Field populations of Lucilia cuprina (Wied.) in New South Wales were sampled for periods of 3 h on numerous occasions between 1975 and 1982 using West Australian blowfly traps. Ambient temperature, wind speed, relative humidity and solar radiation explained 77·4% of the within-day deviance of the catches. Temperature alone accounted for 74·9% of this deviance, indicating that the other variables, although significant, did not greatly affect trap catches. As air temperatures increased, log catch rates increased linearly up to 26°C and then remained constant up to 35°C. Wind speeds above 25 m/s caused a linear decline in log catch rates. Log catch rates increased linearly as solar radiation increased and decreased linearly as relative humidity increased. Changes in catch rates with time of day were explained almost entirely by the four weather variables, i.e. there was no evidence that intrinsic behavioural changes with time of day affected catch rates. The combined effects of the four weather variables accounted for 47·1 % of the between-day variation in trap catches. Trap catches that have been standardised, i.e. adjusted to a ‘ standard’ set of weather conditions, provide relative measures of population size which differ from absolute measures by a constant (unknown) scaling factor.

Biological control of Aonidiella aurantii (Mask.) is notoriously difficult in the hot lowlands of Swaziland and the eastern Transvaal. In view of resistance to organophosphates in populations elsewhere in the Transvaal, there is renewed interest in the commercial application of integrated pest management on citrus. Accordingly, data from a population of A. aurantii on orange trees in the Swaziland lowlands were examined to answer questions about biological control of the pest in this climatic region. Sections of the population on twigs and fruit were treated separately, and that on the leaves was ignored as not contributing much to the economy of the whole. The infestation of fruit each year depended largely on the size of the infestation on twigs in November (early summer), when crawlers from twigs first colonised the fruitlets. Mortality on twigs was estimated, checked from predictions of the recruitment rate and related to indices of climatic and biotic factors; 73% of the variation was described by mean predator intensity, mean minimum temperature and excess rainfall above the long-term mean, all measured over the generation time. On fruit, 32% of the variation in mortality was described by mean maximum saturation deficit in the generation time, the relationship being inverse. The dryness of the lowland climate appeared to be its favourable characteristic. The population appeared to be regulated about a mean level which was unacceptably high. Predators were the most effective natural enemies, probably followed by parasitoids (Aphytis spp.) on fruit. Endoparasitoids were probably ineffective.

Extracts from unsterile sheep fleeces seeded with Pseudomonas aeruginosa, Proteus mirabilis, Enterobacter cloacae or Bacillus subtilis equally stimulated oviposition by females of Lucilia cuprina (Wied.). However, with increasing length of incubation, significant differences emerged, the cultures of P. mirabilis, E. cloacae and B. subtilis becoming contaminated with increasing numbers of Pseudomonas aeruginosa and the responses of the flies to the culture extracts becoming greater. The maximum number of eggs was laid over four–g day–old cultures. The response was highly significant for Proteus mirabilis and E. cloacae but not significant for B. subtilis. Although contamination with Pseudomonas aeruginosa appeared to be the cause of the increased oviposition, pure P. aeruginosa cultures did not elicit high responses. The response to cultures of P. aeruginosa was apparently enhanced by interactions with other bacteria.

Copris diversus Waterh. is a brood-caring dung beetle from Africa, the females remaining in the nest with their brood balls until the young emerge. A technique was developed which allowed access to the nest without interrupting nesting behaviour, so that beetles and nest contents could be observed and dung could be added into or removed from the nest at specific times. At 27°C, if more dung was added to the nest in the first three days after the start of brood care, most beetles continued oviposition. Resorption of the terminal follicle started some time between the third and twelfth days of brood care, and while the terminal follicle was resorbing the beetles did not revert to breeding if supplied with additional dung. Subsequent follicles were also resorbed if brood care was allowed to continue beyond ten days, but their resorption did not impose a lengthy delay in breeding. Oviposition resumed 17 to 21 days after the start of brood care, irrespective of when the dung was added. Development of new follicles following follicle resorption took three to seven days, and thus the resorption of the terminal follicle must have taken about seven to fifteen days.

In studies in the Zambezi Valley of Zimbabwe, Glossina morsitans morsitans Westw. and G. pallidipes Aust. were captured on electric nets at various points around stationary targets. The distribution of flies was affected by wind direction, wind speed and the presence or absence of an attractant odour consisting of carbon dioxide and acetone. The distributions suggested that tsetse attracted to baits by visual stimuli alone fly first to a point just downwind of the baits, where the perception of odour is important in host recognition. Changes in the distribution of catches when odour was used suggested that the distributions could form useful indices of assaying attractant odours in the field. Data for Muscidae, Tabanidae, Asilidae and Hymenoptera are also presented.

A colony of Glossina morsitans morsitans Westw. was established in the laboratory in Tanga, Tanzania. After being expanded to the planned level of 60 000 flies, the stabilised colony was used to support a field trial using surplus males that were sterilised and released. The production system consisted of an adaptation of the in vivo rearing techniques developed at the Tsetse Research Laboratory, England. Goats were hosts for 90 % of the production; the balance was fed on rabbits. Techniques were developed to standardise the pupal off-take from stabilised colonies in each of three separate insectary units. Puparia were collected daily and kept separately until 52% emergence had occurred; these emerging flies, mostly females, were used to replenish the stock colony as needed. Further eclosion was prevented by chilling the remaining puparia (mostly males) quickly at 4°C and then storing at 10 ± 1°C for up to four days prior to irradiation and shipment to the field. About 68 % of the males produced were available for sterilisation. During the 15-month period of production in support of the field experiments, 1·3 million puparia were produced; 0·6 million of these puparia were released at a production cost of $220 per thousand.

In laboratory and field studies in southern England, the responses of adults of Chrysoperla carnea (Steph.) to various test materials were compared. Although the chrysopid, especially females, were especially attracted to hydrolysed and oxidised L- and D-tryptophan, they are unlikely to be attracted to crops by these compounds in Britain in sufficient numbers to control infesting aphids.

Natural enemies of Aonidiella aurantü (Mask.) were counted in suction-machine samples taken fortnightly over 41 months from an orchard of orange trees in the Swaziland lowlands, a region where biological control of the scale is difficult. Changes in the log population intensity/‘twig’ (Δ log N) of four species were, in each case, calculated over four thermal constants of 5000, 10 000, 15 000 and 20 000 hour– degrees above 12°C (h°>12C). The middle two constants were assumed to approximate to the thermal constants of the generation times of the natural enemies. For each natural enemy, Δ log N measured over each thermal constant was related by regression analysis to climatic and biotic indices to see how the interval over which population change was measured affected the conclusions. The longer the interval, the greater was the percentage of the explained variation in Δ log N, and the greater the number of indices that became significant. However at 20 000 h°>12°C, population change was measured over rather long intervals for short–lived species like Aphytis. At both 10 000 and 15 000 h°>12°C, the number and the identity of the significant indices in the regression tended to be the same. Consequently, conclusions about the factors affecting the natural enemies were based on these regression results. A. africanus Qued–nau, Comperiella bifasciata How. and Rhyzobius lophanthae (Blaisd.) responded directly to changes in their host's numbers, but Habrolepis rouxi Comp. responded inversely and was unlikely to have been effective. Furthermore, it was sensitive to high summer temperatures, as was A. africanus and possibly R. lophanthae. C. bifasciata was not sensitive to high summer temperatures but was adversely affected by the hyperparasitoid Marietta javensis (How.). None of the natural enemies was affected by prevailing saturation deficits.

The biology and host specificity of a South American moth, Acigona infusella (Wlk.), were studied in quarantine facilities in Australia. In choice tests on the host specificity of A. infusella, slight feeding by larvae occured on ginger, lettuce, banana, bullrush (Typha orientalis) and water primrose (Ludwigia peploides), but in starvation tests only waterhyacinth (Eichhornia crassipes) and pickerel weed (Pontederia cordata) supported complete development. A decrease in larval mortality and increase in egg-mass size of A. infusella occured when a microsporidian, Vairimorpha sp.; infecting the colony was eliminated, suggesting that these insects may then perform more effectively as biological control agents in Australia than in South America. The damage to waterhyacinth cause bu larvae of A. infusella may complement attack by other biological control agents already established in Australia.

A new species in the genus Phycita, the larva of which is a pest of eggplant in Nigeria and Senegal, is described and named P. melongenae sp.n. Notes on its biology and illustrations of the adult insect and genitalia of both sexes are given

The establishment and survival of larvae of Chilo partellus (Swinh.) on two sorghum cultivars in the six days after hatching was investigated in the field in India. During this period relatively few larvae are present outside the whorls of the plants, and the numbers present six hours and three days after hatching are proportional to the numbers hatching. The number of larvae in the plants declines during these first three days, but subsequently is stable. Some dispersal to adjacent plants occurs during this period and, at the plant spacing used, approximately seven plants were infested by larvae from a single egg-mass of 40 eggs. The relative susceptibilities of the two cultivars, IS 1151 and IS 2205, altered with the age and size of the plants. This is a vulnerable period in the life-history of the insect and attention should be focused on it in developing resistant cultivars, but because the susceptibility of the plants changes with age it is important to decide the age at which protection would have the greatest economic value.

Surplus puparia from a colony of about 50 000 females of Glossina morsitans morsitans Westw. provided males for sterilisation and release in an experimental assessment of the sterile insect technique in Tanzania. Excess males were stored late in the puparial stage at 10 ±1°C for up to four days prior to being irradiated at ambient temperatures in a nitrogen atmosphere with 11·8 krad in a radioactive caesium (137Cs) source. Puparia chilled at 8 ± 1°C were transported to the field release area twice weekly for manual release. At the release sites, the adults emerged synchronously within 60 min and were automatically marked as they crawled through sand containing fluorescent powder.

The climbing behaviour of newly hatched larvae of Chilo partellus (Swinh.) on sorghum plants was studied in the laboratory and in the field in India. The upward movement is directed by light, while the final downwards movement into the whorl is probably a response to the contrast of light above and dark below. Many larvae fail to reach the whorl, and success is reduced by high winds and rain, and by some physical features of the plants. Two sorghum cultivars, IS 1151 and IS 2205, differed in the extent to which larvae successfully reached their whorls, and their relative susceptibilities altered with age.

The flight performance of three cytospecies from the West African complex of Simulium damnosum Theo. was tested under controlled laboratory conditions. A total of 293 individuals (174 of S. squamosum (End.), 65 of a new form of the subgroup of S. soubrense Vajime & Dunbar and S. sanctipauli Vajime & Dunbar and 54 of S. sirbanum Vajime & Dunbar) was tested on 526 occasions, of which 380 involved sucrose-fed insects, 65 water-only-fed insects, of both sexes, from laboratory-emerged stock and 81 blood-fed, wild-caught females. A high percentage of tests resulted in flights. Frequency distributions of both flight duration and distance flown were skewed, more flights being of short than of long duration. Sucrose-fed females and females caught wild at human bait generally flew well. Insects given access to water only made short flights, but S. sirbanum flew fairly well under these conditions. The recorded maximum flight durations and distances were 262 min (in a male) and 5·25 km (in a female) in S. squamosum, 282 min (in a male) and 6·15 km (in a male) in S. soubrense/sanctipauli, and 186 min (in a female) and 5 27 km (in a female) in S. sirbanum, all from sucrose-fed groups. Some insects were flown on several days up to 11 days after emergence. Some insects made long flights on one day but not on others. Further long flights could be induced on the same day if the insect was allowed access to sucrose solution prior to retesting. These results are discussed in relation to previous findings from S. ornatum Mg. s.l. and to the migration potential of the important vectors of onchocerciasis in West Africa.

A survey of the phlebotomine sandflies in and around Kuwait City (Kuwait) was made during May and June 1981. Three species were found associated with human habitations: Phlebotomus papatasi (Scop.), P. alexandri Sinton and Sergentomyia antennata (Newst.). Sandflies were more abundant in newly developed areas on the periphery of the city than in the central or well-established areas. The five species in the phlebotomine fauna of Kuwait are reviewed and compared with those in adjacent countries. The relationship between the distribution of sandflies and building development is discussed and related to the recent increases in leishmaniasis cases in Kuwait. It is suggested that P. papatasi is the local vector of cutaneous leishmaniasis.

The two weevils Ceutorhynchus geographicus (Goeze) and C. larvatus Schultze, which live and develop on Echium plantagineum (Boraginaceae) in the western Mediterranean regions, are potential biological control agents for this plant, which is an important weed in Australia. Adults bite holes in the leaves and petioles, but this damage is not great in comparison with that caused by their larvae, which mine the collar and root, causing massive necrosis and often the death of the plant. C. larvatus larvae are found especially in the aerial parts of the collar of the plant, while those of C. geographicus attack principally the rootstocks. Quarantine safety testing was based on plants selected by the criteria already used for the Echium leaf–miner Dialectica scalariella (Zell.), and it was confirmed that the two weevils would be safe and effective agents for the biological control of E. plantagineum in Australia.

Cyrtobagous singularis Hust. was recorded from Brazil, Paraguay, Uruguay and Argentina in association with six species of Salvinia (aquatic ferns). Field observations and laboratory studies in Brazil and Australia showed that C. singularis severely damaged S. molesta and that the weevil is suitable as a control agent for this weed in tropical and subtropical areas in Australia. In host-specificity studies using 46 plant species that occur in Australia, development of the immature stages took place only on S. molesta. Minor leaf scarring occurred on sweet potato when in contact with water, but starvation tests excluded this plant as a possible terrestrial host. Adults fed, but were unable to reproduce, on water lettuce (Pistia stratiotes). The high degree of host specificity indicated that establishment of this weevil in Australia is without risk to non-target plants. C. singularis was first released and became established in Australia in 1980.

One–dimensional slab polyacrylamide gel electrophoretic techniques, staining systems and isoenzyme banding patterns for 14 soluble enzymes separated from crude homogenates of individuals of six species of cereal aphids (Sitobion avenae (F.), S. fragariae (Wlk.), Metopolophium dirhodum (Wlk.), M. festucae (Theo.), Rhopalosiphum padi (L.) and R. maidis (Fitch)) are described. The value of the techniques and banding patterns to taxonomic and population genetic studies of these and other aphid species are briefly discussed. With the six species, it was possible to separate the different genera as well as individual species within genera. The enzymes found to be most useful for inter–generic and/or -specific separations were adenylate kinase (AK), esterase (EST), glucose-6-phosphate dehydrogenase (G-6-PDH), hexokinase (HK), malate dehydrogenase (MDH), peptidase (PEP), phosphatase (PHOS), phosphoglucomutase (PMG), 6-phosphogluconate dehydrogenase (6-PGD) and sorbitol dehydrogenase (SORDH), whilst glutamate oxaloacetate transaminase (GOT), α-glycerophosphate dehydrogenase (α-GPD), malic enzyme (ME) and peroxidase (POD) were of relatively little taxonomic use. There were no banding pattern differences between the various morphs of S. avenae (first to fourth-instar nymphs, apterous and alate adults using the 14 enzymes.

A large–scale mating disruption trial for the control of Pectinophora gossypiella (Saund.) was carried out in the Fayoum Province of Egypt during the 1981 cotton season. Two areas, each of 50 ha, were sprayed with a microencapsulated formulation of the sex pheromone (a 1:1 mixture of (Z, Z)- and (Z, E)-1, 11-hexadecadienyl acetate) as the sole means of controlling this pest. Five applications of 10 g a.i./ha were made during the season using fixed-wing aircraft. The pheromone treatments were compared with conventional insecticide spray treatments in two other 50-ha areas of cotton. From comparisons of treatments in terms of various plant damage criteria including the percentage of rosetted flowers, percentage boll infestation, gross yield of seed cotton and lint quality, it was concluded that the pheromone treatment was equal in effect to the insecticide sprays.

A fast and simple method of preparing virgin females of Spodoptera littoralis (Boisd.) for exposure in the field is described. Low predation rates were achieved by tethering the moths on a short (20 cm) piece of cotton thread directly to the plants and by keeping unnecessary daytime exposure to a minimum. Consistently high levels of successful mating were recorded in both berseem and cotton fields in Egypt, suggesting the suitability of the tethering technique for measuring reduction of mating levels in pheromone control trials.