significantly correlated with heat requirements affect larval and pupal survival rates and the weight of both male and female pupae. When the effects of these correlated survival rates are removed mathematically, the slope of the offspring–parent regression is increased to 0.80.Changes in the heat requirements of natural populations, in relation to the amount of heat available each year, influence their survival rates. The comparison of actual and calculated changes, based on models for heritability and selection pressures, will be the subject of a later paper in this series on H. cunea.

This review of the genus Psychoglypha Ross includes a discussion of the eight species currently assigned to the genus and the description of seven new species. The new species are from Oregon, California, Nevada, and Idaho. Except for one species, all members of the genus are northern and western in distribution. The majority of species are cold-adapted and may be found late in the season.

The anatomy and functions of the male and female reproductive organs of Allothrombium lerouxi Moss are described in detail. In the male, the reproductive organs consist of paired testes, paired vasa diferentia, a median seminal vesicle, a median ejaculatory duct, bursa expulsatoria, a penis, and a median accessory gland; in the female, they consist of paired ovaries, paired oviducts, a median uterus and a vagina. The function of the parts in the male differs from that reported in other species of Trombidiformes, and in females fertilization takes place in the spongy epithelium of the uterus instead of in the oviducts as in oribatids. Females also lack a receptaculum seminis and accessory glands.

An olfactometer is described for determining the responses of individual pedestrian beetles to attractants. The main features are a covered runway, a general air flow containing a well-defined narrow odor stream, and an on–off control of odor flow.