Examples of the emphasized importance of larval life better than that furnished by the subfamily Gomphinæ of Odonata are few even among insects. The nymphs live under the sediment (mostly organic debris) which falls to the bottom of ponds and streams. They are aquatic burrowers which live at such slight depth that their anal respiratory orifice is never beyond the reach of clean water. This thin stratum, which forms their home and which they only leave to transform, is one of great biologic richness. In it they have found room for development in enormous numbers and necessity for extreme specialization. They are, at least when well-grown, among the more powerful members of its teeming hidden population. The imagoes emerge, flit about under cover for a few days, lay their eggs and die. They emerge largely by daylight and are subject to great decimation of numbers at this time, and are sought later by numerous powerful enemies. The females which live to oviposit lay a very large number of eggs. A female of Gomphus fraternus laid for me in a watch glass of water over 5,000 at one time. The imagoes of the ancient genus Gomphus are regarded as a race of weaklings. Their nymphs, on the contrary, are splendidly equipped for the battle of life. And it is to the perfection of their adaptation that the prevalence of Gomphines with us is due.

The genus Zacremnops Sharkey & Wharton is erected to include 2 New World species formerly placed in Megagathis Kriechbaumer. Phylogenetic relationships between Zacremnops and selected genera of Agathidinae are briefly discussed.

Using gas chromatography and gas chromatography – mass spectrometry analyses of sex pheromone gland volatiles, we identified E- and Z-11-tetradecenals (E:Z-11-14:Aid) in an 85:15 blend of E:Z as the primary sex pheromone components of Croesia semipurpurana (Kearfott). Similar chemical analyses of sex pheromone gland extracts indicated the presence of the congeneric acetates (85:15 E:Z-11-14:Ac) and their saturated analogue (14:Ac); in addition, 85:15 E:Z-11-14:Alds were present at 5% of the acetates. The E:Z-11-14:Alds alone elicited trap capture; admixtures of saturated and unsaturated acetate analogues exhibited no significant synergistic or inhibitory effects. PVC rods with an 85:15 E:Z-11-14:Ald blend is recommended as a trap bait for monitoring population trends. It is unknown whether or not the components identified here represent the complete pheromone blend of this species; data from traps suspended 1.5 m above the ground versus those suspended 10 m above the ground suggest that future field studies may need to be conducted with traps positioned in the tree canopy.

Mamestra ascula, n. sp.— Ground colour very pale ashen gray, with a somewhat luteous tinge more or less obvious in most specimens; best marked in the male, most frequently wanting in the female. The ordinary lines are all broken and obscured by the shading, yet all distinctly traceable, geminate, one part of the line blackish, the other smoky and always partly incomplete. Basal line usually marked by a geminate spot on costa. There is a short black basal streak, best marked and a little curved in the female, and above it the basal space tends to be a litter paler.

Lamenia Californica, n. sp.

Form and size of L. vulgaris. Black, shining, densely pruinose; head, pectoral pieces, and legs fulvos. Length, 4 mm.

Front but little wider across the middle than next the vertex. Head fulvous, tinged with brown on the vertex, apex of the clypeus, margins of the cheeks, and on the front each side of the central carina. Eyes dark brown. Pronotum fulvous, more or less embrowned on the disc; propleura, base of the intermediate femora and the claws dusky or blackish.

A sampling plan for the estimation of the number of achenes damaged by the red sunflower seed weevil, Smicronyx fulvus LeConte, is useful in evaluating the efficiency of weevil management strategies. The objective of this study was to determine the distribution pattern of the damaged achenes that would allow the development of a fixed-sample-size plan for estimation of the damaged achenes. Taylor’s power law and Iwao’s patchiness regression were used to analyze the distribution pattern of the damaged achenes. Slopes from both models were >1, indicating an aggregated spatial pattern. The intercepts and slopes from both models were used to calculate the minimal mean number of damaged achenes per sunflower head that can be estimated for a given sample size and precision level. If the mean number of damaged achenes per head is low (<20), the plan developed using the parameters of Taylor’s power law requires significantly more samples than the plan using the parameters of Iwao’s patchiness regression to estimate the same density of damaged achenes. If the mean number of damaged achenes per head is high (>30), the two plans give similar results. If both low and high damage situations are considered, Taylor’s plan is preferred to Iwao’s plan. At the 0.10 precision level, Taylor’s plan requires approximately 40 samples (heads) to estimate a mean of about 200 damaged achenes per head (≈ current economic injury level).

Three of the species of Ablautus Loew described here have been on hand for several years and, as no additional material has become available, there seems to be no reason for delaying their description longer. These small robber flies inhabit the more arid regions of the West and Southwest and seem to prefer sandy localities in the sage brush. Osten Sacken commented on the fact that Ablautus mimus O. S. was associated with Lestomyia sabulonum O. S. on sandy soil and seems to mimic it; and Melander says, regarding Cyrtopogon ablautoides Mel., “The species presents a curious superficial resemblance to Ablautus mimus O. S., with which it is associated in the sandy desert region.”

Acanthomola pubescens, a new genus and species of Heptageniidae (Ephemeroptera), is described from larvae collected in Saskatchewan and Alberta. Acanthomola superficially resembles Bleptus, Epeorus, and Raptoheptagenia, but differs from these genera, and all other heptageniids, in the structure of the mandibles and maxillae. The molar area of the mandible is greatly reduced and bears only a few stout spines. The crown of the maxillary galea-lacinia is rounded and lacks setae near the apex. The apical segment of the maxillary palpus is long, slender, and bare. Generic and specific descriptions of the larva of A. pubescens, gen. nov., sp. no v., are given, along with biological notes. Acanthomola appears to be a very primitive heptageniid, related to Bleptus, Epeorus, and Ironodes. It is probably most closely related to Spinadis.

It is often important to the successful conclusion of insect field-studies to know the air temperatures which govern insect activities, particularly the minimum temperature at which flight occurs. In the field, this is usually a matter of continued observations on the relative abundance of a species, correlated to some degree with observations on the air temperatures at the times of abundance or of flight.

Wheat midge, Sitodiplosis mosellana Géhin (Diptera: Cecidomyiidae), is an invasive pest of wheat, Triticum spp. (Poaceae), in North America and is found in all wheat-growing regions of the world. Wheat midge biology, particularly post-diapause emergence of adults, varies with geographic region. The biology of wheat midge has not previously been examined in the northernmost area of its range in Canada – the Peace River region of Alberta. Wheat midge adult emergence was compared in situ to two phenological models of wheat midge emergence developed in other geographic regions. In-field adult emergence did not match the published phenological models. In the Peace River region, adults emerged later than are predicted by both models and precision for both models was low. With the Saskatchewan model, accumulated rainfall that was more than 110 mm in May and early June delayed emergence, whereas accumulated rainfall that was less than 43 mm during that period caused earlier than predicted emergence. Multiple peaks of wheat midge emergence, up to 20 days apart, were observed at some sites, supporting the Jacquemin model depicting “waves” of emergence. Including differences in soil temperature accumulation related to precipitation and optimising the model temperature thresholds would improve accuracy of the current Canadian phenological model in the Peace River region.

The calling of female blueberry spanworms occurs primarily during the first few hours of the photophase under controlled laboratory and field conditions. Peak calling occurred 2 h after lights-on at laboratory test temperatures of 20,15, and 10 °C under a light:dark regime of 16:8; duration of calling was prolonged at 10 °C. Under continuous scotophase, female calling activity free-runs at a natural periodicity of ca. 27 h. However, under continuous photophase the circadian rhythm is damped to a low level of activity but maintains a ca.24-h periodicity.

The phenomena of aestivation and overwintering of ants present a most interesting study. The similarities between the two as well as their many differences offer excellent comparisons. Little work has actually been accomplished with ants in this field in spite of the studies of arthropod hibernation instigated by Holmquist (I) and others. The purpose of this paper is to present some of the more important physical and biotic factors involved in the aestivation and overwintering periods of the Occident ant. Pogonomyrmexoccidentalis Cresson, in a portion of the Northern Desert Shrub region, near Twin Falls, Idaho.

A rearing study of egg and larval parasitoids of hemlock looper (Lambdina fiscellaria (Guenée); Lepidoptera: Geometridae) was undertaken during an outbreak of this pest in Labrador, Newfoundland and Labrador, Canada. Six parasitoid species were found: Telenomus coloradensis Crawford and T. droozi Muesebeck (Hymenoptera: Platygastridae), Winthemia occidentis Reinhard and Blondelia eufitchiae (Townsend) (Diptera: Tachinidae), as well as one species of Phobocampe Förster and Mesochorus vittator (Zetterstedt) (Hymenoptera: Ichneumonidae). None of them was a new Canadian record. To facilitate understanding of the regional parasitoid assemblage in Labrador, we compiled all published records in Canada and collated all specimen records from the Canadian National Collection of Insects, Arachnids, and Nematodes (Ottawa, Ontario, Canada). This comprehensive list will aid researchers interested in potential biological control candidates for hemlock looper.

On the evening of August 13th, 1881, I observed them between the hours of 5 and 7 o'clock. The air for miles around seemed literally alive with these dragon-flies, from a foot above ground to as far as the eye could reach, all flying in the same direction, a south-westerly course, and the few that would occasionally cross the track of the majority could all the more easily be noticed from the very regular and swift course they generally pursued; but even these few stray ones would soon fall in with the rest again. Very few were seen alighting, and all carefully avoided any movable obstacles.

The next day very few were seen on the prairies, and these mostly of another species very abundant in this country, Anax junius (Drury), which were probably at home previously, and in a few days I could see none others but the latter. A few newspapers, and also a few correspondents from twelve to fifteen miles east and west of here, had observed and mentioned their flight.

All the described species of Balaninus in habiting America north of mexico when larvæ live in the fruit (nuts and acorns) of the various species of Quercus, Castanea, Corylus, and perhaps Fagus of the order Cupuliferœ and Carya of the Juglandaceœ. Acorns, somewhat largely used in this country in the arts and in the manufcture of certain dietetics, are mostly imported, the native production being rendered almost worthless by these larvæ; and our chestnuts as soon as collected must be kiln-dried or otherwise treated, which renders them greatly inferior to those of foreign countries.

Drift of aquatic arthropods was not uniformly distributed by depth in a stream and differed from one reach to another. Drift of terrestrial arthropods, although usually densest at or near the surface, was also substantial at depths. Nets for sampling of drift should extend to the bottom and include the surface.