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The antennae of the sawyer beetles Monochamus notatus and M. scutellatus were examined with the light and scanning electron microscopes to determine the types, number, distribution and innervation of the sense organs. Nine types of sensilla are described. Both short, thin-walled pegs (sensilla basiconica) and reversely curved thick-walled hairs (sensilla trichodea) are chemoreceptors. There are three types of long, thick-walled hairs (sensilla chaetica) which may be mechanoreceptors. One of these is modified in males to form unique snail-shaped pegs. A few domeshaped organs, probably campaniform sensilla, were found.In addition to sense organs, many glands occur in association with the sensilla, and the antennae are well supplied with dermal glands connected by canals to small pores on the surface.Throughout eastern Canada, wood borers of the genus Monochamus present the greatest single threat to softwood logs that must remain in the woods through the summer, and to standing trees killed by fires. Monochamus larvae are capable of boring into wood to a depth of nine inches or more (Gardiner, '57), and Raske and Safranyik ('70) estimate that as few as two or three of the resultant holes per square foot result in a 30 % downgrade in the value of lumber. The two economically important representatives of this genus found in New Brunswick are M . notatus (Drury), which breeds mainly in white pine (Pinus StTobus), and M . scutellatus (Say), which is less specific in its choice of host and can be found on several species of the Family Pinaceae. This work is part of a study of the sensory physiology of host attraction in these beetles.Several recent reviews deal with the structure and function of the receptors found on insect antennae (Slifer, '70; Schneider, '64; Lewis, '70) and a small body of literature with the receptors of various beetles. To date there is no work on receptors in cerambycids. MATERIALS AND METHODSSpecimens of both sexes of Monochamus J. MORPH., 146: 513-532. notatus and M . scutellatus were either collected in the field or raised in the laboratory in white pine logs (Pinus strobus). A small number of larvae were raised on an artificial diet (McMorran, '65) in order to obtain newly emerged animals with soft cuticle. Histological techniquesTwo approaches were made to obtaining serial sections of the heavily sclerotized cuticle. The most successful method consisted of softening the fixed antennae for four days in 30% hydrogen peroxide followed by double embedding in 2 % celloidin and Tissuemat using the method of Peterfi (Gray, '54). For harder blocks or thin sections, fixed antennae were embedded in plastics such as methacrylate (Pease, '60) and for serial sections some of the plastic blocks were trimmed closely and reembedded in Tissuemat. Stains used included Harris' hematoxylin and eosin, Mallory's triple stain (Gray, '64), osmium tetroxide and ethyl gallate (Wigglesworth, '57), and for methacrylate sections, 1 % toluidine blue (Pease, '60).To reveal permeable areas of the cuticle the crysta...

The calling behaviour of 0‐day‐old and 2‐day‐old virgin female eastern spruce budworm moths, Choristoneura fumiferana (Clem.) was observed during exposure to different concentrations of the synthetic female sex pheromone. Regardless of whether the females were exposed to pheromone or not, there were two daily peak periods of calling activity, one in the afternoon and the other after dusk. Those moths exposed to pheromone commenced calling at least 2 h earlier during their first peak of calling activity. Also, a greater number of moths engaged in calling when exposed to pheromone than those under control conditions. RÉSUMÉ Modification du comportement d'appel des femelles de Choristoneura fumiferana exposées à la phëromone sexuelle synthétique de leur propre espèce. Des expériences ont été menées au laboratoire pour examiner si la phéromone sexuelle synthétique de C. fumiferana pouvait altérer le comportement d'appel de femelles vierges de la même espèce. Un appareil a été conçu pour libérer alternativement ‐ à des intervalles déterminés ‐ un courant d'air portant de la phéromone sexuelle ou un courant d'air pur, dans plusieurs flacons contenant des femelles vierges. Le comportement sexuel de mouches de 0 et 2 jours a ainsi été observé. Indépendamment de l'exposition des femelles à la phéromone, il y avait deux pics quotidiens d'activité d'appel, l'un dans l'après‐midi et l'autre après le crépuscule. Des papillons exposés au 1 × 10−6 mg ou 1 × 10−3 mg de phéromone avaient un premier pic d'appel au moins antérieur de 2 heures par rapport aux témoins. Ainsi il y avait un plus grand nombre de papillons engagés dans une activité d'appel en présence de la phéromone que chez les témoins.

The innervation of a pregenital, the genital, and postgenital segments of the male and female of Schistocerca gregaria (Forskäl) is described in detail and is compared with other orders of the Insecta.

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