Eclosion of overwintering eggs of the European red mite, Panonychus ulmi (Koch), in Nova Scotia was studied at four constant temperatures. Days to 50% hatch were 44.8, 23.1, 12.9, and 8.8 while the rates of development were 2.18, 4.53, 7.59, and 11.34% per day at 8°, 12°, 16 °and 20 °C, respectively. Nonlinear equations were developed to estimate the time to 50% hatch of overwintering eggs as a function of temperature. A weighted average of the daily extreme temperatures was used to improve the estimated time to 50% hatch for field data from the rates of development in the constant temperature studies.

The structure and position of the spiracles in Sitophilus granarius and Tribolium confusum adults was studied. On the basis of this an attempt was made to explain the differences in water loss from these two species under reduced pressure. It was concluded that the spiracular structure combined with the inflation of the body under very low pressures, can account for the apparently anomalous water loss results.

The larvae of Tetralopha web leaves of many kinds of trees and shrubs. A key to nine North American species is included, with descriptions of the last instar larvae. The species considered are Tetralopha robustella Zeller, T. militella Zeller, T. expandens Walker, T. aplastella Hulst, T. asperatella Clemens, T. vacciniivora Munroe, T. euphemella Hulst, T. scortealis Lederer, and T. baptisiella Fernald.

Extreme differences in survival of eggs of Ctenicera destructor (Brown) were observed when eggs were placed at depths ranging from 1/2 to 4 in. in the soil in the field. These differences were closely related to the soil moisture variations recorded during different seasons. Eggs that had absorbed water before being placed in the field were much more resistant to desiccation than those that had not absorbed water.

In the laboratory, eggs absorbed water, developed and hatched in soil dried to a constant moisture level of 8.2% (dry weight basis) at 98% R.H., but were unable to absorb water from soil dried to moisture equilibrium at 96.6% R.H., or from soil wetted to moisture equilibrium at 98% R.H. Some water was absorbed by eggs placed in air at 98% R.H., but this was insufficient for normal development and hatching. The soil moisture tension of soil dried to moisture equilibrium at 98% R.H. was calculated as approximately 31 atmospheres. It is evident that eggs are able to develop remarkably high internal suctions in order to absorb water from such soil.

Both the field and laboratory results showed that in drying soil, the lower limit of soil moisture at which eggs could absorb water was about 8%, considerably below the permanent wilting percentage (9.9%) of the soil used in these studies.

In laboratory studies, suspensions of killed and live ice-nucleating microorganisms were used to decrease the supercooling capacity of the winter form of pear psylla, Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae). Dry, untreated adults supercooled extensively before they froze at −22.7 °C. Application of 1000 ppm of a preparation of the killed ice-nucleating bacterium, Pseudomonas syringae Van Hall 1902 (Pseudomonadaceae), significantly decreased the adults’ supercooling capacity causing some individuals to freeze at temperatures as high as −3.9 °C. Topical application of several live microorganisms also reduced the supercooling capacity of adults significantly; Pseudomonas putida (Trevisan 1989) was the most effective, causing more than 80% of C. pyricola adults to freeze at −15 °C or higher. Furthermore, the temperature of crystallization of adults treated with P. putida remained significantly higher than controls for at least lid post-treatment. Application of ice-nucleating microorganisms also reduced the capacity of adults to survive short-term exposure to high subzero temperatures comparable to a mild frost. Realization of this approach for biological control of pear psylla will require the development of methods for the delivery of microorganisms to overwintering adults under field conditions.

The appearance of an article “Window flight traps for insects” by Chapman and Kinghorn (Can. Ent. 87 (1): 46-47. 1955) suggests that it may be well to describe another flight trap. Specimens taken by it have been labelled “caught in cheesecloth trap”, a statement which is true but perhaps enigmatic.

While on the late Ralph Hopping's staff, the writer built a number of cages for rearing forest insects in southern British Columbia. These cages were all 6 × 6 × 6 ft., each on a cloth covered wooden platform, with a minimum super-structure of 2 × 2 in. lumber to the inside of which cheesecloth was tacked to form an insect-tight enclosure. One entered by a door on the lower part of the north or east side.

Large species; thoracic dorsum conspicuously trivittate; mesopleural membrane bare; basal section of radius bare; tibiae without bright niveous patches; fore tarsal sepments not much dilated. Female: head and thorax thickly cinereouspollinose; mouth parts adapted for biting; tarsal claws simple; posterior margin of seventh abdominal sternite with conspicuous fringe of long hairs; paraproct (anal lobe) with large, highly polished ventral prolongation; ovipositor lobes very widely separated. Male: style without apical tooth; ventral plate broadly cleft almost to base. Pupa: respirator organ with nine uniformly radiating, somewhat inflated, rather short filaments; abdominal armature lacking on fifth to seventh tergites; cocoon fabric loosely reticulate, porous, with greatly elevated opening. Larva: exceptionally long and slender, evenly expanding posteriorly, seventh abdominal segment strongly bulbous ventrally; antenna six-segmented; submentum with eight to 11 hairs on each side

Two new species of litter-inhabiting leptonetid spiders from Korea are described: Leptoneta namkungisp. nov. from Mt. Buyong, Chungcheongbuk-do, and Leptoneta kwangreungensissp. nov. from Kwangreung, Gyeonggi-do.

As our knowledge of the larvae increases, the fundamental differences between Agriotes Eschscholtz and Dalopius Eschscholtz become more apparent. However, the larval characters hitherto used to separate the genera are now known to be quite inadequate.

The North American Diparinae (Pteromalidae: Chalcidoidea) consists of six genera and 11 species, of which eight species are described as new. These are Trimicrops bilineatus, T. trilineatus, Dipara pedunculata, Netomocera nearctica, Lelaps floridensis, L. beckeri, L. melinus, and L. striatus. Illustrated keys to genera and species are provided.

The field attractivity of (E,Z)-2,13-octadecadienyl acetate (E,Z-2,13-18:OAc) (30 μg loaded on red rubber tubing) alone or in combination with (E,Z)-3,13-octadecadienyl acetate (E,Z-3,13-18:OAc) (0.9 μg added) towards the male currant borer, Synanthedon tipuliformis Cl., (Lepidoptora: Sesiidae), was compared in British Columbia (B.C.) and in Quebec (Canada) by means of trapping trial. The binary mixture attracted males in significantly higher numbers into sticky traps than E,Z-13-18:OAc alone [17.0 male captures/trap/inspection versus 1.7 in Langley (B.C.), 32.7 versus 11.9 in De Roche (B.C.), and 5.3 versus 0.2 in Ile d’Orleans (Que.), respectively]. These results suggest that the Canadian currant borer populations belong to the same strain as those in Europe and New Zealand, with E,Z-3,13-18:OAc remaining an important attractant-synergistic component.

One of the more frequently used methods of sampling flying insects is the sticky trap. These traps are often used to evaluate the type and size of prey available for aerial insectivores, such as bats and birds (e.g. Barclay 1991; Brigham 1992). Non-attractant sticky traps are favoured because they are considered relatively bias-free, yielding a more representative sample than attractant traps (Service 1976). Sticky traps are versatile in that they are simple to construct and operate, portable, and relatively inexpensive. When using these traps, it is possible to sample insects economically in similar or different habitats and at various heights within habitats (Kunz 1988).

Some interspecific and interpopulation Lepidoptera and Orthoptera hybrids show a syndrome of developmental abnormalities referred to here as the “sequence effect.” In normal within population broods of Lepidoptera males develop slightly faster than females, but in crosses showing the sequence effect, females in one direction of the cross develop faster and in the reciprocal cross much more slowly than their male siblings. In some cases the environmentally induced diapause of the females may differ strikingly from that of their male siblings. Development rate and diapause in these species appear to be controlled by a sex-linked coadapted gene complex. Expression of the sequence effect may result from a loss of a species- or population-specific balance between regulatory and secretory portions of this complex, resulting in hormonal abnormalities which are more likely to be expressed in the heterogametic sex (females in Lepidoptera, males in Orthoptera).

Four new species of the Aleiodes apicalis (Brullé) species group (Hymenoptera: Braconidae: Rogadinae) from the Neotropical Region are described and illustrated: Aleiodes ambrosiaenew species. from Peru, A. aquilesinew species from Costa Rica, and A. sachambrosiaenew species and A. tapirapenew species from Brazil. We also add new distribution records for Aleiodes molestus Cresson, from Costa Rica. With the addition of the new species, the A. apicalis species group has 11 species from the New World, six of which are recorded from Neotropical Region.

Female Culex tarsalis Coquillett trapped in CO2-baited light traps or reared from field-collected pupae were marked with fluorescent dust, released, and recaptured in traps baited with CO2 with or without light. Recaptures of trapped females peaked on the first night of recapture collections. Recaptures of reared females peaked on the first or second night when autogeny rates were low (25–44%) but 2-4 nights later when rates were high (86–88%). It was concluded that autogenous females did not seek blood until after they had oviposited, and that autogenously induced delays in feeding probably influence the extent of virus transmission by C. tarsalis.

Stretched follicular tubes indicating recent oviposition were found in 23.4% and 5.2% of empty parous females from shelters and CO2-baited traps, respectively, and in 2.3% of freshly engorged parous females from shelters. Females often failed to blood-feed until at least the second night after oviposition.

The free fatty acid composition of the southern pine beetle, Dendroctonus frontalis Zimmermann, and associated bark beetles was determined by gas-liquid chromatography. The lipid composition of several species of hymenopterous parasites matched the bark beetle hosts from which they were reared. Lipids from field collected parasites were compared with the lipid composition of possible bark beetle hosts to determine host of origin. Parasites ovipositing on a host were usually found to have a lipid composition matching that host. Approximately 20% of the parasites that were observed attempting to parasitize the southern pine beetle apparently developed on other bark beetle hosts.

Chrysops univittatus Macquart females were more abundant in late July and early August in southwestern Quebec. Dry-ice baited canopy trap collections consisted of 55% (n = 177) of the nulliparous and 77% (n = 91) of the parous females. Incidence of nectar feeding, as determined by cold anthrone test, was 73% (n = 244) and 96% (n = 268) of the females contained sperm; no difference was found between parous and nulliparous females. This species is anautogenous, and only one gonotrophic cycle was recorded following ovary dissection. Number of ovarioles was correlated with body size (as determined by wing length) by linear regression analysis.

Field studies in southwestern Quebec showed that feeding scars of the plum curculio Conotrachelus nenuphar (Hbst.), were made by overwintered and summer adults and occurred throughout the growing season. Egg-laying scars were made by overwintered adults only and occurred from the time of apple set to early August. The latter category included deep entries, which were made by the developing larvae in the fruit. In the McIntosh and Lawfam varieties feeding scars were found in 37.4 and 35.0 per cent respectively, averaging 36 per cent for the combined varieties, and egg-laying scars in 62.6 and 65.0 per cent, averaging 63.8 The extent of the two types of damage in the field appeared to be the reverse of those observed in the insectary, where feeding scars for the combined varieties averaged 63.2 per cent and egg-laying scars 36.8 per cent. In the insectary, 41.1 and 22.1 per cent of the feeding scars were respectively contributed by overwintered and summer adults. It was not possible to estimate these fractions in the field.

Mosquito-repellent chemicals tend to absorb far infrared radiation (below 600 cm.−1) more strongly than do non-repellents of comparable molecular weight. The correlation is probably less direct than was previously supposed, and is hardly strong enough to be used as a primary screening technique.