A survey of the phytophagous arthropod fauna of the introduced legume crownvetch, Coronilla varia L., was conducted in Pennsylvania during 1971–73. Samples were taken from large forage fields, highway plantings used for erosion control, and greenhouses. Emphasis was placed on determining what known pests of other forage legumes are associated with crownvetch and on clarifying the relationship of the species to the host plant. Species were categorized as primary, secondary, and incidental according to their intimacy with the host. Biological notes, known host plant range, and association with other legumes are presented for 19 of the 33 primary species. The grasshoppersMelanoplus differentialis (Thomas) and M. femurrubrum (DeGeer) and the gelechiid moth Stomopteryx palpilineella Chambers caused defoliation in several highway plantings. Other abundant species were the alfalfa plant bug, Adelphocoris lineolatus (Goeze); potato leafhopper, Empoasca fabae (Harris); clover stem borer, Languria mozardi (Latreille); and nitidulid beetle Meligethes nigrescens Stephens. The similarity of the phytophagous fauna of crownvetch to that of alfalfa is discussed. Alfalfa pests found not to breed on crownvetch were the meadow spittlebug, pea aphid, alfalfa weevil, clover leaf weevil, clover root curculio, and alfalfa seed chalcid. As yet pest problems on crownvetch are few when compared with those of alfalfa and other forage legumes.

Field studies conducted in cherry orchards of the Willamette Valley, Oregon, indicate that diapausing pupae of the western cherry fruit fly, Rhagoletis indifferens Curran, overwinter in the soil at a depth of 1–4 in. Relatively very small numbers of pupae were collected from surface debris and soil samples taken at a depth of 6 in. and below. The number of flies emerging from different soil depths indicated that removal of the top 6 in. of soil caused a 99% reduction in adult emergence, while the removal of the top 1 in. of soil had no effect.

Arthropod population densities were evaluated from nests of colonial ring-billed gulls (Larus delawarensis). Each nest was considered as being an island microhabitat in which a measurable population was concentrated. Despite significantly greater numbers of arthropods in larger than in smaller gull nests, population densities per nest dry weight were similar.

All codling moth larvae, Laspeyresia pomonella (L.), in 100,000 infested apples were killed by fumigation with 32 g/m3 methyl bromide for 2 h at about 17 °C followed by 31–35 days of storage at −0.5 °C. The apples were harvested into bins, fumigated, and placed in a standard cold storage room of a grower’s packinghouse as would be done under commercial conditions. Standard cold storage killed all first and second, and some third, instar larvae in nonfumigated fruit. Cursory sampling indicated that fumigation alone, without subsequent cold storage, could kill all stages. The fumigation and storage treatment did not injure Red Delicious, Golden Delicious, Spartan, Jonathan, or Newtown apples.

Although the species that were closely related had similar adult feeding habits, they varied in their specific dietary requirements for mating and for the initiation of oviposition. In Chrysopa lanata, which is not predacious in the adult stage, the females required a protein-carbohydrate diet in order to mate; on the other hand, Chrysopa downesi males and females, which also are not predacious, mated when fed a diet consisting only of sugar and water. Chrysopa nigricornis males and females both required prey (Myzus persicae) before they would mate; whereas Chrysopa quadripunctata and Sympherobius amiculus, both of which are predacious as adults, did not need a diet other than sugar and water for mating.

All five species depended on prey or a synthetic protein-carbohydrate diet for sustained oviposition; however, S. amiculus initiated oviposition when fed only sugar. When the synthetic protein-carbohydrate diet was substituted for prey, 40% of the C. quadripunctata females began to oviposit. The same diet did not promote oviposition in the predacious C. nigricornis adults.

The triglyceride fatty acids of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopk., were studied 0–21 days during the beetle’s reproductive period. Fatty acids present were identified as myristic (14:0), palmitic (16:0), palmitoleic (16:1), stearic (18:0), oleic (18:1), and linoleic (18:2). Palmitic acid increased from 12 to 23%, while palmitoleic decreased from 15 to 6% of the total triglyceride fatty acids during reproduction. Oleic acid was the predominant fatty acid in both sexes (approx. 65%) and formed 55% of the fatty acid moiety of the egg triglycerides.

Echthromorpha agrestoria pascuensis is described from Easter Island (Isla de Pascua). It is a rather melanic race of this extremely widespread species.

The new genus Dioryctriodes is described for D. daelei n. sp., from Italy. This species closely resembles Dioryctria taiella Amsel in maculation but not in palpal structure or genitalia. D. taiella is referred to a new species-group of Dioryctria.

Diurnal activity of Aedes and Culex spp. was observed near Banff, Alta., and Hope, B.C., when naturally polarized light was present, reduced, or absent in relatively open habitats. Resting mosquitoes attacked as soon as they were approached closely, whether or not polarized light was present. In contrast, mosquitoes made long, roving flights only when there was polarized light overhead. Roving flight stopped whenever zenith polarization was disrupted by passing clouds or by the unpolarized glare surrounding the sun. As overhead polarization is most intense near sunrise and sunset, it could be employed then by mosquitoes travelling to and from feeding or oviposition sites.

Random populations of field-collected Xyletinus peltatus (Harris) beetles laid significantly more eggs on yellow-poplar than on any of seven other woods placed in a crawl space beneath a house and in a controlled environment. Egg deposition of random beetle populations when confined to individual woods was generally greatest on woods most often chosen for choice oviposition, but no significant statistical preference was shown for any wood. In tests with beetles collected in copula to ensure equal representation of sexes and that mating had occurred, yellow-poplar was again preferred for egg-laying. Variability in oviposition and fewer eggs per female by beetles collected while mating suggests that these beetles may have mated and laid eggs previously. The third test, with wood of varying ages since tree felling, suggested that beetles prefer at least some woods to be aged and also indicated preference for yellow-poplar. In all three choice experiments beetles showed a significant preference for block undersurfaces for egg-laying; this preference possibly indicated responses to changing ambient light conditions. Egg-laying females appeared to respond first to favored hosts, then to block undersurfaces or oviposition site characteristics. Both host species and wood surface features would affect susceptibility to beetle attack.

Studies of the population dynamics of the Semiothisa complex in Manitoba larch bogs indicated that the fluctuations in the numbers of this complex were clearly related to mortality in the pupal stage, which is therefore a “key” stage. Density-dependent factors are evidently operating in the dynamics of these insect populations. Interrelationships exist between the various Semiothisa species and also between looper and larch sawfly numbers.

The adults of Chrysopa harrisii Fitch, which are not predaceous, overwinter in a state of reproductive diapause. During both the dormant and the reproductive periods they remain dark green, a colour apparently adapted to the species’ occurrence on conifers. Two to three generations per season are possible in the Ithaca, N.Y., area.

At 75°F, which is the optimum constant temperature for development and survival, the time from oviposition to adult eclosion is 29 days. Theoretical thresholds for development of all stages are relatively high, between 50° and 57°F, and development from egg to adult requires 566 heat degree days.

In the laboratory, the critical photoperiod for diapause induction is between LD 13:11 and LD 14:10; short days maintain diapause for approximately 45 days (at 75°F); long days terminate diapause. Both newly-emerged and reproductively-active adults are extremely sensitive to diapause-inducing photoperiods. In the field, all adults emerging on 5 September or later enter diapause and it appears that diapause induction in the Ithaca population begins in the latter part of August. Short days maintain diapause until the end of December, and neither long days, increasing day lengths, nor low temperatures play a role in hastening diapause termination in nature.

In timing its vernal reproduction, C. harrisii has evolved a strategy that combines an early-ending diapause with an apparently relatively high temperature threshold for post-diapause development. Therefore, although diapause ends around the winter solstice, heat accumulation is prevented until much later, when temperatures are relatively high.

Mountain pine beetles attacked logs, mated, and constructed egg galleries slowly at 4.4 °C under laboratory conditions. No eggs were deposited in 6 weeks. Attack and oviposition increased above this temperature.

Larvae of different initial sizes grew at the same rate throughout each test temperature from 4.4 °C to 12.8 °C. Rate of growth increased with increase in temperature. Larval growth at 2.2 °C is difficult to prove because of very high mortality among smallest individuals.

A new species of Aroga (Lepidoptera: Gelechiidae) is described, and characters separating it from Aroga trialbamaculella (Chambers) and Aroga epigaeella (Chambers) are given.

Aroga argutiola is univoltine in Michigan. The adult emerges in late May and oviposits on sweet fern (Myrica aspleniifolia L.). There are six larval instars. The larva constructs a nest by tying leaves together, and then feeding on the leaves in and adjacent to the nest. The last instar overwinters on the ground in a cocoon. The pupa appears in May.

Spruce budworm, Choristoneura fumiferana, are often naturally infected with the microsporidan parasite Nosema fumiferanae and this is frequently carried over into laboratory stock. The presence of N. fumiferanae infection seriously interferes with the study of other pathogens. The antibiotic compound Fumidil B has recently been used to control infection in Ostrinia nubilalis (European corn borer) by the microsporidan Perezia pyroustae (Lewis and Lynch 1970) and infection in Anthonomus grandis (boll weevil) by an unidentified microsporidan (Flint et al. 1972).

Frequency modulation has been discovered in the calling song of a conocephaline katydid, Conocephalus nigropleurum (Bruner). Real time sound spectrum analysis reveals a drop of 5 khz during the closing wingstroke.

Studies on population increase of the alfalfa leafcutter bee (Megachile rotundata Fabr.) were conducted in northern areas of Alberta and British Columbia (lat. 55°N. to 58°30′N.). Polyethylene shelters with one side open, placed over the domiciles, raised domicile daytime temperatures by 4°–10 °C, increased the duration of activity and the pollinating range of the bees, and resulted in an increased number of cocoons. Population increase was 2–5 times greater when hives and shelters faced south than when they faced east or west. Within a shelter bees also preferred hives with southern exposure. Movement of domiciles in mid-season for distances of 150 m or more caused a reduction in bee populations. Bees preferred wood to polystrene nesting material, old to new material, and surface stained material with patterns to unstained material. Severe mould development in polystrene nesting material affected development of larvae and emergence of pupae. Since population increase of M. rotundata, by utilization of polyethylene shelters and by proper directional orientation, is successful, re-establishment of a major alfalfa industry in northwestern Canada is now possible.