Longevity and fecundity data are presented for cohorts of cabbage aphid, Brevicoryne brassicae (L.), reared on different hosts (Barbarea vulgaris, Brassica pekinensis, and two varieties of Brassica oleracea) and under constant and fluctuating environmental conditions. Changes in fecundity and development were the chief causes for the different rates of population increase (r) observed on each host. Alate forms developed only in the cohort reared on B. vulgaris, the most resistant host studied. Host factors, acting during the late prenatal period or during postnatal development, appear to be capable of influencing form determination in this aphid.

Acanthoscelides mucrofer new species is described from Texas and A. helianthemum new species from Florida and Georgia. These are compared with A. tenuis Bottimer and A. atomus (Fall), respectively. Photographs of the four species are included. A. helianthemum had been previously reported from Florida under the name Bruchus compressicornis Schaeffer. The host plant of A. mucrofer is unknown. The following rearing records are reported: A. tenuis from Lythrum alatum and L. lineare; A. helianthemum from Helianthemum corymbosum; A. atomus from Lechea tenuifolia and L. racemulosa; and A. compressicornis from Desmanthus virgatus.

Most Empididae are predators on living insects, but a few instances of other feeding habits have been discovered. It is shown that Anthalia bulbosa (Ocydromiinae) eats the pollen of several flowers, and other possible cases of pollen-eating in Ocydromiinae and Empidinae are discussed. Micropborus obscurus (Empidinae) feeds on dead insects trapped in spiders’ webs, in agreement with Laurence’s finding for M. crassipes; and several reports of Clinoceratinae feeding on dead insects at the water’s edge are assembled. This diversity of feeding habit finds a parallel in Ceratopogonidae.In Empididae the protein-rich meal, whether of insect prey, dead insects, or dead pollen, is taken in typical cases by both males and females, as would be expected on systematic grounds. The sexual differentiation of hunting and feeding habits (males hunting, perhaps not feeding; females non-hunting, receiving prey by transfer at mating) is a specialized feature restricted to the Empis–Hilara–Rhamphomyia group (Empidinae).

The lateralis medius, an indirect flight muscle of Black Hills beetles, degenerated abruptly in females within 3 days after attack. Egg laying began at the end of the 3 days. Thickness of the muscle changed much more than width. Regeneration began in most ovipositing females about 10 days after attack. Steady development of the muscle to its maximum size, reached prior to beetle emergence, offers a method of forecasting emergence.

Final instar larvae of fall webworms, Hyphantria cunea (Drury), were labelled to equilibrium levels on persimmon leaves containing 45Ca. Loss rates of 45Ca from the larvae were followed in the laboratory after either feeding larvae on unlabelled leaves, or starving other larvae.Initial loss-rate characteristics were different in the two feeding treatments, but biological half-lives were not significantly changed. Feeding shifts the time at which the lower loss-rate comes into effect.

Feeding activity is a crucial measure used in experiments with larvae of Pseudosarcophaga affinis auct. nec Fallén on chemically defined diets to determine whether food selection and preference occurs because of nutritional factors. To avoid temporal bias in recording it was necessary to know: (1) when during larval development feeding activity is greatest; and (2) whether a diel periodicity of feeding activity demands that observations be standardized according to time of day. Experiments done at 23 °C and 16-hour photoperiod with new-born larvae showed that: (1) during larval life feeding activity increases rapidly up to 96 hours of age and thereafter slowly decreases; and (2) on the two diets tested more feeding occurred during darkness but only on one diet was the difference (about 7.3%) statistically significant. Thus in P. affinis it is seldom necessary to control for time of day in experiments of the kind used in the work on food selection and preference.

The genus Melocosa Gertsch, 1937, is transferred from Pisauridae to Lycosinae in the Lycosidae. The genus Melocosa is defined, and its characteristics indicate relationship to the genus Tarentula. Male and female specimens of the type species are described in detail and drawings of diagnostic characteristics are given. A key to the Nearctic genera of Lycosidae is given.

Both laboratory-reared and field-collected pupae of the pine butterfly, Neophasia menapia F. and F., exhibited varying degrees of dark pigmentation. Most of the pupae, however, lacked this characteristic. Pupal coloration was not due to sexual differences, parasitism, or the quantity of food available during development. Although light was necessary for pigment formation, the effect was nullified by providing light-green foliage or a white background for the larva on which to pupate. Dark-green foliage of the previous growth year had an intermediate effect. Larvae that pupated on twigs or against a black background developed heavy pigmentation.

Lamyctes sp. (Chilopoda) is a predator of Scutigerella immaculata Newport and rapidly decimates symphylan soil storage cultures. In a limited soil environment this centipede controls symphylan populations to a level allowing for normal plant growth. Field populations of this predator are too small to effectively control symphylan injury to seeds and transplants.

The San Jose scale, Aspidiotus perniciosus Comstock, is predominantly a bark-inhabiting species and develops most successfully on limbs in the top of the tree. Incrustations of scales often form on the bark, sometimes on the fruit, and never on the leaves. Numbers of 150 per cm2 are common on the bark, but they rarely exceed 10 on the fruit or 13 on the leaves. Mortality rate on apple trees is greatest on the leaves, somewhat less on the bark, and least on the fruit. Females occur most frequently on the bark and males most often on the leaves. The very few females that develop on leaves seldom reproduce.The distribution of the San Jose scale is quite variable throughout a tree but is more uniform on specific limbs and old twigs. Distribution on twigs less than 1 year old is never uniform; the basal half of these young twigs is always more heavily colonized than the distal half. Few males develop on young twigs and mortality of all scales is greater on this bark than on limbs and old twigs. The San Jose scale has a greater and more variable mortality on the young twig mainly because this wood is more readily injured by feeding of the scale and low winter temperatures. Thus, twigs up to 1 year old are good sample units only in light infestations and following mild winters. The older twig is the most reliable sample for biological surveys or for assessing insecticide treatments but it is more difficult to examine because it usually contains dead scales of many generations.

Laboratory population experiments and theoretical calculations are presented that demonstrate effective population suppression by the introduction of partially sterile cabbage loopers into a native population. The use of partially sterile males is advantageous because they are highly competitive with native moths, and since their progeny are sterile provides for population suppression over at least three generations. It is projected, based on experimental results, that 92% control can be obtained for three generations through a single release of partially sterile males. This modification of the sterile-male technique for Lepidoptera could result in control and sizeable savings in cost. Insecticide and other forms of control can be used simultaneously without any effect on the efficiency of the release program.

The serological relationships of Pissodes strobi (Peck) and P. approximatus Hopkins were examined using turbidimetric and immunodiffusion analyses. Hylobius pales Hbst. was used for heterologous comparisons. When turbidimetric analyses were performed using anti-strobi sera, heterologous reactions with P. approximatus were stronger than homologous reactions. Moreover, immunodiffusion tests substantiated this. These results appear to have broken a cardinal rule of serology: that hererologous reactions do not exceed homologous reactions in magnitude.These results could he due to a simple quantitative variation in the antigen extracts or to possible cross-reactivity between antigenically similar proteins. Another possibility is that the two populations are not separate species. Evidence obtained in this study seems to be in accord with cytological evidence obtained hi previous studies and does not support the designation of P. approximatus as a valid species.

A discriminant function is derived which effectively distinguishes Pterostichus pensylvanicus Lec. from P. adstrictus Eschz. The function is Z = −0.0861X + 0.1657Y, where X = total length of the pronotum at the midline, and Y = distance from widest part of the pronotum to its base. If Z is equal to or less than a critical value, Z0 = 0.0607, the specimen is identified as pensylvanicus; if Z is greater than Z0, it is adstrictus. The rate of error of the function for 182 specimens tested was 2%.

Fourteen insecticides were tested by direct contact against second-instar nymphs of a grasshopper, Melanoplus sanguinipes F. Of these, seven were judged to be sufficiently promising to be compared for toxicity and persistence as deposits on wheat seedlings. Comparison with a dieldrin standard showed that Dursban, Dibrom, and malathion were extremely effective by contact but had little persistence on growing wheat. Baygon was extremely effective by contact and showed some persistence. CIBA 9643 and dimethoate were the only two compounds to show persistent effects almost equivalent to dieldrin, and CIBA 9643 was more toxic than dieldrin by direct contact.It was concluded that CIBA 9643 was the only compound, of those tested, which might give grasshopper control equivalent to, or better than, dieldrin or the currently recommended dimethoate.

A new genus, Sharliphora, with type-species Tenthredo ambiguus Fallén is described. Key to genera of Nematini related to Sharliphora is presented.

Astehelius crypticus, a new genus and species of Orthoptera from Sonora, Mexico, is described. This taxon closely resembles the oedipodine genus Heliastus but is shown to belong to a different subfamily, the Gomphocerinae.

Feeding tests with adult Exeristes comstockii (Cresson) showed that each of the 10 amino acids commonly recognized to be "essential" is required for egg production. Fecundity on a diet where only these 10 constituted the amino acid component equalled that on the control diet which contained 19 amino acids. Fecundity was reduced by 80% on diets in which Na+ was substituted for K+ and by one-third when K was the only mineral added. Omission of Mn2+ or Ca2+ from, or addition of Zn2+ to, the control salt mixture (Wesson’s) did not affect fecundity. Females fed the control (chemically defined) diet or its 10% dilution (sucrose content maintained) for 30 days in the absence of host larvae laid more eggs initially when hosts were supplied than did females fed 1% control diet, honeydew, or 10% sucrose for a similar period. Thus, for E. comstockii, only food with a relatively high quantity and quality of amino nitrogen fed during absence of host larvae will significantly increase initial fecundity when such hosts are later encountered. This knowledge affects treatment of parasites when being held before release in biological control programmes.

An account is given of some malformations affecting the meso- and meta-thoracic legs of Diprion similis Htg. after larvae were reared at certain photoperiods.

A key is given for seven species of Aphis L. that occur on Cornus species in North America: caliginosa Hottes and Frison, corniella (Hille Ris Lambers), cornifoliae Fitch, helianthi Monell, maculatae Oestlund, neogillettei Palmer, and a new species that is described, nigratibialis Robinson. Host transfer attempts with helianthi and corniella are discussed.