Procedures for absolute population sampling of the gallicola migrans stage of the pine leaf chermid on its secondary host are described. This involves determining the mean numbers of gallicolae per fascicle on one twig from each of 29–240 pines per stand and estimating the numbers of fascicles in the stand from the distribution of stem diameters. Patterns and distributions of the gallicolae within trees and stands are discussed with comments on their biological significance.

The juvenile hormone was necessary for the sex accessory glands in newly metamorphosed, adult males, to produce a normal amount of spermatophore material. Protein production could be restored to normal in allatectomized newly metamorphosed roaches by implanting adult or nymphal roach corpora allata. In decapitated roaches, the weight of the accessory gland is reduced drastically. The weight of the gland could be increased by implanting adult roach corpora allata, or by injecting juvenile hormone.

Immature stages of the rodent bot fly, Cuterebra tenebrosa Coquillett, from central Washington are described and illustrated. Redescription of both sexes of the adult fly are also provided. Larval cuticular spines and posterior spiracular patterns are distinctive for second instars. Important characters of third instars include shape and number of points on cuticular spines and papillae arrangement. C. tenebrosa parasitizes bushy-tailed wood rats (Neotoma cinerea) and desert wood rats (N. lepida) in the western United States and western Canada.

In four studies with loblolly pine bolts over a 2-year period, absence of the normal complement of mycangial and ectodermal fungi, or absence of mycangial fungi alone, caused a significant decrease in number of progeny, progeny/gallery, progeny/cm of gallery, and ratio of increase of Dendroctonus frontalis Zimmerman. Initial emergence of progeny was delayed 13 to 24 days. Absence of fungi had no effect on number of successful attacks, length of ovipositional gallery, and number of egg niches/cm of gallery.

Aggregation sites for male Cuterebra grisea Coquillett were found near areas where deermice were infested by botfly larvae. At these sites which were near streams or roadsides, male C. grisea flew over heat-reflecting surfaces which often contained objects taller than their surroundings. Each male chased intruders, including other males, from a territory over which it flew at regular intervals in an oval or figure-of-eight pattern. They flew in mornings during July and August provided the shade temperature was above 19.5°–20 °C and the sun was shining or had been shining. On very warm mornings when 20 °C was reached early in the morning, males did not fly until about 33/4–4 hours after sunrise. Flight almost always ended by midday. Female flies were rarely seen because they appeared only long enough to be mated. The data on C. grisea led to the discovery of similar male aggregation behavior of the pack rat botfly, C. tenebrosa Coquillett.

This study provides information on the species of Chrysocharis (Kratochviliana) found in North America with special emphasis on the Canadian species attacking the birch casebearer, Coleophora serratella (L.) (= fuscedinella Zeller), and the birch leafminer, Fenusa pusilla (Lepeletier).

The genus Chrysocharis Förster in North America north of Mexico consists of two subgenera, Kratochviliana Maláč and Chrysocharis s. str. There are 15 Nearctic species of Kratochviliana, of which 10 species are described herein as new. These are: C. (Kratochviliana) robusta n. sp., C. (K.) incerta n. sp., C. (K.) stipitis n. sp., C. (K.) hirsutiventris n. sp., C. (K.) walleyi n. sp., C. (K.) protolithocolletidis n. sp., C. (K.) milleri n. sp., C. (K.) aluta n. sp., C. (K.) coptodiscae n. sp., and C. (K.) cuspidigaster n. sp. Relationships and distribution of species-groups in North America and Europe are discussed. Keys to subgenera and species and host records are included.

Field tests were continued during 1970, 1971, and 1972 in southwestern Ontario to evaluate experimental and registered insecticides for control of Euxoa messoria (Harris) larvae on tobacco. Insecticides were applied before planting as broadcast applications to the rye cover crop or to the soil.

Of 10 chemicals tested, chlorpyrifos, leptophos, and N-2596 (S-(p-chlorophenyl O-ethyl ethyl-phosphonodithioate) gave the most consistent control, and Biothion® (O,O′-thiodi-p-phenylene O,O,O′,O′-tetramethyl phosphorothioate) and methoxychlor gave variable control. Fensulfothion was slightly phytotoxic, and trichlorfon and Mobam® (benzo [b] thien-4-yl methylcarbamate) were ineffective in the present study. Supracide® (O,O-dimethyl phosphorodithioate S-ester with 4-(mercaptomethyl)-2-methoxy-Δ2-1,3,4-thiodiazolin-5-one) and Orthene® (O,S-dimethyl N-acetyl phosphoramidothioate) showed promise for control of E. messoria larvae.

Levels of reducing sugars and total alkaloids in the cured leaves were unaffected by treatment, indicating that these insecticides had no effect on tobacco quality.

Odontivalvia n. gen. is described for Noctueliopsis radialis Munroe from Texas.

A sensillum in the shape of a truncate cylindrical peg is present on the apex of the antenna in both sexes of Itoplectis conquisitor (Say). The sensilla occur in distinct fields of 19 to 38 pegs per antenna in males , and 26 to 35 pegs per antenna in females (x = 30.6). The pegs measure 1 to 15 μ, in height in males and 4 to 13 μ in females, and 2 to 6 μ in diameter in males and 2 to 5 μ in females. Pegs in the inside ranks at the very tip of the antenna are shorter than those in outside ranks which are more subterminal in position. This height variation results in the flat to slightly concave tips of the pegs being aligned on approximately the same plane. Innervation was confirmed by light microscope observations of sectioned material. The placement of the pegs at the antennal apex suggests that they perceive stimuli in the act of antennal tapping.

An epizootic of Entomophtora sp. was observed in a population of Cinara curvipes Patch. of an exceptional density in a young stand of Abies balsamea L. (Mill.). The presence of Entomophtora and the epizootic were determined in the field by observing resting spores with a portable mini-microscope and by estimating the number of dead or liquefied aphids.

The fungus attacked most of the aphids. Among the few living females observed in October, only those that did not contain resting spores were able to reach the ground for protection. Observations conducted in the same stand the following year indicated that the epizootic of Entomophtora sp. was responsible for the reduction of C. curvipes in the observed stand.

Chemical studies utilizing colour tests, gas chromatographic and mass spectrometric analysis have shown that hydrogen cyanide and benzaldehyde are constituents of the defensive secretion of the polydesmoid millipede Apheloria coriacea (Koch).