It is not unusual for parasite attack on insect hosts to have different consequences for individuals of the same species. An indication of the variation in types of alternative effects is given by a consideration of three host-parasite relationships. First, although most hosts in a population are susceptible to parasitization, some are immune to attack: about one in 3,000 larvae of the Mediterranean flour moth, Anagasta kühniella (Zeller), was found by Payne (1934) to be immune to attack by Bracon hebetor Say. Second, tile morphology of hosts may be modified differentially by parasitism: unhatched eggs of Aphdius platensis Brethes exert a juvenilizing effect on nymphs of Aphis craccivora Koch whereas parasite larvae sometimes cause the appearance of adult characters (Johnson, 1959). Third, some hosts are successfully parasitized whereas others are killed long before parasite progeny can mature: adult females of Metaphycus helvolus (Com.) kill the black scale, Saissetin oleae (Bern.), by parasitization, by mutilation with the ovipositor, and by host-feeding at wounds made by the ovipositor. Field tests showed that up to 97 per cent of a black-scale infestation may be killed by the parasite over a period of several months.

Sevin (1-naphthyl N-methylcarbamate) was first shown to have miticidal properties in 1957 when Allen et al. (1) found that it was moderately effective for the control oi the cyclamen mite, Steneotarsonmus pallidus (Banks), on strawberries. Subsequently it was demonstrated that Sevin would control the northern fowl mite, Ornithonyssus sylviarum (C. and F.) (7, 8, 9), suppress the brown mite, Bryobia arborea M. and A. (18), and the peach silver mite, Vasates cornutus (Banks) (18), and practically eliminate the predacious mite, Typhlodromus rhenanus Oudms. (18). It is not toxic to the European red mite, Panonychus ulmi (Koch) (18), the desert spider mite, Tetranychus desertorum Banks (4), and the two-spotted spider mite, Tetranychus telarius (L.) (6, 15); usually the use of Sevin for insect control will increase the numbers of these mites, and in this respect its effect is similar to that of DDT.

In recent years, Bacillus thuringiensis (Berliner) and other entomogenous spore-formers have received increased interest in view of their great potential for insect control. These insect pathogens are generally known as “microbial insecticides” and are so-called because of a spore-associated protein crystalline inclusion which have been shown to be toxic for some insects (Angus 1956). Krieg (1961) lists some one hundred insects, mainly Lepidoptera, which are susceptible to Bacillus thuringiensis and closely related bacteria.

The European pine shoot moth (Rhyacionia buoliana (Schiff.)) attacks pine species grown in Michigan for forestry, Christmas tree, and ornamental purposes. Much research has been carried out on life history and direct insecticide control, (Butcher and Haynes 1960; Donley 1960) in efforts to minimize injury. As a result of these studies, practical control methods have been developed for intensively managed stands such as Christmas trees and nursery stock. While the need for a better understanding of shoot moth biology and ecology is generally accepted, the inability of foresters and entomologists to obtain satisfactory shoot moth control with low gallonage insecticide applications under forestry conditions has given impetus to studies on host preference and the influence of the host on shoot moth success and development. Such information, when available, might conceivably suggest planting and management steps that foresters could take in order to minimize attack and injury by this pest in the future. In Michigan, the European pine shoot moth overwinters as a partially grown larva and feeding is resumed about April 20. By late May or early June, pupation takes place in the bud area and adults emerge in about 2 weeks. Eggs are laid on the bark and needles, and hatching occurs within 10 to 15 days. Newly hatched larvae feed at the base of the current year's needles, later moving to the terminal and lateral buds where they remain until the following spring. Pitch blisters or “tents” formed as a result of feeding. in the bud area are useful indicators of shoot moth presence and activity.

Many insects ingest food through needlelike mouthparts adapted for piercing. The piercing organ itself usuallv consists of four or more chitinous stylets and is thought to be nonliving. It was therefore unexpected to find that amputating the end of a single stylet had two marked effects on aphids; it prevented feeding, and adults produced far more young than usual while starving (Bradley, 1960). Later I found that these effects can also be caused by inserting the intact stylet tips briefly into various solutions such as nitric acid, formalin, or procaine. An account of this work and of that which followed on how solutions initiated these effects is the scope of this paper.

The effects of exposure to sub-freezing temperatures on the survival of insects have been studied experimentally mainly in three types of insect. One is the beetles associated with stored products, including Bruchus obtectus (Carter, 1925), and Tribolium confusum (Nagel and Shepard, 1934, and Salt, 1936). A leaf feeding beetle, Popillia japonica (Payne, 1928) has also been studied. The emphasis of these studies has been on the possibility of physical control of these pests. The second type includes the hitch-hikers on aircraft. Knippling and Sullivan (1957) studied the survival of six species of insects and a tick which were exposured to 0, −5, −10, −15, −20, and −30°C. for one hour, and that of one of the insects, the house fly, to −20° for different durations up to 60 minutes. Their objective was to determine the possibility of these arthropods being transported alive by aircraft. Thus, the conditions which they tested were those which may be encountered by the arthropods in the unheated parts of jet aircraft during flights in the stratosphere. The third type of insects is Drosophila, mainly D. melanogaster. Since the present paper deals also with this insect, pertinent facts reported by earlier authors are summarized in Table I.

Pending completion of the writer's current bumblebee work, the following information should be of interest and use to others who are now devoting attention to the taxonomy of this group in the Western Hemisphere and who contemplate publishing. The existing and recognizable types of all the accepted names referred to beyond were studied except the Gribodo types which were well reviewed by Richards (1929), inrhose homotype of volucelloides was examined at the British Museum (N.H.) in London. The condition and where-abouts of most of the type specimens on which are based the various conclusions presented here, have already been discussed by the writer (1960). There are, however, other types of infraspecific taxa that were not treated at that time, and it is emphasized that a reliable knowledge of these is also important for the present synonymies and other taxonomic considerations.

Any continuous or undivided sclerotized plate of the exoskeleton is known as a sclerite and when two sclerites are contiguous the line of junction or demarcation is commonly known as a suture. Sutures in this accepted sense are of three kinds. The most common is a depressed line at the bottom of a shallow furrow or sulcus which marks the position of an internal strengthening ridge. The ridge may be formed in tnro ways.

Some bark beetle parasites insert their ovipositors through the bark of trees to lay their eggs on their hosts. To be parasitized, therefore, host insects must be beneath a thickness of bark less than the parasite ovipositor length. Bark thickness varies at different heights in a tree, but even at a given height the thickness is not uniform because of the fissures. The percentage of bark beetles parasitized by this type of parasite at a given height in a tree is influenced by the percentage of the bark which has a thickness less than the parasite ovipositor length.

Local outbreaks of Lecanium coryli L. on white elm, Ulmus americana L., at Indian Head and Regina, Saskatchewan, were investigated from 1957 to 1960. Information on the seasonal occurrence, habits of the females, natural mortality, and chemical control of the scale has been reported (Peterson, 1960). During this investigation, data on insects attacking the scale were collected and are presented in this paper. Eleven species of hymenopterous parasites and one dipterous predator were collected. All were associated with the late nymphal stage and/or the adult stage of the female host. Table I lists the hymenopterous species and shows the numbers of adults and their emergence periods, recorded from 1958 to 1960.

Near Grand Manan Island, in the Ray of Fundy and about 20 miles from the coast of Maine and 30 miles from Nova Scotia, lie Kent Island and Hay Island. During the summer of 1961, we secured collections of bird nests from these islands so as to study the flea fauna. Nests of the following species were collected: Larus argentatus, herring gull; Somateria mollissima, common eider; Corvus brachyrhynchos, crow; Oceanodroma leucorhoa, Leach's petrel; Riparia r. riparia, bank swallow; Hirundo rustica erythrogaster, barn swallow; Petrochelidon pyrrhonota albifrons, cliff swallow; Iridoprocne bicolor, tree swallow; and Passerculus sondwichensis, savannah sparrow. The nests of herring gulls, eiders, crows, and Leach's petrels proved to be without fleas, but from the other nests 797 fleas were collected.

Senecio longilobus Benth. (thread-leaf groundsel) is considered to be one of the most poisonous of the groundsels, especially to cattle and horses, although it has been used extensively in the domestic medicine of the Indians (Kearney and Peebles, 1951). Apparently the leaves of new growth are most toxic and the primary effect is to produce lesions in the liver. Other species in the genus are less poisonous but are capable of developing cumulative effects when ingested by livestock in small doses over extended periods of time. The alkaloids present in several of the toxic species have been isolated, but not all of the Senecio species contain alkaloids, nor are all of the alkaloids toxic to livestock. Manske (1931) has reviewed some of the literature on the subject and proposed the generic name necine for the basic hydrolytic product and necic acid for the acid fragment.

Natural control factors are normally relied on to hold destructive insects below the level of economic damage. When insect control is attempted every effort should be made to prevent injury to beneficial parasites and predators.

The Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, is an important enemy of Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco. Present control practices for the Douglas-fir beetle consist of rapid cutting, transportation, and milling of infested trees so that beetles will be destroyed in the slabs before they emerge to infest other trees. During these operations, natural control agents are often inadvertently destroyed along with the beetles. Because of this fact serious beetle infestations may be unnecessarily prolonged. Detailed knowledge of the life history of the narural control agents and of the effect of logging and milling practices on the populations of beneficial parasites and predators is needed before control practice recommendations, which may be less destructive to the beneficial insects, can be set forth.

During the course of work towards a revision of rhe genera of the Rhyparo-chrominae of the world, a number of systematic changes have been found necessary. These are published now so that they may be used in forthcoming publications and so that they may be incorporated in a world catalogue of the Lygaeidae now in preparation by J. A. Slater. This is the first of a series of papers on the subfamily Rhyparochrominae, which will be published prior to the appearance of the final keys to all the genera.

Four colonies of Chrysolina quadrigemina (Suffr.) and two of C. hyperici (Forst.) were released in 1951 and 1952 in the souvhern interior of British Columbia (Fig. 1) in the hope of duplicating the successful biological control of Hypericum perforatum L. in California. In 1956, Smith (1958) showed that though the colonies were still present, the weed had increased in all areas. By 1960, however, C. hyperici had greatly reduced the abundance of H. perforatum at Fruitvale (Fig. 2) while at Edgewood the beetle had disappeared. A colony of C. padrigmina at Edgewood had also disappeared and the three other C. quadrigemina colonies persisted at a low density without controlling the weed. For example, at Christina Lake (Fig. 3) a few beetles were found every year since release, though they had not always appeared in the sample plots. The annual fluctuations of the weed as indicated in the figure were probably of climatic origin as they were similar to those for the other areas. The most promising of the C. quadrigemina colonies was at Fife where, though there were few beetles in the release meadow itself, they were common on the slope below.

The species described herein is referable to the subgenus Hyperomyzus Börner, which includes the species of Nasonovia in which the cornicles are swollen. This species can be distinguished from the two orher species known to occur in North America by means of the following key:

1. Apical segment of hind tarsus longer than apical rostral segment; antennae with apical portions of segments usually darker in macerated material; broadest portion of cornicles usually not much wider than broadest portion of cauda ___2