The two species described herein bring the total number of known species of New World Cyrtinini to 17. Since the descriptions are scattered and no key to these species Gas previously available, a brief key to the genera and species in the tribe is presented, being based in part on the descriptions only. I examined the species of Haldeman and Fisher, but not those described by Pascoe, Gahan, Hope, Bates, and Cameron. References to the original descriptions are given by Leng (1920, p. 281) and Blackwelder (1946, pp. 619, 620, and 1957). In Blackwelder's 1946 work the date given for the description of Sciocyrtinus Fisher on page 620 should read 1935 instead of 1934. I wish to thank Mr. W. S. Fisher, Washington, D.C., for checking the key and examining specimens of the new species.

The foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), and the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), are among the serious insect pests found in greenhouses. The efficacy of microbial control against these insects has been demonstrated and can be enhanced by the combination of different microbial agents. This study evaluated the efficacy of Bacillus pumilus Meyer and Gottheil PTB180 and Bacillus subtilis (Ehrenberg) Cohn PTB185, used alone and together, to control these two aphids both in the laboratory and in greenhouse on tomato, Solanum lycopersicum Linnaeus (Solanaceae), and cucumber, Cucumis sativus Linnaeus (Cucurbitaceae), plants. The results from the laboratory tests showed an increase in mortality induced by all biological treatments. In the greenhouse, all treatments induced mortality rates significantly higher than that of the control for A. solani. Similarly, all treatments performed better than the control against A. gossypii, significantly reducing its reproduction. Furthermore, we found no additive effects when mixing products nor negative interactions affecting survival for the bacteria investigated. These microorganisms therefore have potential for use in biological control.

The survival and persistence of Nosema locustae Canning in field soils and resident grasshopper populations in Saskatchewan were assessed in a 3-year study. Low levels of N. locustae spores persist in soils but not on vegetation from treated fields. Large numbers of spores were sometimes detected in soil depending on the extent of infection in the resident grasshopper populations. Indigenous soil microorganisms appear to prey upon N. locustae spores or utilize nutrients during spore decomposition. Nosema locustae infection in resident grasshoppers varied, depending on the viability of the spores applied, and its level was higher following repeated (3-year) applications. Low numbers of N. locustae spores persist in soil but large populations probably will not accumulate because of leaching and because of their interaction with soil microorganisms. Spores appeared to leach through soil as a function of water movement.

The genus Dalbulus (Homoptera: Cicadellidae) consists of 11 species, 10 of which can be found in México (Nault 1990). Some members in the genus, such as the corn leafhopper, Dalbulus maidis (DeLong and Wolcott), and the Mexican corn leafhopper, Dalbulus elimatus (Ball) are serious pests of maize due to their transmission of three corn stunting pathogens: corn stunt spiroplasma (CSS; Spiroplasma kunkelii Whitcomb et al.), maize bushy stunt mycoplasmalike organism (MBSM), and maize rayado fino virus (MRFV) (Nault 1990). Due to the widespread damage that these leafhopper-vectored pathogens cause in maize-growing regions in Latin America, a search for the leafhopper natural enemies was conducted in maize agroecosystems in central México.

Gillette (3) described this species as Chermes similis in 1907. His description was of winged females from galls but he mentioned that wingless females and their egg clusters were also present in some galls, although there was no way to make certain that they were of the same species. The galls were on blue spruce from Colorado, and winged adults from these settled on spruce in cages. Patch (4) reported this species in 1909, on Norway, white, red, and black spruces from Maine. She found that the winged females settled 'on all these spruces but preferred white spruce. Wingless females with egg clusters were present in the galls and she assumed they were Chermes similis Gillette. Annand (1) placed the species in the genus Pineus, along with all species having four abdominal spiracles. He referred to the previous writers, and gave a description of a wingless adult, “probably from a gall”, included with Gillette's type material. He tentatively called this form a fundatrix. He also described a wingless female and a ‘nymph’ which Patch had found associated with galls of P. similis, as Pineus sp.

The two-spotted spider mite, Tetranychus urticae Koch, is an arrhenotokous species (Helle and Bolland 1967). Mated females produce both male and female offspring; unmated females produce only sons. Although there is no “normal” sex ratio for spider mites, a ratio of one male to approximately three females is often found in many tetranychid species (Wrensch 1985). The exact mechanism of the female-biased sex ratio is not fully understood, but previous studies have demonstrated several factors affecting the sex ratio in spider mites. In this report, we analyze the effects of maternal density, age, and the interaction between these factors on female daily fecundity and offspring sex ratio in T. urticae.

The need to exploit new sources of energy has recently led France to encourage several research programs toward the cultivation of crops for biomass production to extract alcohol, glucides, and chips for burning. To produce large quantities of biomass rapidly, several species of Populus have been selectively tested in short rotation coppices on about 400 ha in several parts of the country.

Among the practical consequences of this policy, one appears to be harmful, namely the spatial extension of several pests, mainly leaf eaters or polyphagous insects. These insects previously were located in poplar nurseries. Among the leaf eaters, larvae and adults of the poplar leaf beetles Chrysomela (= Melasoma) populi L. and Chrysomela tremulae F. feed on many poplar species in central France (e.g. Populus tremula L., Populus trichocarpa Torrey and Gray, Populus deltoides Bartram, Populus lasiocarpa Oliver).

In this study, we assessed the relationship between the size of bolts cut from pin oak trees, Quercus palustris Münchhausen (Fagaceae), and eastern white pines, Pinus strobus Linnaeus (Pinaceae), and the number and body size of cerambycid beetles (Coleoptera: Cerambycidae) that develop within them. From oak bolts emerged adult Graphisurus fasciatus (De Geer) (98% of beetles) and Xylotrechus colonus (Fabricius), while pine bolts produced Monochamus carolinensis (Olivier) (95%) and Astylopsis sexguttata (Say). The number of G. fasciatus was positively correlated with the diameter of the oak bolts, while the greatest number of M. carolinensis emerged from pine bolts of intermediate diameter. Body size of both species was positively correlated with bolt diameter. Rates of parasitism were very low, only 0.9% for oaks, and averaging 5.3 ± 8.6% across pine bolts. Oak bolts yielded the braconid wasps (Hymenoptera: Braconidae) Wroughtonia ferruginea (Brues) and a species in the genus Atanycolus Förster (similar to Atanycoluscharus (Riley)), and an ichneumonid (Hymenoptera: Ichneumonidae) in the genus Demopheles Förster. Pine bolts produced a braconid in the genus Digonogastra Viereck, and the tachinid fly (Diptera: Tachinidae) Billaea monohammi (Townsend).

Since a technique for mass rearing of the cabbage maggot Hylemya brassicae (Bouché), was described (Read, 1960), inquiries from different countries indicate that many workers encounter difficulties in rearing this insect in captivity. This paper discusses these difficulties and describes methods successfully used by the authors for establishing and maintaining cultures in the greenhouse. Using these methods, 22 successive generations of H. brassicae have been reared at Belleville in less than four years.

Larvae of the eastern hemlock looper, Lambdina fiscellaria fiscellaria (Guen.), are susceptible to a nuclear polyhedrosis virus as well as nuclear polyhedrosis viruses isolated from the western hemlock looper, L. f. lugubrosa (Hulst), and the western oak looper, L. f. somniaria (Hulst). The pathogenicity of these viruses was similar when tested on eastern hemlock looper larvae and it is suggested that the same virus infects the three subspecies. Resistance to the virus did not increase with age; second-, third-, and fourth-instar larvae were equally susceptible. The period from ingestion to death varied with concentration of virus and rearing temperature. Results of pathogenicity tests are given.

Collection and rearing records for 1951 to 1954 indicate that a parthenogenetic and a bisexual form of Hypolithus bicolor Esch. occur in Saskatchewan.

Near White Fox, in the northeastern area of the Mixedwood Section, approximately 2,000 beetles were collected from their hibernation cells in the soil and from the soil surface, in fields of native sod, summer-fallow, and crop, at various times during the frost-free periods. All the beetles were female. Sixty beetles reared from larvae collected in this area were also females. Similarly, there were no males in a collection of approximately 300 beetles from near Meadow Lake, in the northwestern area of the Mixedwood Section, and in numerous smaller collections made in other parts of this section. Eleven beetles, all females, were reared from eggs laid by beetles of this parthenogenetic form collected near White Fox during the last week in May, 1952. After a storage period of four months at 38°F., seven of these first generation beetles laid viable eggs without mating. No attempt was made to rear the second generation larvae to the beetle stage.

Fecundity and colony size of Hyphantria cunea Drury were measured in six census areas for 13 years, and wing length was measured in one area. Colony size in the fifth instar was closely correlated with fecundity, and the percentage mortality from the egg stage to the fifth instar was an inverse function of fecundity. Wing length was not a sensitive index of fecundity where there was insufficient competition for food to cause severe reduction in moth size.Seasonal differences in fecundity and colony size within years, as well as differences between areas and between years, followed patterns expected from laboratory studies. Decreases during each season, proximately attributable to the age of foliage available to the larvae and ultimately attributable to genetic differences in the heat requirements for diapause termination, made it difficult to estimate mean fecundity for any area or year. Fecundity seemed slightly higher in coastal than in inland areas. Both population quality and weather appeared to influence annual differences, but because of the complex interaction between them and the high variability in fecundity and colony size, the relationships could not be modeled effectively with the available data.Differences in fecundity and colony size associated with both time and place were negligible in comparison to the changes in the population density of colonies, as measured in the same areas over the same period of years. It is concluded that priority should be given to survival rather than fecundity in the development of population models for H. cunea, at least in areas where competition for food is not severe.

Many entomological problems require the identification and observation of insects without disturbing their surroundings. Such problems are usually concerned with insects within host or pupal coverings and radiography is a method well suited to their solution. The technique is a special type of radiography in which soft X-rays (wave length longer than about 0.25A), passing through an object of low density, produce a shadow image on fine-grain film in contact with the object.

The two subgenera and 20 species of the crab spider genus Ebo in North America north of Mexico are described or redescribed, keyed, and illustrated. The subgenus Ebo contains seven species, of which E. iviei, E. evansae, E. contrasts, and E. punctatus are described as new and the female of E. merkeli Schick is described for the first time. The subgenus Titanebo contains 13 species, of which E. cantralli is described as new and the female of E. texanus is described for the first time.

The following Canadian records of fleas occurring north of the 60th parallel have resulted from a recent study by the writer of the Siphonaptera contained in the Canadian National Collection at Ottawa. Most of the material dealt with here was collected by C. H. D. Clarke of the Bureau of Northwest Territories and Yukon Affairs, or by various officers of the Royal Canadian Mounted Police during the survey of the Thelon Game Sanctuary.

In the laboratory, endosulfan and phosalone were non-toxic to adult Pterostichus melanarius and Harpalus affinis and of relatively low toxicity to Amara spp. Phosmet was non-toxic to P. melanarius but was toxic to Amara spp. and to a lesser extent to H. affinis. Azinphos-methyl, permethrin, and dimethoate were considerably more toxic to the latter two species than to P. melanarius. Diazinon was toxic to all species and methyl and ethyl parathion were highly toxic to P. melanarius. Bembidion quadrimaculatum was susceptible to most insecticides except endosulfan and phosalone. Mortality in the field generally supported laboratory findings. Diazinon caused the greatest mortality to all species and permethrin caused some mortality to all species. Phosmet was highly toxic to H. affinis and Amara spp. Generally the toxic effects of the insecticides were of relatively short duration.

A new genus, Dianemobius, is diagnosed, with Eneoptera fascipes Walker, 1869, as type-species, since this species is not congeneric with Pteronemobius concolor (Walker), the type-species (a senior synonym of the originally designated Nemobius tartarus Saussure) of Pteronemobius. Notes on morphology and cytology which indicate the heterogeneity of Pteronemobius are included.

Since 1947, when the bramble leafhopper, Ribautiana tenerrima (H.-S.) (rubi Hardy, misella 13011.), was first reported in North America near Victoria, B.C.,it has become a serious pest in cane fruit plantings on southern Vancouver Island and the lower Fraser Valley. Hoth nymphs and adults suck the sap from the leaves, producing a white stippling on the upper surfaces (Fig. 1). In a dry season a severe infestation causes many leaves to become curled and appearburned. The canes lack vigor and the size of the fruit is reduced. This is a report on a study of the life history and behavior of the species conducted at Victoria from 1953 to 1957.