The percentage encapsulation of its common insect parasites by Hyphantria cunea Drury was measured in natural populations in New Brunswick and Nova Scotia over a period of 17 years, and the variables affecting encapsulation were studied in laboratory experiments. Percentage encapsulation varied with the species, stage, and activity of the parasite, and the stage and genetic strain of the host. Differences in encapsulation from area to area and particularly from year to year were closely related to short-term changes in the genetic constitution of the host population resulting from natural selection pressures. The application of these results to biological control and to population modeling is discussed briefly.

Mexican bean beetles, Epilachna varivestis Mulsant, were marked with rubidium by allowing larvae and adults to feed on foliage of bean plants treated with a rubidium chloride solution. Detection of rubidium was effected by atomic absorption spectroscopy. Adults which had fed for 4 days on rubidium-chloride-treated plants then transferred to untreated plants contained elevated levels of rubidium up to 34 days. The presence of rubidium was not detectable in the progeny of treated beetles at levels significantly different from controls. Consumption of rubidium-chloride-treated foliage produced no observable detrimental effects on the beetles. The technique allowed them to acquire a relatively permanent label through their normal feeding activity.

All species of the subgenus Microsaurus Steph. of the genus Quedius Steph. (Staphylinidae), known to occur at present in Mexico, are treated. A key is given. Three species are described as new.

Antifeedants for controlling larval feeding of several Neodiprion sawflies were evaluated in laboratory and field studies. Nine commercially available insect antifeedants and a hexane extract of the juvenile foliage of jack pine, Pinus banksiana Lambert, were tested on larvae of six species. In laboratory bioassays larvae exhibited varying sensitivity to antifeedants; generally species with monophagous or restricted oligophagous feeding habits were most sensitive. In the laboratory the Swaine jack pine sawfly, Neodiprion swainei Middleton, had severely restricted feeding, development, survival, and fecundity. Triphenyltin hydroxide was toxic to N. swainei and to European pine sawfly, N. sertifer (Geoffroy). In field tests certain antifeedants disrupted N. swainei feeding and development. The colonial behavior of larvae often was disrupted and solitary larvae fell from trees or wandered on twigs. Colony disruption by most antifeedants was temporary and many larvae resumed feeding.

Examination of the salivary glands and the saliva of the six-spotted leafhopper, Macrosteles fascifrons (Stål), with the transmission electron microscope revealed three kinds of membrane-limited bodies. Typical mycoplasma-like bodies (MLBs) were found in the salivary glands of leafhoppers transmitting aster yellows, but were absent in those never exposed to a disease source. Rickettsia-like bodies (RLBs) and other small bodies named salivary bodies (SBs), apparently associated with the secretion of saliva, were found in both transmitting and nontransmitting leafhoppers. Pronase digested the SBs in 20 min and pepsin in 2 h, but neither enzyme had any effect on MLBs or RLBs.

Forty-six species of adult Miridae were recorded from Solidago canadensis L. in south-eastern Ontario. Major resident (breeding) species were determined on the basis of the relative abundance of nymphal and adult populations recorded from six plot-years. Although the composition of the mirid fauna varies temporally, over 90% of the Miridae belong to the following group of seven species: Slaterocoris breviatus (Kngt.), S. atritibialis (Kngt.), Lygus lineolaris (Beauv.), L. vanduzeei Kngt., Plagiognathus cuneatus Kngt., P. politus Uhl., and Polymerus venaticus (Uhl.).

Total nymphal abundance is seasonally bimodal, relating to species differences in overwintering stage. The Lygus species overwinter as adults, and nymphs are abundant primarily in August, The remaining five species overwinter as eggs and their nymphs are present primarily during May to mid-July. In contrast to the bimodal phenology exhibited by nymphs, adults are temporally grouped in the mid- to late season, with adults of both overwintering classes overlapping. The adults, however, follow a characteristic sequence of initial occurrence, from early to late season, of: S. atritibialis, P. venaticus, L. vanduzeei, S. breviatus, P. politus, P. cuneatus, and L. lineolaris.

In tests conducted on the Kenai National Moose Range, Alaska, seudenol and α-pinene attracted more spruce beetles (Dendroctonus rufipennis (Kirby)) than did frontalin and α-pinene, the best previously reported synthetic attractant. Addition of methylcyclohexenone (MCH) to sticky traps baited with spruce logs (Picea glauca (Moench) Voss.) infested with 20 female spruce beetles or to traps treated with seudenol and α-pinene reduced the number of spruce beetles caught by 87% and 99%, respectively. MCH appears to have similar repressive effect on the attraction of spruce beetle populations that differ in their geographic locations and hosts. A total of 179 other scolytids, representing 8 genera and 10 species, were caught by traps; greatest numbers were attracted to treatments containing trans-verbenol and uninfested spruce log sections. Scierus pubescens (Swaine) was recorded from Alaska for the first time. No members of Thanasimus species were caught although they have been consistently present in abundance in similar tests elsewhere.

Spruce budworm infested balsam fir trees were aerially sprayed with Bacillus thuringiensis – chitinase combinations at the rate of 4 Billion International Units of B.t. and 18 mg of enzyme in 0.5 gal/acre. Larvae were peak third instar at spray time. Deposit rates ranged from 1.07 to 3.26 BIU/acre. Efficacy of the treatments was assessed in the year of treatment and carry-over effects were assessed 1 year later.

Results in the year of treatment indicated that: (1) Residual activity of B. thuringiensis was drastically reduced after 15 days’ exposure to weathering. (2) Larval mortality alone is not a suitable criterion of efficacy. (3) Dipel and Dipel + chitinase (but not Thuricide 16B or Thuricide + chitinase) were highly effective in reducing budworm densities. (4) Thuricide + chitinase treatment resulted in significant foliage protection. The treatments inhibited feeding in the following order of efficiency: Thuricide + chitinase > Dipel + chitinase > Dipel alone > chitinase alone > Thuricide alone. (5) There was no direct relationship between larval mortality and foliage protection in any of the treatments, likely due to delayed mortality effects. (6) No direct relationship exists between viable spore deposits and deposit of active ingredient (IUs). (7) B.t. treatments retarded development of the spruce budworm and reduced pupal weights, oviposition rates, and egg viability.

Assessment of the plots 1 year after spray showed that the treatments apparently gave no long term protection from defoliation, but this was likely due in part to mass invasion of the test plots by moths from immediately surrounding untreated areas.

A terminology useful in describing conocephaline amplitude modulation patterns is presented in this first part of a three-part study of calling songs in Orchelimum meadow katydids. Geographical distributions are mapped for the 18 species which occur in North America north of Mexico and several substantial range extensions reported, Comparison of stridulatory files indicates two types within the genus, one characterized by more widely spaced teeth near the basal end of the file. Teeth are asymmetrical in accordance with the generation of the loudest song components on wing closure.

The nesting behaviour of the euglossine bee Euplusia surinamensis was observed on the Osa Peninsula of Costa Rica. We found that female bees nest in aggregations, re-use old nests, will take over abandoned nests shortly after the original owner is removed, and will fight off invading bees which attempt to take over their nests. We suggest that the nesting aggregations give bees the opportunity to use old nests and take over partially provisioned nests if the original owner disappears. In this way bees are able to increase their rate of egg laying above that which would be possible with solitary nesting and de novo nest construction.

The relationship of pheromone trap catch to emergence and oviposition of the codling moth was defined for the two-generation climate of Michigan. Catch anticipated emergence and oviposition during spring flight when the trap displayed greatest efficiency, but lagged behind emergence and closely followed oviposition during the second generation. Trapping efficiency declined towards the end of the first generation and was generally lower during summer flight. Factors which possibly relate to this efficiency loss are discussed. First catch and the catch peaks in both generations were evaluated as reference points for the prediction of phenological events (particularly egg hatch) in both generations Of four forecasting methods, degree day and developmental unit summations, starting from first catch, for the preoviposition and incubation period were most reliable in predicting the beginning of spring brood egg hatch.

Life table data from a laboratory strain of Tribolium confusum (DuVal) were obtained for use in deterministic and stochastic models of population growth under optimal environmental conditions. Frequency distributions of mortality, developmental time, and age-specific fecundity schedules taken from experiments conducted at five constant temperatures were transposed onto a physiological time scale measured in degree-days. Data of this detail were necessary for use in models that could predict the growth of laboratory populations of the same strain of beetle reared under optimal conditions.

As part of the biological control of Canada thistle, Cirsium arvense (L.) Scop., in Canada, a survey of the insect fauna showed 80 identified or apparent phytophagous species representing 24 families and seven orders and 47 species of visitors, insect parasites, and predators representing 28 families and six orders. Thirty-eight per cent of the phytophagous insects attack economic plants. Three species, Altica carduorum, Ceutorhynchus litura, and Urophora cardui, are specific to C. arvense and were introduced as control agents.

The within-sample distributions of gallery length (GL) and egg (E) density as well as their functional relationships to the infested bole were studied in an epidemic population of the southern pine beetle in southeast Texas.

A least-squares linear regression analysis through the origin showed an average of 1.59 eggs per centimeter of gallery. GL accounted for 81% of the variation in E and thus is useful for estimating egg numbers. The density of attacking adults is unsatisfactory for predicting E.

GL and E are uniformly distributed within but not among the 100-cm2 sample disks at a given height. The functional relationship of both variables to the infested bole is adequately described by the model y = (A+Bx)exp(Cln(x−x2)), where y = GL or E per 100 cm2, x = the normalized height on the infested bole, and A, B, and C are parameters to be estimated for each set of data.

Bionomics of the stream caddisflies, Ceraclea transversa (Hagen) (= Athripsodes angustus Banks) and Ceraclea ancylus (Vorhies) (= Athripsodes ancylus (Vorhies)) were compared with generalized trichopteran life cycles. The univoltine detritus-feeding C. ancylus has five larval instars and a brief adult emergence period. C. transversa has five larval instars but two distinct cohorts, in which larvae of the first cohort feed entirely on freshwater sponge, overwinter as inactive prepupae, pupate, and emerge the following spring. The second larval cohort feeds on sponge until the onset of gemmulation in autumn, then the larvae must overwinter as active third- or fourth-instar detritus-feeders, pupating and emerging later in the summer than the first cohort. The detritus-feeding C. ancylus larvae have a diurnal feeding cycle. The sand case of C. ancylus and the silk-secreted case of C. transversa differ in shape and composition, although both species initiate case construction using egg mass matrix, silk, and detritus. Emergence, flight activity, sex ratios, and adult survival depart from reported generalizations of caddisfly biology. Neither the validity of generalizing typical life cycles in benthic studies, nor the rationale that congeneric species operate as a functional unit in stream dynamics, is substantiated.

The broad-necked root borer, Prionus laticollis (Drury), causes economic damage to apple orchards in the eastern United States by boring in the roots of apple trees. The insect has a 3- to 4-year life cycle. Eggs are deposited in the soil or on the soil surface in mid-summer, and larvae tunnel through the bark and may excavate the interior wood of living, weakened, or dead apple tree roots. Larvae leave the roots to pupate in the soil and have been found up to a depth of 84 cm below the soil surface. Prepupae occur in the soil during May and June and pupae in June and July. Adults live approximately 1 week after emergence and mate several times. A tachinid fly, several potential pathogenic microorganisms, larvae biting one another, and freezing temperatures were observed to be mortality factors.

Brachypogon canadensis n. sp. is described from western Quebec; the known range of the species extends southwards to Florida. It is perhaps most nearly allied to the widespread Palaearctic species B. vitiosus (Winnertz).

The concept of degree-day summation was employed in three models of malthusian growth predictive over a range of temperatures. When supplied input data from life table studies conducted at five constant temperatures, the models were able to predict the magnitude and pattern of growth of populations of Tribolium confusum Duval reared under malthusian conditions. The stochastic model, moreover, revealed that the series of chance events found in the course of population growth could explain differences between one population and the next. When computer experiments on the importance of various life table parameters were run, the models revealed the overwhelming importance of time taken to mature on the rate of population growth. The level of fecundity was next in order of importance while population growth was least sensitive to changes in survivorship.

A new genus and species of Phoridae, Zyziphora hirtifrons, is described from Colorado.

In Hylemya brassicae (Bouché) little oviposition occurred when access to host plant material was denied. The mustard oil, allyl isothiocyanate (AITC), stimulated the flies into greater activity and attracted them to its source. Sinigrin and four other glucosinolates (mustard oil glucosides) tested induced oviposition. AITC by itself did not induce, oviposition, but in the presence of a glucosinolate, small concentrations of AITC caused an increase in the number of eggs laid. Glucose, sucrose, casein, wheat germ oil, and a mixture of B-vitamins did not influence oviposition at the concentrations tested, but casein hydrolysate inhibited it. The role of glucosinolates and common nutrients in host selection by H. brassicae is discussed.