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.

The egg and five nymphal instars of Plagiognathus medicagus Arrand, a pest of alfalfa in Western Canada, are described and illustrated. A key for ready separation of the nymphal instars is provided.

The following suggestions in use of family-group names for eriophyoid mites are made in accordance with the International Code of Zoological Nomenclature. (1) The name Sierraphytoptidae Keifer 1944 should have priority over Nalepellidae Roivainen 1953 sensu Newkirk and Keifer (1971). (2) The name Diptilomiopidae Keifer 1944 should have priority over Rhyncaphytoptidae Roivainen 1953 sensu Keifer (1961). (3) The superfamily concept of Shevchenko (1968, 1971) should take the name Nalepelloidea Roivainen 1953 rather than Trisetacoidea (a justified emendation of "Trisetoidea") Shevchenko 1968. (4) The names Nalepellidae and Nalepellini should take Roivainen 1953 as author rather than Newkirk and Keifer (1971). (5) Similarly, the names Sierraphytoptini Keifer 1944, Mackiellini Keifer 1946, Diptilomiopinae Keifer 1944, and Trisetacini Shevchenko 1968 should retain their authors and dates as first proposed for new family-group taxa, rather than being new taxa as proposed by Newkirk and Keifer (1971).

Hydraulic, fan-spray nozzles (Teejet 650067) at 50.8 cm (20 in.) spacing, 55.9 cm (22 in.) above the target surface, and operating at 2.8 kg/cm2 (40 p.s.i.) produced very uneven coverage when applying aqueous sprays containing uranine. Deposits immediately below the nozzles were 2 to 3 times more than those between nozzles.

Deposits on grasshoppers (Melanoplus sanguinipes F.) were directly proportional to their plan area. Since this area increases as the square of the linear dimensions and weight increases as the cube, second instar grasshoppers collected twice as much spray/unit weight as fourth instar nymphs and 3 times as much as adult females. These differences were reflected in the mortality caused by insecticide sprays. A spray applying dimethoate at 140 g/ha (2 oz/ac) in 39.3 l./ha (3.5 Imp. g.p.a.) killed 90% of second instar nymphs but only 14% of adult males.

Xylem sap tension, an indication of moisture stress, was compared in foliated twigs of white fir infected by the mistletoe, Phoradendron bolleanum subspecies pauciflorum, and in paired, uninfected fir at the lower, mid-, and upper crown level. The upper boles were examined for fir engraver attacks. Reproductively successful attacks containing little or no host oleoresin were found in the infected fir, while only a single unsuccessful attack filled with oleoresin was found in the uninfected trees. Mean moisture stress in the upper crowns of most of the infected fir exceeded that in uninfected trees in all paired comparisons except one with a light infection. No differences in mean moisture stress between infected and uninfected trees were found at the lower and mid-crown levels.

Pemphigus spirothecae Passerini, a member of the subfamily Eriosomatinae, was collected in large numbers from spiral galls on lombardy poplars in Quebec during 1972 and 1973. This aphid is well known in Europe but has not been reported previously from North America. It has a monoecious life cycle.

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.

Several Schmitt boxes of previously unplaced Platygastridae were made available to me through the kindness of Dr. Paul Marsh, U.S. National Museum. This is the first in a series of papers describing new species and illustrating the types from these and from previously described species.

Perilampus salicetum Steffan (Chalcidoidea) is removed to the monotypic Steffanolampus (gen. nov.). The type series was dubiously reported as being taken in either Austria or the Far East but the species has been subsequently found only from Quebec to Maryland and Michigan, as well as in Washington State. It is associated with several anobiid beetles.

The Nantucket pine tip moth, Rhyacionia frustrana (Comstock), and the pitch pine tip moth, R. rigidana (Fernald), often occur together in young stands of southern pines, but the former is more common.

Mites collected from 69 Larus delawarensis Ord nests on Granite Island, Lake Superior, northwestern Ontario, during the summers of 1972 and 1973 showed phenological relationships with the breeding cycle of the gulls. The populations of five selected mite genera varied in relation to nest initiation, egg laying, and egg hatching periods of the gulls. Moisture within the nests significantly affected mite population densities, whereas nest density did not.

Platygaster taylori n. sp., reared from blackberry stem galls, is described, compared with similar species, and a list of Platygasteridae associated with blackberry in the United States of America is given.

A review of studies of mayfly fecundity (number of eggs produced per life span) indicates that some of the larger mayflies, e.g. Palingenia and Hexagenia, have total potential fecundity values that are higher than found in most other insect groups. For 12 mayfly species of a brown-water stream in Alberta, Canada, fecundity of the subimagoes was generally predictable from the size of the female regardless of the particular species. An exception was Leptophlebia cupida, which, for a given length, had a much higher fecundity than any of the other species and a much larger increase in fecundity per unit increase in body length. L. cupida averaged 362 eggs/mm body length, while the other species had an average egg production of between 100 and 200 eggs/mm body length. The small species, although having a relatively low total fecundity, produced more eggs per unit volume of abdominal space than did the larger species. By combining quantitative emergence data and fecundity data, we calculated that the entire mayfly fauna produced about 300,000 eggs/m2 per year and that it takes an average of 934 eggs to produce one subimago of the next generation.

Corethrella brakeleyi (Coquillett), a haemophagous chaoborid, is recorded for the first time in Canada. Among the insects associated with the larvae of C. brakeleyi was Culiseta melanura (Coq.), a new addition to the mosquito fauna of Quebec.

A second specimen of Holcopsis fenestrata Enderlein, previously known only from the type and with the locality in question, is reported from Mexico. Some diagnostic and comparative characters of the species are noted.

Three types of traps were tested in 1969 and 1970 for collecting pupae of the eastern hemlock looper, Lambdina fiscellaria fiscellaria (Guen.). Highest numbers of pupae were obtained with burlap traps made from 2-ft-wide bands wrapped around trunks of infested trees. The proportion of the pupae in the burlap traps was estimated. Some of the potential uses for pupae collected by the method are mentioned.

The addition of copper to an artificial diet improves growth and survival of the house cricket, Acheta domesticus (L.), the optimum concentrations being 2 μg/g for females and 10 μg/g for males. This sex difference in requirements is attributed in part to the accumulation of copper by the larval testis. Adult males showing a loss in pigmentation, the so-called ’albino’ males, are obtained on diets low in copper; the percentage of ’albino’ males is increased by the addition of vitamin E to the diet. The pigmentation effect of vitamin E is explained by movement of copper into the testis, the development of which is stimulated by vitamin E.

Field tests demonstrated the attractiveness of several compounds to the olive fly, Dacus oleae Gmel.; a correlation with far infrared absorption bands was derived; and dl-homocysteine thiolactone hydrochloride was tested because of its conformity with this pattern. Field tests confirmed the predicted attractiveness of this and a few other compounds, and also an anti-attractant property in menthol and in butyl butyrate.

H. Mourier (1965) described a “novelty effect” in the response of houseflies, Musca domestica L., to a “new object” (usually a 15×15 cm square black tile) placed on the floor of their cage. On its first introduction into their familiar environment, the tile appeared highly attractive and received many visits. The number of visits thereafter decreased and approached a constant level after about 20 min. If the tile was then removed and replaced after an interval of less than 5 min there was no novelty receptivity, but this gradually returned as the time the tile was out of the cage was more and more extended. After 40–60 minutes the response was equal to the “new object” attractiveness. The flies did not seem to miss the tile when it was removed (Mourier, pers. comm., 1971).