Dendroctonus brevicomis Lec. responded in flight to combinations of insect- and host-produced volatiles. Emergent female beetles crushed at −70 °C, as well as synthetic exo-7-ethyl-5-methyl-6, 8-dioxabicyclo [3.2.1] octane (“brevicomin”) attracted both sexes of the western pine beetle when offered with oleoresin freshly tapped from the host, Pinus ponderosa Laws. Offered separately, these materials were inactive. Crushed emergent Dendroctonus ponderosae Hopk. males per se, however, attracted flying D. brevicomis in appreciable numbers. Dominance of either host odor or insect pheromone appeared to govern the sex ratio of the responding insects.

Methods of trail formation and organization of group foraging by the ants Formica obscuriventris Mayr, Myrmica americana Weber, and Crematogaster lineolata (Say) were studied under laboratory conditions. Each species was able to organize group travel to a persistent food source. M. americana and C. lineolata achieved this by using trail pheromones, the former species using these pheromones only to establish the trail and the latter using them in all stages of foraging. F. obscuriventris apparently did not use trail pheromones and each individual learned the route to the food independently.

The most suitable temperature for larval development of Aedes flavescens was found to be 20 °C. At this temperature 74% of the larvae pupated in 20 days. At 15 °C the developmental period was 42 days with a survival rate of 54%. At 25 °C the developmental period was 22 days but the survival rate dropped to 7%. At 10 °C the developmental period was 80 days with a survival rate of 6%. At 5 °C and 30 °C mortality was 100% in the first instar stage. Adult males emerged from the pupae in three days at 25 °C, two days earlier than the females.

Habrobracon lineatellae Fischer has been imported from Lebanon into California in the course of a project on the biological control of the peach twig borer, Anarsia lineatella (Zeller). The navel orangeworm, Paramyelois transitella (Walker), is used as a host to mass-culture this parasite. Its biology is similar to that of other species in the genus, for the female paralyzes the host before oviposition and the larvae develop ectoparasitically. Females begin to paralyze hosts 2 to 26 days after emergence, and oviposition is initiated 1 day after they begin this host paralyzation. The number of eggs per female varies from 32 to 954. A maximum of 12 larvae of H. lineatellae can develop on 1 larva of P. transitella. When virgin females are held for 4 days and then placed with sexually active males for the rest of their lives, the sex ratio of the progeny is 53% female. The adults do not host feed. Females fed honey–water live an average of 105 days (range 51 to 166 days).

Populations of Dendroctonus ponderosae Hopk. aggregate on pine trees in response to a combination of host- and insect-produced volatiles. Release of the insect-generated volatiles by defecation coincides with the release of host volatiles as resin exudes from the galleries initiated by the female beetles. When tested with oleoresin under field conditions, synthetic trans-verbenol, the major insect pheromone, was highly attractive to both sexes of D. ponderosae. Also, emergent female Dendroctonus brevicomis Lec. and Dendroctonus frontalis Zimm. crushed to powder at −70 °C were attractive; emergent females of both species are known to contain large amounts of trans-verbenol. Trans-verbenol per se, however, was not attractive to walking or flying D. ponderosae.

A field investigation was carried out in Chatham, Ont., to evaluate the oviposition preference and survival of Hylemya brassicae (Bouché) on six early cruciferous crops, namely, Brussels sprouts, broccoli, cabbage, cauliflower, Chinese cabbage, and kohlrabi. A significantly greater number of eggs was laid on Chinese cabbage than on any other host. In the first generation, the percentage mortality for each of the life history stages differed significantly on the various crucifers but the total generation mortality did not.

Fourteen insecticides were tested by direct contact against second-instar nymphs of a grasshopper, Melanoplus sanguinipes F. Of these, seven were judged to be sufficiently promising to be compared for toxicity and persistence as deposits on wheat seedlings. Comparison with a dieldrin standard showed that Dursban, Dibrom, and malathion were extremely effective by contact but had little persistence on growing wheat. Baygon was extremely effective by contact and showed some persistence. CIBA 9643 and dimethoate were the only two compounds to show persistent effects almost equivalent to dieldrin, and CIBA 9643 was more toxic than dieldrin by direct contact.It was concluded that CIBA 9643 was the only compound, of those tested, which might give grasshopper control equivalent to, or better than, dieldrin or the currently recommended dimethoate.

Newly emerged adults of Dendroctonus pseudotsugae Hopkins were separated into pairs of similar size. One beetle from each pair was used as a control; the other was flown on a rotating mill. Soxhlet extractions in petroleum ether revealed that the flown beetles contained significantly less fat.

The unique habits of a jack pine needle-miner, Eucordylea canusella (Free.), are described. It feeds for the greater part of its life on dead or dying needle tissue and on the fungus Aureobasidium pullulans de Bary (Arnaud), which grows within the needle-pair following construction of a mine by the first-instar larva. On reaching maturity, the larvae revert to a more conventional needle-mining behaviour. This habit is unusual in defoliating Lepidoptera although other species in the same, or closely related genera, are also thought to feed upon fungi. The impact of these findings on the taxonomy of Eucordylea spp. is discussed.