Several new traps were designed and tested against Glossina morsitans morsitans Westwood and G. pallidipes Austen in Zimbabwe. The best of the new traps, the F2, was three times as effective as a beta trap and ten times as effective as a biconical trap for G. pallidipes. A white biconical trap was only half as effective as an F2 trap for females of G. m. morsitans. The catch of males of G. m. morsitans was similar in all traps. The F2 trap was up to ten times as effective as a beta trap for Stomoxyinae. Catches doubled when acetone was released at 0·5 or 5·0 g/h near the traps. Catches from traps made of white cloth declined by 90% as the cloth yellowed with exposure but were restored when the cloth was painted white.

Hollow-fibre, laminate-flake and microencapsulated formulations of the synthetic sex pheromone (a 1:1 mixture of (Z, Z)- and (Z, E)-7, 11-hexadecadienyl acetate) of Pectinophora gossypiella (Saunders) were compared in large-scale mating disruption trials in Egypt in 1982. Fifty-hectare blocks of cotton were treated at regular intervals throughout the season with the formulated pheromone as the sole means of controlling the pest. The pheromone treatments were compared with conventional insecticide spray treatments in other 50-ha blocks of cotton sited in the same localities. Comparisons of numbers of infested flowers and green boils, open boll counts, crop development, yield of seed cotton, lint quality and seed damage in pheromone-and insecticide-treated blocks, showed that adequate levels of control were achieved using the pheromone formulations, which were equal in effect to the insecticide sprays. Beneficial insects were found in greater numbers in the pheromone-treated areas than in areas treated with insecticides.

Bruchophagus muli sp. n. is described and compared to a similar Australian species, B. fellis (Girault). Both wasps attack citrus; B. muli galls the fruit of lime (Citrus aurantifolia) while B. fellis galls the twigs of a number of citrus varieties in Australia, including lemon, orange and grapefruit. B. muli appears to be restricted in distribution to the southern region of Papua New Guinea

Electrophoresis was used to characterize the esterases in Lucilia cuprina (Wiedemann). Of the 16 esterase bands visualized, only one was associated with resistance to organophosphorus insecticides. In laboratory reference strains, the esterase E3 was consistently found in both susceptible and heterozygously resistant flies, but was absent from homozygously resistant flies. It was postulated that resistant flies possessed a non-staining form of E3, designated E3null. Genetic analyses mapped the locus for E3null to a position in the same region as the gene for organophosphorus resistance. No recombinants between the genes for resistance and E3null were detected. In field populations of L. cuprina from several areas in Australia, a close association was found between the frequency of E (0·97) and the proportion of flies resistant to organophosphorus insecticide (0·967). This association suggests that E3null represents the product of a major resistance gene in terms of the ‘mutant ali-esterase’ theory. E3 as found in susceptible blowflies, represents the ‘original’ ali-esterase, the gene for which mutated to one coding for E3null. This mutant enzyme can hydrolyse organophosphates more efficiently than E3 but has lost the ability to hydrolyse 1- and 2-naphthyl acetate (the substrates used to visualize the esterases after electrophoresis).

Pseudococcus mandio sp. n. is described from the roots of cassava in Paraguay, Bolivia and Brazil. In Paraguay, it is probably associated with wilting of the plant and, in common with most mealybugs, it appears to be a phloem-feeder. There is evidence of sufficient phloem in the roots, and this may be identical with the phloem of the stems. The mealybug is related to P. affinis (Maskell) in possessing swollen hind femora with numerous translucent pores, and discoidal pores around the eyes, but the oral rim ducts are either few or absent entirely.

An ecological study of summer populations of Metopolophium dirhodum (Walker) on winter wheat, was carried out near Bedford, UK, in 1978–80. Alate production (as percentages of alatiform fourth-instar nymphs) followed a consistent and synchronous three-phase pattern: with increases to 50% in early June in 1978–80 and 90% in late July in 1978–79. The proportions of winged offspring deposited by apterous parents also showed a similar increase, changing from 5% on 14–20 June to 91% on 5–11 July. Alate parents deposited mostly (75%) wingless offspring. Frequency distributions for nymph batch sizes were obtained for both morphs in 1979. Alate deposition was bimodally distributed. For apterous aphids, the fourth instar was the main dispersal stage. The numbers of adult apterae expressed as proportions of the total population were generally lower in 1979 than in 1978. The numbers of colonies increased sharply between 19 and 21 June in 1978 and 1979, and remained at similar levels to each other until at least 5 July. Colony and population numbers were highly significantly correlated over certain periods in 1978 and 1979. Colonies with >20 aphids increased sharply in numbers after 6 July, probably as a result of changing aptera dispersiveness. An estimate of mean colony size in 1979 showed a well-defined 14-day plateau phase. Changes in population alate production and changes in the proportions of winged offspring (from apterous parents) are discussed in relation to colony development. It is considered that increases in colony size produce colony-specific patterns of alate production.