Onymacris rugatipennis is one of several diurnal adesmiine tenebrionid beetles living in various habitats near Gobabeb in the Namib Desert, South West Africa.

Late in the active part of the female daily cycle and before they dig into the ground, females are often persistently followed by one or more males. Intruding male challenges to followers are commonplace. Following occurs during the latter phase of the morning and especially during the afternoon activity cycle. Early in these activity cycles the principle male activity is feeding. Males emerge in the morning earlier than females, and late in their activity period most males are engaged in following or attempts to dislodge other followers. Of the five diurnal adesmiine species living near Gobabeb, only the males of O. rugatipennis fight with one another and defend space. Their space is maintained above the site where a female has dug into the ground at midday or in the evening. Defense involves exclusion of other males from the immediate vicinity of the female. Alien males are immediately evicted, but on some occasions there are serious challenges. Pairs of males may engage in vigorous wrestling matches involving head butting, shoving, throwing, biting, and kicking. Evenly matched individuals may wrestle for over 30 min and for more than 20 falls. The winner of such encounters remains over the buried female. The last individual to hold the space in the evening may mate with the resident female. The observed behavior is not territorial in the sense that there are no mutually recognized frontiers. There is, however, exclusive use of space and aggressive defense of that space.

Social order is re-established daily. There are no persistent inter-individual bonds between males and females. Males may return to the general area but not the exact place where they held space the previous day. Many individuals move long distances from the place where they were active on the preceding day.

Larger males tend to win wrestling matches. However, males are on the average smaller than females. Since larval males live in the habitats occupied by females, adult male body size is apparently not limited by larval energy limits. Hence we conclude that small adult male body size conveys advantages which may outweigh the disadvantage in wrestling matches. Some of the possible selection relationships countering large male size are discussed.

Females reject most mating attempts by males when they are active on the surface. They exercise no choice in mate selection following burrowing. Hence the mating system results in mating by the most persistent male followers and aggressive individuals able to hold the space above the place where the female burrows into the ground.

Two of the most important factors that contribute to the success of a parasite population are (1) the ability to find hosts and (2) the ability to oviposit in hosts when found. The theories of Thompson (1922, 1924), Nicholson (1933) and Nicholson and Bailey (1935), which have commanded attention in the field of population dynamics for a number of years, emphasized the importance of these factors in quite different ways.

Thompson assumed that the parasites have no difficulty in finding their hosts but have a constant egg supply whereas Nicholson assumed that the egg supply is virtually unlimited but that the parasites have a fixed and limited searching ability which he called their ‘area of discovery’.

Megarhyssa atrata F., the largest hymenopteran parasitoid known, is found in the holarctic. The stylus of its ovipositor can reach a length of 142 mm, the longest of all known genitalia in Arthropoda. This pimpline parasitizes its host, Tremex columba L., at a great depth in wood. Valvulae 3, which are always shorter than the stylus, are characterized on their outer side by abundant trichoid sensilla of three different types, and on their inner side by a dense layer of cuticular spines probably used in cleaning and shielding the stylus while at rest. The joint region between stylus and abdominal segments is richly equipped with mechanoreceptive trichoid and campaniform sensilla. The ovipositor canal is located between the two valvulae 1 which are separate for their entire length and supported proximally by the two valvulae 2 which are joined to each other from the base. The distal end of the stylus, shaped like an indented lancet, has secretory pores, the first such to be observed in Hymenoptera, from which accessory gland secretions flow. These secretions reach the end of the stylus by intravalvular canals in valvulae 1 and 2. These substances, which may cause cell lysis and also act as lubricants, can accumulate among the tens of thousands of cuticular formations distributed along the stylus which are thought to be surface storage cavities for the secretions. The sensory equipment of the stylus consists of six rows of approximately 200 mechanoreceptive campaniform sensilla. The ovipositor of M. atrata is thus characterized by almost exclusively mechanoreceptive sensory equipment; chemical stimuli appear to be monitored by two types of trichoid sensilla on valvulae 3. The finding that secretory pores occupy exactly the same sites as chemoreceptors in Ichneumonidae, Chalcidoidea, and Proctotrupoidea demonstrates the importance of studying the ovipositor of this parasitoid adapted to withstanding extreme pressures as it penetrates deep into wood.

Organophosphorus sprays were applied during 1968 and 1969 to an unsprayed but otherwise well cared for apple orchard to destroy the resident phytoseiid predators, Typhlodromus caudiglans Schuster and T. pyri Scheuten. The phytoseiid commonly found in commercial orchards in British Columbia, T. occidentalis Nesbitt, was then released into the orchard.The population density of T. occidentalis increased greatly during 1970 but in the absence of sprays the resident predators reappeared. By the end of the 1971 season, T. caudiglans and T. pyri were once again the main phytoseiid predators and T. occidentalis was relegated to an insignificant role.

The influence of temperature on the development of immature stages of Bracon mellitor Say, a braconid parasite of the boll weevil, Anthonomus grandis Boheman, was studied at a series of constant and variable temperatures. Resulting developmental rates and times were compatible with recent advances in the theory of thermal responses exhibited by poikilotherms. Mean development times recorded were in close agreement with predictions calculated from a previously derived absolute reaction rate development model.

Bracon mellitor cohort developmental data were also checked against a prototype stochastic cohort development model. In this comparison, observed and predicted probability distributions agreed for constant and variable day/night temperature regimes but showed some differences under sinusoidal temperature regimes.

Aggregating habits and seasonal occurrence of two species of deer nasal bot flies (Cephenemyia apicata and C. jellisoni) were studied through two seasons in California. Males aggregated at upper hillside and summit stands of Castanopsis sp. and Quercus sp. rising 2-10 feet above the top of surrounding scrub vegetation. Activity began at 20 °C. air temperature and ended soon after mid-day.

Intraspecific and intrageneric chasing by male flies is described and the spacing of flies at different sites is discussed. C. jellisoni males appeared to dominate males of C. apicata at these sites or, when both were present, their activities were stratified. Marked males tended to remain at a specific site throughout the day's activity.

In one observed mating, the flying pair united above the aggregation site and dropped in tandem to the vegetation below. A comparative description of the internal reproductive system of female C. apicata is given.

The dosage–mortality relationship of a multi-embedded nuclear polyhedrosis virus was determined for each instar of the bertha armyworm by probit analysis of mortality following the ingestion of polyhedral inclusion bodies (PIBs) placed on the surface of an artificial diet. Susceptibility to infection decreased as larvae aged; the median exposure doses (LE50) increased from 18 PIBs/larva for the first larval instar (L1) to 21 × 106 PIBs/larva for half-grown L6. When given equivalent doses, the time for infected insects to die increased with the age of the larvae. Within any given instar the length of time to death shortened with increasing doses. Larvae that survived to become adults showed no signs of infection. There was no evidence that any infected individual could recover from infection. From the data presented, calculations show that maximum production, 2.90 × 109 PIBs/treated insect, is achieved by feeding 10,000–20,000 PIBs/larva to young L5. Larvae dying as L6 have about 40% of their normal dry weight of essential tissue converted to PIBs. Although this MNPV currently would not be cost effective as a spray for protecting crops from bertha armyworm damage, its potential as a biocontrol agent, applied in small amounts at an early stage in bertha armyworm outbreaks, should be evaluated.

In Quebec apple orchards, pheromones are used to monitor a number of pest species (Rivard et al. 1978; Paradis et al. 1979). However, few studies have looked for the presence of sex pheromones in mirids. Scales (1968) detected the presence of sex pheromone in a mirid, Lygus lineolaris (P. de B.), as did Strong et al. (1970) for Lygus hesperus Knight. Subsequently, the daily and annual cycles of pheromone emission in Distantiella theobroma (Dist.) (King 1973) and Helopeltis clavifer (Walker) (Smith 1977) were established.

From 1985 through 1995, burlap flaps were stapled to 100 trees in a 10 by 10 grid in a 4-ha forest plot. Each year, the number of fourth- to six-instar larvae of gypsy moth, Lymantria dispar L., under each burlap flap was recorded at least weekly in June and into July. From 1987 through 1990,100 000–120 000 hatching gypsy moth larvae were released near the center of this plot in early May at the time of natural hatch. In the 4 years that releases occurred, there was a distinct, single cluster of large larvae under the burlap flaps near the center of the plot. This pattern did not occur in other years. Results are interpreted to mean that total dispersal of larvae from first to ultimate instar is limited, even though first instars are readily dispersed by wind.

Keys, descriptions, and illustrations are presented for the identification of the larvae, pupae, and adults of the four species of black flies known from Iceland, viz. Prosimulium (Prosimulium) ursinum, Simulium (Psilozia) vittatum, S. (Eusimulium) aureum, and S. (E.) vernum. Maps depicting their distributions within that country, and brief biological notes are given.

So many observations verging on the extraordinary and bizarre have been made of insect behavior that we no ionger are surprised to learn of insects appearing out of their normal environment. It is thus with interest rather than wonder that we note a few scattered references in entomological literature to thrips, normally considered phytophagous and to some extent predaceous, attacking man in a transitory manner.

Problems associated with quantitative estimations of mixed populations of several species of predators on apple trees are discussed. The problems arise largely because of the inherently high variability in such populations and because of the mechanical difficulties of counting predators on some basic unit of tree. In this investigation two devices used in sampling are described and their efficiency rated. One, a vacuum sampler, that removed predators from samples of leaf clusters on the tree failed to meet the standards set. The other, called the shaker sampler, tumbled clusters about in a revolving wire screen cage to dislodge predators for counting. The amount of processing with this device to remove practically all predacious specimens was calibrated. When the shaker-sampler technique was applied to studies in two orchards it proved to be practical for quantitative estimation of predator populations per large limb. The error associated with estimations of the density of individual species was usually very high so that pooling of the results for several or all species was required to reduce the variance to an acceptable level.

A new species of Grylloblatta from the Coast Mountains of British Columbia and two new subspecies of Grylloblatta campodeiformis Walker from northern British Columbia are described and figured. The distribution of the species groups from the Rocky Mountain and Coast–Cascade Cordillera are indicated. An interpretation of the present distribution as a result of late Pleistocene and Holocene geological and climatic events is presented.

Stem galls of Diplolepis spinosa (Ashmead), usually found on the endemic rose Rosa blanda Ait., and root galls of D. radicum (Osten Sacken), usually found on the endemic rose R. acicularis Lindl., have become established on the cultivated rose R. rugosa Thunb. in Canada. Adults and galls of D. spinosa and D. radicum are described and compared with those of closely related species. Host records, damage, and distribution of both species are discussed as is the suitability of R. rugosa as a host. It is suggested that galls in urban habitats are being established by adults flying into cities from surrounding patches of endemic roses.

The herbivore-resistant synthetic maize BS9 (C4) was grown in three environments, namely, greenhouse with reduced UV light, greenhouse with supplemental UV light, and outside, and leaves at the three-, five-, seven-, nine-, and 10-leaf stages of development were fed to the European corn borer, Ostrinia nubilalis (Hübner). Larvae preferred younger leaves, and leaves grown under reduced UV light, in spite of the high levels of the defence compound 2,4-dihydroxy-7-methoxy-2H-1,4 benzoxazin-3 (4H)-one (DIMBOA). The low level of feeding on leaves from plants grown outside was associated with increased toughness and increased photochemically derived phenolic dimers that cross-link hemicellulose. Tender young maize plants have a low level of cell wall phenolics and depend on a toxin (DIMBOA) for defence. In older plants, DIMBOA levels are low, leaves are tough, and resistance is largely structure-based.

Buprestis aurulenta L. has become well known as an emergent adult from old or established structures, and many authorities have accepted the implication that development has been progressing since the materials were installed. Because of the length of time involved in some records. an alternative explanation of infestation hy later direct attack has been suggested. The latter unsupported view has caused confusion.

Preliminary tests showed that, though Nasonia vitripennis (Walk.) can be propagated on housefly (Musca domestica (L.)) pupae at any stage of development, females parasitizing pupae less than 48 hours old, at 21.5°C., lived longer than those parasitizing older pupae. In view of the fact that the females always feed on the pupae after ovipositing on them, it seemed possible that the greater longevity of females parasitizing and feeding on young pupae had resulted from more suitable food provided by these pupae. As plans had heen made to investigate experimentally the host-finding capacity of this parasite species, it was essential that any effect of host age on this capacity, or on biological attributes of the parasite that influenced it, be standardized. Tests were therefore made to determine the effects, if any, of a host's age on the longevity and fecundity of female N. vitripennis laying and feeding on it.

In view of the increasing use of plant proteins as valuable alternatives to chemical insecticides, the susceptibility of pea aphids, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), to three purified mannose-binding plant lectins was determined in an artificial-diet bioassay. The insecticidal activities of a new lectin, APA (Allium porrum L. (Liliaceae) agglutinin) from garden leek, were compared with those of GNA (Galanthus nivalis L. (Liliaceae) agglutinin) from snowdrop and ASA (Allium sativum L. agglutinin) from cultivated garlic. GNA and ASA showed acute toxicity to first-instar nymphs; LC50 values for GNA and ASA were 350 and 700 µg/mL, respectively. With APA, mortality was scored only at high doses. In chronic experiments, however, lower doses significantly reduced survival and fecundity of adults (P < 0.05). Aphids fed a diet containing APA at 100, 500, and 750 µg/mL showed a significant delay in reaching adulthood and no aphids survived beyond 19 days of development. The data support the potential application of APA in the integrated management of insect pests.

During 1972, spruce budworm infested white spruce and balsam fir trees were sprayed aerially with a low dose of fenitrothion (0.25 oz AI/ac), entomopox virus (EPV) at 7.6 × 1010 polyhedra/ac, nuclear polyhedrosis virus (NPV) at 2.7 × 1011 polyhedra/ac, or each virus–fenitrothion combination. Fenitrothion (active ingredient), NPV, and EPV deposited at ground level at 5%, 31%, and 42%, respectively, of the amounts emitted.

In the year of application, NPV + fenitrothion was highly effective in population reduction and foliage protection especially on; balsam fir although a higher virus infection rate was found on white spruce than on balsam fir. EPV + fenitrothion also provided a high level of foliage protection and apparently reduced surviving female:male sex ratio to 1:2 compared with the normal 1:1 ratio. NPV + insecticide caused highest larval mortality, highest incidence of virus, lowest rate of moth emergence, fewest progeny, and lowest rate of progeny survival. The natural incidence of microsporidia was low in all plots.

In the year following application, the NPV + insecticide treated plot again showed lowest population density, highest larval mortality and incidence of virus, and low defoliation and egg mass density. However, there was a higher proportion of viable eggs deposited than in the previous year. Egg parasitism by Trichogramma minutum increased by 1.5 to 4.2% in plots treated with virus only and declined by 1.6 to 10.5% in insecticide treated plots and by 1.2% in untreated check plot. The transmission of the virus from one year to the next is considered to be of paramount importance in the future use of this pathogen in spruce budworm control.

Codling moth, Laspeyresia pomonella (L.), injury in a 14-ha apple orchard gradually increased in 1973 and 1974 despite the presence of 480 sex pheromone traps (1 mg trans-8, trans-10, dodecadien-1-ol per trap). Percentage injured fruit at harvest was 0.00075, 0.0062, and 0,033 in 1972, 1973, and 1974, respectively. Numbers of wild male moths trapped increased from 3e in 1973 to 64 in 1974.