Chrysocharis caribea sp. n., a parasite of agromyzid leaf miners, mainly of Liriomyza sativae Blanch, in the West Indies, and Emersonella palmae sp. n., parasite of Hispoleptis subfasciata Pic, a hispine leaf miner on oil palms in Colombia, are described. New generic and specific synonymies and new combinations are established in Chrysocharis Förster, Proacrias Ihering (=Didymotropis De Santis syn. n.), Chrysonotomyia Ashmead (=Achrysocharis Girault syn. n.), Teleopterus Silvestri, Pediobius Walker, Emersonella Girault, Euplectrus Westwood, Stenomesius West-wood, Diglyphomorpha Ashmead, Miotropis Thomson, Ardalus Howard and Grotiusomyia Girault. Additional taxonomic comments on Chrysocharodes Ashmead and Astichus Förster and tentative keys to the species of Proacrias and Emersonella are included. Lectotypes are designated for 24 specific names.

Tachinobia gen. n. is defined and T. repanda sp. n. and T. gradwelli sp. n., both of which are parasites of Taohinidae, are described and illustrated. Kocourekia clavigera sp. n., a parasite of Megachile, is also described. A tentative illustrated key to 17 genera of Tetrastichinae is given, with notes on all genera and details of hosts and geographical distribution for included species. One species, Quadrastichodella eucalypti, is probably phytophagous and is widely distributed on cultivated eucalypts.

The effects of host quality on the development of Gryon gnidus (Nixon), a scelionid egg-parasite of Acanthomia tomentosicollis (Stål), are reported. A minimum exposure period of 24 h at —4°C or an irradiation dose of 1000 rads from a cobalt-60 source killed 98–99% of freshly-deposited, fertile eggs of A. tomentosicollis. Sub-lethal periods of exposure delayed hatching in both treatments and the incubation period was increased from 4 days to 5–7 days in eggs exposed to freezing temperature and 4–7 days in irradiated eggs. About 44% of the fertile, untreated eggs hatched normally while 56% were parasitised by G. gnidus. The irradiated or frozen eggs did not hatch and were not parasitised by G. gnidus, thus indicating that G. gnidus would not parasitise dead eggs of A. tomentosicollis. The significance of these results is discussed.

A laboratory colony of Glossina morsitans morsitans Westw. which originated from puparia collected near Kariba, Rhodesia was more productive than another colony which originated from Handeni, northern Tanzania; during 1975, the former produced an average of 5–9 puparia per female and the latter 3–6. Although mortality in the Tanzanian colony was somewhat higher than in the Rhodesian colony, the main reason for the lower productivity of the Tanzanian colony was the much poorer fecundity of the females. This was associated with abnormalities of the reproductive system. The differences in laboratory performance between the two stocks were probably a reflection of their genetic diversity. Thus the Tanzanian Y chromosome is metacentric compared with the almost acrocentric Y chromosome of Rhodesian males, and some individuals carry small metacentric supernumerary chromosomes which are not present in Rhodesian flies. Giemsa C-banding showed band differences between the chromosome complements of the two stocks. Probably the most important difference, revealed by polytene chromosome analysis, is a large inversion in the X chromosome of Tanzanian flies, which, together with at least one band difference, is fixed in the homozygous condition. The possible evolutionary pathways of these mutations are outlined and their significance is discussed in terms of their distribution in nature and of the performance of the two strains in the laboratory.

Freshly formed (less than 1-day-old) pupae of Stomoxys nigra Macq. treated with gamma rays showed a linear-regression mortality-response with radiation exposure. Mature 5-day-old pupae did not show this effect and were considered more suitable for sterility studies. Flies emerging from both groups of treated pupae showed no deviation from a 1:1 sex ratio. Radiation inhibited fecundity. An exposure dose of 1000 R halved egg production and a dose of 2000 R almost stopped oviposition. Females from pupae exposed to 3000 R produced no eggs. Complete sterility of males was not achieved within the range of tested dosage; exposures of 3000 R and 4000 R induced 98–8 and 99–7% male sterility, respectively. Radiation reduced the longevity of both males and females. A dose of 3000 R did not impair either male mating ability or sexual competitiveness in small-scale laboratory tests.

In field collections of Diptera associated with approximately 12 000 cocoa flowers in Bahia State, Brazil, 66% of the total catch consisted of Cecidomyiidae, 33% of Ceratopogonidae and 2% of Chironomidae and Psychodidae. The ceratopogonid species collected included Forcipomyia (F.) sp., F. (F.) genualis (Lw.), F. (F.) harpegonata Wirth & Soria, F. (F.) pictoni Macfie, three species of Forcipomyia (Euforcipomyia) sp., F. (E.) bromeliae Saund., F. (E,.) quasiingrami Macfie or near species, Forcipomyia (Thyridomyia) jipajapae Wirth, F. (Warmkea) lesliei Wirth, F. (Microhelea) fuliginosa (Mg.), Atrichopogon sp., Dasyhelea sp., Culicoides glabellus Wirth & Blanton and C. paraensis (Goeldi). There was some evidence that F. genualis or near species, Atrichopogon sp., Dasyhelea sp., and some species of Cecidomyiidae may pollinate cocoa. Of nine different organic substrates investigated as potential breeding sites, most species of Ceratopogonidae were reared from epiphytic bromeliads, rotting jackfruit, rotting banana stems and rotting cocoa pod husks.

A population of Aonidiella aurantii (Mask.) was studied on 72 Clanor orange trees in an orchard of 1800 15-year-old trees growing at an altitude of 280 m at Tshaneni, Swaziland. This orchard had not been sprayed with toxic chemicals for 18 months before observations started. Trees were banded with ‘Formex’ compound to control ants during the observation period which lasted from February 1972 to June 1975, and during which only nutritional and fungicide sprays were applied. Samples taken at 2–3 week intervals, measured three parameters: live adult female scale intensity on leaves, twigs and fruit; predation and parasitism levels; and adult parasite and predator intensities. A logarithmic transformation and 90% confidence limits showed that short-term fluctuations of adult female scales within each season were real, not due to sampling variation, and represented generations. These generations, more or less discrete in spring, became increasingly overlapped as the season advanced. Suction machine samples showed that the endoparasites Compendia bifasciata How. and Habrolepis rouxi Comp., were closely synchronised with these generations but were not otherwise density dependent. The hyperparasite Marietta javensis (How.) was more closely correlated with C. bifasciata than with H. rouxi. Aphytis spp. and total predator numbers apparently responded in a density dependent manner to seasonal scale increases. Predation predominated on twigs, Aphytis parasitism on leaves and fruit, while endoparasitism passively followed the adult female scale peaks, firstly on leaves and twigs, later in the season on fruit.

A method for making life tables is proposed, based upon the expression of stage duration and reproduction in terms of a physiological time-scale. For this purpose, stage duration and reproduction were measured on orange plants at ambient temperature in an insectary over one year. A development threshold of 12°C was established and stage duration expressed in hour-degrees (h°) above 12°C. The greatest factor affecting daily crawler production per female was reproductive age. Accordingly, based upon the per cent contribution of each reproductive age group to the rate of increase, r, only the first 35 days of reproduction were considered, and the mean crawlers/female/day was plotted against over this period. Development and reproduction were fastest on fruit, slowest on leaves, and because the population behaved so differently on leaves, twigs and fruit, these sites should be analysed separately. Migration experiments showed negligible net exchange of crawlers between sites.

The genus Apodiphus Spinola is redefined on the basis of external structures and male and female genitalia and is compared with Paranevisanus Distant. This new definition of Apodiphus, based on its type-species, A. amygdali (Germ.), excludes A. pilipes Horváth. Neonevisanus Distant is synonymised with Apodiphus Spinola and the type-species of the genus Neonevisanus, (N. rugosus Dist.) is synonymised with A. integriceps Horváth. Neonevisanus pallidus Hoberlandt (=A. siazovi Kirich. syn. n.) is transferred to Apodiphus and A. amygdali, A. integriceps, A. pallidus and A. murghzarus sp. n. are described in detail, with illustrations. The species of Apodiphus feed on almond, apple and other deciduous trees. The genus ranges from Italy in the west to N. India in the east, generally at relatively low altitudes up to 1600 m. Its probable centre of origin is Iran, where three out of the four species are found. A. amygdali is the only European species.

The seasonal activity of the adults of 13 tick species was studied on cattle herds in the Central Province of Zambia from 1969 to 1972. The six main species, Boophilus decoloratus (Koch), Hyalomma marginatum rufipes Koch, H. truncatum Koch, Amblyomma variegatum (F.), Rhipicephalus appendiculatus Neum., and R. evertsi Neum. behaved as previously described for the Southern Province. R. compositus Neum. appeared from August, with peak numbers in September–October. R. simus Koch and R. tricuspis Dön. appeared from October, for seven months and three months respectively. R. supertritus Neum. and Ixodes cavipalpus Nutt. & Warb. had a brief activity season from November to January, and R. pravus gp. and R. sanguineus gp. were active from December to July. The distribution of ticks over the body of cattle was determined by fractionised collections, which gave reliable quantitative information for nine of the species. A limited number of collections from sheep, goats and dogs are analysed in relation to season. Collections from 127 wild animals, mainly along the escarpment and riverine bush of the Zambesi, are recorded.