A key is given to the six genera of Signiphoridae including Rozanoviella gen. n. which is described to accommodate five congeneric species, three transferred from Signiphora and two from Thysanus. All are secondary parasites of Hymenoptera and Lepidoptera through Tachinids. The correct name of the type-species of Kerrichiella is shown to be Thysanus coleoptratus Kerrich.

In Lucilia cuprina (Wied.), cuticular bands are deposited most clearly on the mesothoracic post-phragmata, and up to ten such layers can be counted. The bands are deposited clearly only in response to fluctuating temperatures where the minimum temperature in a cycle falls below about 15·5°C. Growth bands are deposited whenever such a change in ambient temperature occurs and the deposition appears to show no inherent rhythmicity. The maximum width of the phragmata is more or less constant and the number of bands which can be distinguished depends upon how quickly the maximum width of the phragmata is reached. The rate of growth of the growth bands and their consequent width depends upon the maximum temperature experienced and the length of time the insect is maintained at that temperature in any cycle. Trials showed that the count of growth bands was an acceptable estimate of the actual age in days when temperatures rose 3·5°C or more above the threshold value of 15·5°C. With a greater temperature range, greater accuracy was achieved. The availability of protein food was shown to have little effect on the deposition of growth bands. A mean age in days was calculated for samples of field-caught flies of a uniformly young ovarian ‘age’ using the counts of growth bands and by working back in the temperature records from their sites of capture using the day-degrees method. Significant differences between the two estimates of age were taken to indicate the occurrence of developmental delays. These were attributable to shortages of protein food in the field and were associated with periods of drought. The method allows the demonstration that developmental delays have occurred but does not provide an accurate estimate of the duration of these delays. It does not permit the confident identification of delays imposed by shortages of oviposition sites.

Dieldrin, aldrin and γBHC in kerosene were applied topically to adults of Cosmopolites sordidus (Germ.) collected from banana plantations with no history of insecticide application and from plantations that had been treated regularly with dieldrin for many years. Adults from the latter source were highly resistant to dieldrin and aldrin, while resistance to γBHC was lower; those from the former source were susceptible and the results could be used as base line data. Females collected in spring from two untreated plantations showed LD50 values for dieldrin varying by a factor of 1·5, while females collected in the spring were 1·7 times more susceptible than those collected in the autumn from the same plantation. A discriminating dose of 1 μl of 1·0% dieldrin per weevil is considered suitable for detecting resistant individuals.

Chemical inhibition of feeding has been studied in detail for only a few insect species, but inhibitory chemicals play a considerable part in host-plant selection by a wide range of phytophagous insects from several orders. Many different chemicals are involved, some of them amongst the normal constituents of plants. A few have a general effect, preventing feeding by all the insects which have so far been tested, but the majority are effective only against some species.

Inhibition may function by blocking the input from receptors normally responding to phagostimulants or by stimulating specific ‘deterrent’ cells. The former may have a general effect on all insects, but chemicals in the latter category will only be effective if the insect has neurones capable of responding to them. Hence these will have more specific effects.

Inhibitory chemicals may be applied to plants in the same way as insecticides, their advantage being that the parasite/predator complex of species not feeding directly on the plant will be unharmed. An alternative approach is to breed resistant varieties of plants by selecting for inhibitory attributes. Although many varieties of crops are known which are insect-resistant, the basis of the resistance is generally unknown. A more thorough understanding of the mechanisms involved in inhibition of feeding by chemicals would enable a more logical approach to be made to the development of resistant plants.

The male accessory glands of Glossina austeni Newst. contain an apical secretion—a dense, opaque, whitish secretion at the apical end of the gland, and a diffuse secretion—a bulkier, more mobile, translucent, whitish secretion occupying nearly all the remainder of the gland. There is also a plug of clear solidified accessory material preventing the outflow of secretions from the resting gland. By immersing the whole accessory gland in a saline medium at pH 2·2, and then transferring the specimen to distilled water, the apical secretion can be separated manually from the rest of the gland, as an apical body. Measurements of the apical body in virgin male flies show that the apical body increases in width according to the equation: Age ≐ constant Χ width 2.5, but individual deviations from this relation were considerable. Immediately after mating the apical body is long and thin; recovery to approximately the resting condition is complete after 48 h, but, on average, mated males have thinner apical bodies than virgin males of the same age. The use of apical secretion measurements to assess mating frequency under field conditions might be possible if adequate samples of males were available.

An Agar/Parafilm membrane system, developed for feeding tsetse flies, was evaluated by comparing membrane-fed and goat-fed female Glossina morsitans morsitans Westw. with respect to the following: fly weight, meal size, trypsin levels and amount of protein in the posterior midgut, and the portion of midgut protein which is in the posterior midgut. In flies having the same prefeeding history, the digestive physiology of membrane-fed flies was not significantly different from those fed on goats. The offspring of membrane-fed flies were lighter, took smaller meals, and had less trypsin and protein in the posterior section of the midgut than did flies from the stock animal-fed colony. However the relationship between trypsin levels and protein in the posterior part of the midgut was the same in flies from animal-fed and membrane-fed colonies.

Diclidophlebia eastopi Vondráček and D. harrisoni Osisanya are pests of the timber tree Triplochiton scleroxylon in Nigeria. The egg and five nymphal instars are described and illustrated. Under laboratory conditions the life-cycle (egg-egg) of D. eastopi was completed in 18½ days, and mated fed females had a life span of 15 days. The sex ratio in the field was 1:1. Nymphs feed near the veins of mature leaves, causing premature leaf fall; adults feed on leaves of any age and cause no symptoms. Fecundity averaged 502 eggs, with a daily oviposition rate of 38; most eggs are laid in batches along the veins of mature leaves. The life-cycle of D. harrisoni was 16 days; mated and fed females lived 10 days. The feeding of firstinstar nymphs near the margins of young leaves causes leaf tunnels to form, inside which the nymphs complete their development; adults feed only from young leaves. In the field the female:male ratio was 2:3. Fecundity averaged 131, with a daily oviposition rate of 31. Fertility improved with multiple matings. The eggs are laid singly, partially embedded in the epidermis, and only on young leaves.

The stage of egg formation and density of follicular relics enable Lucilia cuprina (Wied.) females to be sorted into 16 ovarian stages, covering the period from emergence to the beginning of the fourth ovarian cycle. The correspondence between the actual age of a fly and its stage of ovarian development was determined at constant temperatures. Where developmental delays were absent, “reproductive age” gave reliable estimates of actual age under both constant and fluctuating temperature regimes. In the field protein shortages and lack of oviposition sites may prolong the time required to complete each ovarian cycle, and flies will be older than their ovaries would indicate. In practice the ovarian stages described provide estimates of minimum age for L. cuprina females.

A method is described by which Culicoides variipennis (Coq.), C. riethi Kieff. and C. nubeculosus (Mg.) have been maintained as laboratory colonies for over five years. Techniques are given for the maintenance of adults, larvae and pupae; with some modifications these could probably be applied to a range of other species. Adult midges were held in waxed card pill boxes, and provided with sugar solution. Anaesthetised mice provided a blood-meal source. Larvae were reared in pans on a substrate of glass fibre in a medium which contained nutrient broth, grass meal and Bemax. The life-cycle of these species occupies 10–21 days at 23–25°C.

The Eriophyid gall mite, Aceria chondrillae (G. Can.), which is distributed from south-east Russia to Portugal, was studied in the Mediterranean region as part of a biological control programme against skeleton weed (Chondrilla juncea) for Australia. The mite induces the vegetative and flower buds of Chondrilla to form leafy galls in which the full life-cycle is completed, causing stunting of the plant and reducing seeding. The mite overwinters in the rosettes of C. juncea without inducing gall development or reproducing. Populations decrease markedly during winter, recover in spring and infestations spread rapidly during summer. Reproduction is sexual and spermatophores are deposited by the males. Amblyseius sp. preys on A. chondrillae without marked effect. Tests made by placing fully developed galls of A. chondrillae on 75 species of plant including certain Cichoriaceae closely related to Chondrilla showed that the mite was highly specific to Chondrilla. Comparative tests with four geographical strains of A. chondrillae against six forms of C. juncea of various geographical origins indicated that the strains were specialised to their usual host form of the plant. A Greek strain of the mite readily attacked the main Australian form of C. juncea, and this strain has been introduced into Australia as a biological control agent for the weed.

The Australian species of the genus Heteropelma Wesmael (Anomaloninae) are revised. Three species, H. flavitarse (Brullé), H. scaposum (Morley) and H. perniciosum (Turner), are considered valid, and are redescribed. Two new synonymies have been proposed.

Techniques used in the radar detection and identification of individual flying insects are outlined, and laboratory and field measurements of the radar cross section of the desert locust, Schistocerca gregaria (Forsk.), are presented. The cross section was strongly aspect-dependent, and had an average value of approximately 1 cm2 at a radar wavelength of 3·2 cm. An example is given of the periodic fluctuation in radar cross section (the radar ‘signature’) produced by locusts in free flight, and the spectral contents of the signatures obtained from 35 laboratory-bred free-flying locusts are described. The fundamental components of the signatures, presumed to be at the wing beat frequency, were closely grouped about 23 Hz. It is suggested that the feasibility of using radar signatures as a means of insect identification will largely depend on the degree to which the species of interest are characterised by specific wing beat frequencies. Estimates of locust flying speed and heading deduced from photographs of locust and balloon radar tracks produced a mean value of 5·3 m s-1. Undetected small-scale flight manoeuvres may introduce negative errors in the estimation of flying speed. It is concluded that radar will provide unique observational facilities for the entomologist but that the limitations introduced by the problem of target recognition have yet to be defined.

A pheromone trap is described which records the exact time individual male moths enter a trap. This apparatus was operated for approximately three months at two sites in Cyprus. Continuous recordings were made of wind speed, wind direction, temperature and relative humidity near the trap site. Males of Spodoptera littoralis (Boisd.) were generally attracted to a trap baited with S. littoralis virgin females for the first two to three hours after dark. Males of S. exigua (Hb.) arrived most frequently at a trap baited with S. exigua females between 03.00 and 04.00 h. A relationship between wind speed and numbers of males of S. littoralis recorded was found at one site; for winds at a height of 1–37 m varying between 0·8 and 5·2 m s-1, increased wind speed resulted in an increase in the numbers of males recorded. Increase in relative humidity at one site was associated with a decrease in the number of males recorded. No apparent relationship was established between temperature and the number of males recorded, other than the fact that below 13°C many fewer males arrived at the trap. The implications of these findings in relation to movement of adult male S. littoralis are discussed.

In this ecological survey conducted mainly in western Tanzania between 1962 and 1969, six species of Earias were found, including two undescribed species and E. cupreoviridis (Wlk.), which is restricted to Sida spp.; E. biplaga (Wlk.) and E. insulana (Boisd.) were the only species found on cotton and were virtually restricted to Malvales. Differences in the incidence of Malvales and the Earias larvae feeding on them were noted on a research farm and on surrounding local farms as being due to different farming practices and soil types. E. biplaga was the dominant species on cotton for most of each year and its major alternative host was Waltheria indica; E. insulana was relatively more common on cotton in the dry season and was particularly common on Abutilon spp. Populations of E. biplaga increased on W. indica early in the rainy season, then dispersed onto cotton; populations on cotton could be predicted from the size of earlier populations on W. indica and subsequent rainfall.

In the Jordan Valley of Israel, spread of tomato yellow leaf curl virus in tomatoes by Bemisia tabaci (Gennadius) was delayed by three field treatments: (1) a straw mulch at the time of sowing; (2) sprays every four days with azinphos-methyl or methidathion; and (3) a combined treatment of a straw mulch after germination plus azinphos-methyl sprays at four-day intervals starting ten days after germination. The protective effect of straw mulch lasted about three weeks, and then sharply declined. In laboratory tests adult whiteflies were attracted more to straw than to tomato leaves, and more to fresh (yellow) straw than old (grey) straw exposed to field conditions for 25 days.

In Rhodesia, field studies were made of the initial attraction of G. morsitans morsitans Westw. and G. pallidipes Aust. to mobile and stationary baits, using flight traps which surrounded baits or which were placed in the densest part of the attracted swarm. With stationary baits, many flies were attracted by host odour and visual stimuli assisted final orientation. With mobile baits, many flies were attracted by visual stimuli alone; odour did not increase attraction. With both mobile and stationary baits, there was no indication that major hosts are much more effective than minor ones as initial attractants, although stationary men were exceptionally poor baits, for G. pallidipes especially. The sex and species compositions of catches from stationary baits other than men were representative roughly of the inactive population—70% females of both species, and a roughly 1:4 ratio of G. morsitans to G. pallidipes. The sex and species compositions of catches from all mobile baits were biased—40% female G. morsitans, 60% female G. pallidipes, and a roughly 2:1 species ratio. Nearly all flies attracted to stationary baits were hungry whereas 10–25% of both sexes visiting mobile baits had fed recently. The use of a variety of electrocuting devices showed that compact persistent responses and alighting reactions of attracted flies were evident more for males than for females, more for G. morsitans than for G. pallidipes, more near model animals with host odour than near odourless models, more near models than near men, and more with tenerals and hungry non-tenerals than with recently fed flies. Men with mobile baits depressed greatly the alighting reactions and with stationary baits men inhibited greatly the initial attractions. Both effects of men were greater with females than with males and greater with G. pallidipes than with G. morsitans. Men were recognised by their upright appearance and odour. Only desperately hungry flies probed men whereas less-hungry flies probed an ox with men. Food-seeking flies of differing nutritional state were not shown to distinguish between mobile and stationary baits. Although the results support the conventional view that mating and feeding functions in the response to hosts occupy distinct phases of the hunger cycle, it seems necessary to modify the conventional view by placing more emphasis on the role of mobile baits as food sources and by envisaging a definite mate-seeking response by mature females.

Field studies with Glossina morsitans morsitans Westw. in Rhodesia showed that hand-net catches can reduce slightly the responses of males to mobile baits and can reduce female responses by three-quarters. Description is given of methods of operating baits in the absence of men and of methods of electrocuting flies as they fly near baits, alight on baits and respond to decoy tsetse. These techniques are more efficient and objective than hand-net catching.

To elucidate the host preferences of tsetse, an observer followed animals as they wandered in woodland infested with Glossina morsitans morsitans Westw. From 55 to 88 landings by tsetse and 0·2–3·0 engorgements were seen per hour on ox, dog, bushpig and adult warthog, as against 14 landings and no engorgements on warthog 2–5 months old and 0·3–1·7 landings and no engorgements on impala and bushbuck. Many of the landings and most of the engorgements on adult suids occurred near the eye but this region was not attractive with other animals and young warthog. Unsuccessful attempts were made to determine the attractive stimuli from the eye region of adult suids.

This paper reports the data for the uncommon Anopheles spp. from 24-h man-baited catches mainly in the Semliki Forest, Uganda, but also from the Zika and Mpanga Forests Anopheles (Cellia) nili (Theo.), A. (C.) marshallii (Theo.), A. (C.) demeilloni Evans, A. (C.) squamosus Theo., A. (A.) coustani Lav. s. str. and A. (A.) tenebrosus (Dön.) were rarely caught. A. (A.) obscurus (Grünb.), A. (C.) moucheti Evans and A. (C.) keniensis Evans were also scarce, but the numbers did indicate nocturnal and ground-haunting habits. Comparison of catches of the less uncommon species (A. (A.) ziemanni Grünb., A. (A.) paludis Theo., A. (A.) implexus (Theo.), A. (C.) funestus Giles, A. (C.) hargreavesi Evans and A. (C.) pharoensis Theo.) with those obtained by other workers showed them to be primarily ground haunting and nocturnal but with wide variation in their temporal distribution patterns.

A study was made between 1967 and 1971 at Edinburgh University and at EAVRO, Muguga, of the variability in feeding performance of all three instars of Rhipicephalus appendiculatus Neum., with a view to better prediction of transmissions of Theileria parva. Variability could be definitely ascribed to factors within the ticks only when vigour was reduced after prolonged storage and when mating opportunity was withheld from attached females. Lower environmental temperatures prolonged engorgement, but it was arguable whether this effect was produced through the tick or through the host. All other sources of variability arose from influences within the host. The most significant of these were recognised in responses by rabbits in which resistance had been induced by successive infestations. Resistance was manifested by prolonged engorgement, by a reduction in numbers engorged and in degree of repletion, and by an increasing severity in host reaction. Three resistance mechanisms were suggested by host reactions—one appearing at the earliest stages of attachment, a second with the deposition of cement, and a third at the start of salivation. Each varied in efficacy, and each was capable of arresting an infestation. Cumulative and synergistic responses were ascribed to interactions between these mechanisms. Storage periods, sizes of infestations and sex ratios of R. appendiculatus were standardised within routine procedures, and abundant records of previous and subsequent performances on rabbits and cattle are presented for comparison and reference. Comparison of feeding performances on different animals suggests that cattle, buffalo, eland, waterbuck and oryx are as satisfactory as hosts as the rabbit, whereas Thomson's gazelle, wildebeest, sheep and goat are less so. Immature instars successfully completed engorgement on mongoose, cane rat, genet, domestic fowl and spur-fowl.