Pimpla turionellae (L.) (= exarainator F.) is a pupal parasite of many species of Lepidoptera. During propagation of this species for release in Canada against the European pine shoot moth, Rhyacionia buoliana (SCHIFF.), and the spruce budworm, Choristoneura ]umi]erana (CL~.M.), data were obtained oil the influence of the size of the host pupae on sex ratio, development time, and size of the adults. Material and MethodsMated females of P. turio~ellae that had been reared in the laboratory on a number of medium-sized hosts were plaeed singly in cages that measured 4 • 4 • 2 1/2 inches. They were fed daily a 10 per eent solution of honey and sprayed twiee daily with tap water. Pupae of different hosts were introduced into the cage and eaeh was removed as soon as the parasite had laid one egg on it. The hosts were then weighed, placed singly in glass vials, and incubated at 22-24 oC. and 60 q-5 per cent relative humidity. Weight was used as a measure of host size because of differences in shape between moth and butterfly pupae. When the parasites emerged they and the host remains were weighed separately. As this species is arrhenotokous, only data from females that produced both males and females were used. Pupae that did not produce parasites were dissected.Nine speeies of lepidopterous hosts were used. Anagasta k4~hniella (ZELL.) and Galleria mellonella (L.) (Pyralidae) were taken from labo-

The larvae of the European pine shoot moth, Rhyacionia buoliana (Schiff.), feed on several species of hard pines, of which the most economically important are red pine, Pinus resinosa Ait., and Scots pine, Pinus sylvestris L. Approximately one hundred million trees of each species mere planted in southern Ontario since 1905, most of them since 1925. Many pure and mixed stands are now infested by R. buoliana which has no apparent preference for either host tree.

Females of I. conquisitor were conditioned to associate colour with the presence of hosts. Conditioning was important only during searching and did not affect the distribution of attacks once hosts were found. The ability of this species to associate colour with the presence of hosts could increase its efficiency as a parasite. Females of I. conquisitor showed an innate preference for blue over yellow.

The Canadian Entomologist 130: 305 -314 (1998) 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 (whicb determine host aeceptability) 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.

Females of Nemeritis canescens (Grav.) were conditioned to associate the odour of geraniol with the presence of hosts. Females conditioned for 10 days retained the conditioned response for 6 days. Associative learning in N. canescens, an oligophagous parasite, is less strong than in Itoplectis conquisitor (Say), a polyphagous parasite. This finding may reveal a general difference between oligophagous and polyphagous parasites.

Can. Ent. 118: 487-491 (1986) Microplitis mediator (Haliday) is being considered for introduction into Saskatchewan to augment the biological control of the bertha armyworm, Mamestra con$gurata Walker. It was reared in the laboratory on larvae of the bertha armyworm. Notes on the life history and descriptions of the egg and three larval stages are given. ResumeOn envisage l'introduction en Saskatchewan de Microplitis mediator (Haliday) pour renforcer la lutte biologique contre la ltgionnaire bertha, Mamestra conjigurata Walker. Le parasite a Ct C Cleve en laboratoire sur des larves de la 1Cgionnaire. Les auteurs prCsentent des observations sur la biologie et la morphologie des oeufs et des trois stades larvaires.

The European, or Essex skipper, Thymelicus (= Adopaea) lineola (Ochs.), was accidentally introduced into North America at London, Ontario, sometime before 1910 (Saunders, 1916). The history of its subsequent spread through southern Ontario and adjoining parts of Michigan and Ohio was reviewed by Pengelly (1961), who received the first report of extensive damage to hay and pasture crops by this insect in Ontario from the Markdale area of Grey County in 1956. A survey in 1958 (Pengelly, 1961) showed that the skipper “appeared to be present throughout the southern part of the province except for the Bruce peninsula and possibly the Windsor area. The northeasterly boundary appeared to he along a line from Midland, south around the west side of Lake Simcoe, east to Lindsay and south to Whitby.” The present author collected T. lineola larvae from the Belleville area for the first time in 1959.

A chemically defined, synthetic medium that induces oviposition in the parasite Itoplectis conquisitor (Say) has been developed. The medium contains serine (0.5 M), arginine (0.05 M), leucine (0.065 M), and magnesium chloride (0.025 M); and it is more effective than host haemolymph in inducing oviposition. This completely artificial oviposition stimulant was developed to facilitate the mass rearing of the parasite on an artificial diet.