The sexes of all but three of the North American species of Ips DeGeer can be separated reliably using characters on the frons, vertex of the head, protibiae, or declivital armature. In general, these secondary sexual characters are consistent within Hopping’s species groups.

Observations mainly on sexual behavior were made in both the field and laboratory on five species representing four genera of stag beetles all occurring in central Illinois.Males of Lucanus Scopoli (= Pseudolucanus) and Dorcus MacLeay which have relatively short mandibles made direct use of these appendages in subduing and maintaining the female in position during mating.Males of Platycerus Geoffroy and Ceruchus MacLeay which have larger mandibles did not use these appendages to hold the female, but rubbed a pair of legs intermittently against the female’s elytra and had much longer matings.The presence of a female stimulus was determinant in the amount of fighting among males.

The last three larval instars of each of the 25 species of mosquitoes reported from New England have, with very few exceptions, been studied. Characters useful in separating the larval instars of Aedes are discussed, and a key to differentiate the four larval instars, regardless of species, is presented. By making use of characters constant in all instars of a species, and by noting variations between and within instars, a key is presented which should permit the identification of most New England Aedes material, mounted or unmounted, in any of the final three larval instars.

The following new pyraustine taxa are described: Callibotys n. gen., type-species Rhectothyris hyalodiscalis Warren, from Assam and Burma, including also Crocidophora carapina Strand, from Taiwan, considered a distinct species from Callibotys hyalodiscalis, and Callibotys wilemani n. sp., from Honshu, Japan; Eumorphobotys n. gen., type-species Calamochrous eumorphalis Caradja, from China, and also including Calamochrous obscuralis Caradja, from China; Sinibotys n. gen., type-species Crocidophora hoenei Caradja, from China.

In laboratory experiments at Belleville and Guelph, Ont., four species of coccinellids, Cycloneda munda (Say), Adalia bipunctata (L.), Coccinella transversoguttata richardsoni Brown, and Coleomegilla maculata lengi Timberlake, revealed strong attractances to Juniperus virginiana L. (juniper) for oviposition. This attractancy was due to the specific odour of Juniperus wood. Egg laying rates were not affected by distances up to 70 cm in laboratory cages in a greenhouse where temperatures ranged from 24.0° to 29.5 °C. This phenomenon may be used to aggregate ovipositing coccinellid females in places where aphids are expected to occur in damaging numbers.

In a 3-year study, one annual application of a 10% granular formulation of disulfoton in the soil at a rate of 2 lb actual toxicant per acre controlled M. persicae throughout the entire period that aphids were most prevalent in pepper fields. Some control was observed within a few days of treatment, but effective control did not occur until 2 to 3 weeks after placement of the insecticide. Irrigation increased the initial uptake of disulfoton, but after 2 weeks the degree of control was essentially the same in irrigated and nonirrigated plots.Analyses of fruit samples from treated plots showed that there were no detectable amounts of disulfoton or its oxidation products 42, 50, and 60 days after treatment. These observations suggest that the required interval of 90 days between treatment and harvest could be reduced. Appreciable amounts of the insecticide or its oxidation products were present in the leaves on all sampling dates.

Cepegillettea viridis new species is a large green aphid known only from swamp or low birch, Betula pumila L., in Ontario. Its relationships with the other known species, myricae (Patch) and betulifoliae Granovsky, are noted and a key to species is given.

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.

Aedes vexans (Meigen) eggs which lose water under conditions of constant atmospheric saturation deficiencies, gain water when transferred to a saturated atmosphere. Water loss is influenced by age. At relative humidities of 80% and 50%, and temperatures of 10° and 21 °C, eggs that were 28 days old lost less water than eggs 14 days old. Eggs which lost up to 34% of their weight through desiccation regained 91% of lost water within 3 days in a saturated atmosphere. Embryos remained viable. Eggs which lost 68% of their original weight in water were rendered inviable and only regained 33% of the loss in a saturated atmosphere.

Glucose, fructose, and sucrose were the only sugars detected in inner bark treated with a southern pine beetle–microorganism complex and two beetle-associated fungi. Treatments drastically lowered the reducing-sugar level. Storage of untreated bolts had no effect on reducing-sugar level; sucrose was lowered but not as much as in treated tissue. Starch content remained unchanged in all treatments.

The "pars stridens–plectrum" terminology of stridulatory organs is discussed. A list of 77 species of Scolytidae known or presumed to bear stridulatory structures is presented. The three types of scolytid stridulatory organs, vertex–pronotal, gula–prosternal, and elytra–abdominal tergites, are described and discussed.All North American species in the genus Ips were examined for stridulatory organs. The gula–prosternal type was found on females, and possibly males, of I. concinnus (Mannerheim) and I. mexicanus (Hopkins). The vertex–pronotal type occurs on females of 14 other species. No stridulatory structures were found on either sex of the remaining 17 Ips species. Females of 15 of the 18 pine-infesting species have stridulatory organs, while 14 of the 15 spruce-infesting species apparently lack them. Female I. confusus (LeConte) stridulate when entering the male entrance tunnels. Removal of the stridulatory organ has two effects: males do not permit some of these non-stridulating females to enter, and they deny entry to others for an unusually long period of time.Possession of a stridulatory apparatus in the Scolytidae appears to be associated with the sex opposite to that which initiates the entrance tunnel.No significant differences were found between gallery systems constructed by female I. confusus with the stridulatory organ removed and those constructed by stridulating females except that more single stridulating females excavated two or more egg galleries from a nuptial chamber.

Results of a qualitative survey of some digestive enzymes of sixth-instar larvae of the pale western cutworm are reported. An extract prepared from the mesenteron (midgut) and its contents showed activity for the enzymes, proteinase, aminopeptidase, dipeptidase, amylase, α-glucosidasc, α-galactosidase, and lipase. There was also evidence for a β-glucosidase activity in the brei prepared from the mesenteron. A brei of salivary glands showed activities for α-glucosidase and amylase, as well as a strong proteinase. These enzymes were not found in brei prepared from the stomodaeum (foregut) or proctodaeum (hindgut). There was no evidence for polygalacturonase, celiulase, β-galactosidase, or carboxypeptidase in any part of the digestive system.Values of pH for extracts from the different parts of the digestive system were: proctodaeum, 7.2; mesenteron, 8.2; stomodaeum, 7.8; and salivary glands, 7.8.

The uric acid content of the fats and the whole organism was determined by the Technicon spectrocolorimeter method for all instars of healthy and nuclear-polyhedrosis-infected larvae of Neodiprion swainei Midd. The results obtained revealed that (a) in healthy larvae the uric acid content gradually increased from 20 to 470 p.p.m. from the first to the fifth instar inclusively and (b) in virus-infected larvae the uric acid content was always greater than in healthy larvae. It increased from 21 to 493 p.p.m. from the first to the beginning of the fourth instar, reached a maximum of 830 p.p.m. at the end of the fourth instar, and decreased to 680 p.p.m. at the fifth instar.

The alder bark beetle, Alniphagus aspericollis (LeConte), is bivoltine on Burnaby Mountain, B.C. The principal spring attack occurred in May and the second generation attack from mid July to early August. Mature adults overwinter in shallow galleries underneath the bark while larvae, pupae, and callow adults overwinter in the brood galleries. Sporadic emergence occurred in warm periods throughout the winter but the first egg galleries were not observed until early March. Windfalls and standing trees were attacked.Adult sexes can be distinguished by the fused (female) or separate (male) seventh and eighth abdominal tergites. Females attack the host first and are soon joined by the males. Single egg galleries extending about 8 cm parallel to the length of the bole are most common. Eggs are laid on both sides of the gallery; the larvae mine outward at right angles to the egg gallery and then usually up or down the bole. Adult gallery construction and oviposition and larval mining habits were observed through plexiglass–bark "sandwiches," and are similar to those in the genus Ips. Pupation occurs in a chamber in the inner bark. Maturation from egg to callow adult required a minimum of 8 weeks.

During 1965–67, the seasonal history and habits of two oak bark beetles, Pseudopityophthorus minutissimus (Zimm.) and P. pruinosus (Eichhoff), were studied in 47 oaks, Quercus spp., in southern Ohio.All study trees were attacked and the male beetles made initial entry into the trees. The attack period per tree was usually 1–3 days, and the density of attack varied from 5 to 120 galleries 1 ft2 of surface area. Oviposition began as soon as egg gallery construction began, and the incubation period was about 5 days in the summer. The rate of egg gallery construction was about 0.2 in./day in mid-summer. The average length of the egg galleries was 1.9 cm and the average number of eggs per gallery was 41.5. Over 50% of the parent adults of both species re-emerged after egg gallery construction and oviposition. The re-emerging parent adults can attack, lay eggs, and re-emerge three times. The larval stage can last 25–247 days, the pupal stage 15–139 days, and the adult stage 7–198 days. The beetles can overwinter in every stage but the pupal stage. Spring emergence occurred 29 April in 1966 and 14 April in 1967, and in southern Ohio, two generations and a partial one occur each year.Trap trees were attacked 7–205 days and brood emergence lasted 58–329 days. The beetles can attack one tree three times.

Enoclerus barri Knull occurs in western North America from British Columbia south to Mexico and throughout the Rocky Mountain region. Adults were collected at Grass Valley, Calif., from May to September at traps baited with beetle attractants. Collections occurred at temperatures ranging from 22.5° to 31 °C; the sex ratio of trapped beetles was 4.5 females to 1 male. Duration of life cycle stages at 24 ± 2 °C were: egg, 9 days; larva, first iastar, 14 days; second instar, 12 days; third instar feeding stage, 14 days. All larvae reared to third instar failed to pupate in the laboratory. Adult females of unknown age when collected lived from 10 to 131 days and produced an average of 389 eggs per female. Enoclerus barri utilized six species of Scolytidae as hosts in the laboratory.

Extracts of free amino acids from six species of ants (Pogonomyrmex barbatus (F. Smith), P. occidentalis (Cresson), Tapinoma sessile (Say), Camponotus pennsylvanicus (DeGeer), Conomyrma pyramica (Roger), and Novomessor cockerelli (E. André) were analyzed by thin layer, one and two dimensional paper chromatography, and an automatic amino acid analyzer to determine the potential use of qualitative and (or) quantitative data of the free amino acid composition of ants in taxonomic studies. The results demonstrate that no significant qualitative differences exist, but that the automatic amino acid analyzer may be used to show significant quantitative differences in the free amino acid composition of the ants studied.

Cytoplasmic polyhedrosis viruses are, in general, more infectious to spruce budworm, Choristoneura fumiferana (Clemens), and forest tent caterpillar, Malacosoma disstria (Hübner), than the nuclear polyhedrosis viruses which affect these insects. The cytoplasmic polyhedrosis viruses interfere with and retard development of the nuclear polyhedrosis viruses.Larvae of both insects, as they grow older, develop resistance to both viruses. Resistance develops more rapidly and to a greater degree against the nuclear polyhedrosis than against the cytoplasmic polyhedrosis viruses.The nuclear polyhedrosis viruses are more lethal than the cytoplasmic polyhedrosis viruses, and all larvae infected with the nuclear polyhedrosis viruses die except those infected so late in larval development that they are able to pupate. Most young larvae infected with the cytoplasmic polyhedrosis virus die or are seriously affected, but infection has progressively less effect as the larvae mature.