Cephalonomia stephanoderis Betrem and Prorops nasuta Waterston are two bethylid parasitoids obtained from Africa for the biological control of the coffee berry borer, Hypothenemus hampei (Ferrari) in Mexico and Ecuador. Rearing methods and life-cycle studies carried out under controlled conditions are described for both the parasitoids and H. hampei. Scanning electron micrographs are shown of the developmental stages of the parasitoids. Data are given on development times, pre-oviposition period and on the mating and oviposition behaviour of C. stephanoderis.

Endosulfan resistance in the coffee berry borer Hypothenemus hampei (Ferrari) was discovered in New Caledonia after six years of lindane and 12 years of endosulfan biannual applications. The direct spray technique was used to study cross resistance with lindane and to monitor resistance to both pesticides in 15 regions of New Caledonia. An easier monitoring technique was developed for early detection by field laboratories. Results from this simple method, using twice the LC99 of endosulfan to susceptibles (400 ppm) showed a comparable distribution of resistance to the direct spray method in five regions where resistance was detected. The percentage of surveyed fields containing resistant insects in these areas was: Poindimié, 100%, Ponérihouen, 97%; Touho, 63%; Houailou, 10%; Hienghène, 6%. Resistant insects were significantly more frequent in the new sunny fields than in older shady plantations (P<0.05), and fields with endosulfan used in the preceding year (P<0.001). The possible reasons for the observed distribution of resistance are discussed.

Population densities of mealybugs and other honeydew-producing Homoptera were assessed in six cocoa (Theobroma cacao Linnaeus) trials by inspecting trees from ground to eye level, and also by dissecting samples of terminal buds. A total of 68 cocoa progenies was examined, mainly inter-crosses of six clones. Progenies differed in their levels of infestation with total mealybugs, Planococcoides njalensis (Laing), Planococcus citri (Risso), Phenacoccus hargreavesi (Laing), (Pseudococcidae), Toxoptera aurantii (Boyer de Fonscolombe) (Aphididae), and Mesohomotoma tessmanni (Aulmann) (Psyllidae). Crosses with Amelonado or T63/971 were generally more densely infested with mealybugs than those for example of NA34 and T63/967. Trees of T17/524 parentage were sparsely infested with mealybugs. Rankings of progenies by infestation with mealybugs from the two different sampling procedures were positively correlated, but the relative abundances of individual mealybug species on the trunk and in the canopy differed. Several species of mealybug found in buds were either rare or never found by inspecting trees up to eye level. Correlations between rankings of progenies by order of abundance of Planococcoides njalensis and Planococcus citri were positive and statistically significant, as were those between mealybugs and infestation of buds by T. aurantii or M. tessmanni. The above rankings were negatively correlated with those by aphid and psyllid abundance assessed from inspecting trees up to eye level. The two sampling procedures were complementary but, for economy, samples of buds gave the clearest indication of a progeny's suitability for mealybugs.

The relative attractiveness of coloured sticky board traps to the carrot fly (Psila rosae (Fabricius)) is described by a model in which fly catch is related positively to the amount of light reflected from the trap in the green-yellow (550–570 nm) band of the spectrum and negatively to the amount reflected in the violet-green (390–550 nm) band. The model allows the performance of new coloured traps to be predicted solely from spectral reflectivity measurements. Similar numbers of carrot flies were caught/unit area on traps varying in size from 150 cm2 to 4800 cm2. Most flies were caught on traps resting on the ground. The number of flies caught was reduced by 0.84% for each cm the trap was raised above 10 cm from the ground. One-sided sticky traps angled at 45° to the vertical doubled the numbers of carrot flies caught/unit trapping area and reduced by 90% the numbers of non-target species caught.

The distribution of introduced parasitoids of Phthorimaea operculella (Zeller) in Victoria is described. Apanteles subandinus Blanchard and Orgilus lepidus Muesebeck were most abundant, but Copidosoma koehleri Blanchard was also recorded from several sites. Detailed analysis of data obtained through regular monitoring revealed that, in an area free from insecticides, parasitoids were a major factor in controlling P. operculella. This result differs from previously published opinions on the effect of parasitoids, and is attributed to the analysis of data, in this study, on a generational basis. The effect of insectide applications on P. operculella and its parasitoids is discussed.

The CLIMEX model for matching climates in ecology is used to forecast the favourableness of the Australian environment for Diuraphis noxia (Mordvilko). Parameters used in CLIMEX for D. noxia were derived from the literature and tuned by iterative matching with the known distribution of the aphid in North America. These fitted values were then validated using the known distribution of D. noxia in southern Africa, and with the country-by-country occurrence of the aphid around the world. The results suggest that the drier inland parts of the Australian wheat belt would be very favourable for D. noxia growth and survival. A computer model of the interactions between climate, wheat growth and the biology of D. noxia was then used to simulate the likely infestation rates and potential yield reductions at selected sites in both the summer and winter rainfall regions of the Australian wheat belt. The results indicate that D. noxia has potential to cause severe losses to the wheat crop should it arrive in Australia.

Previous investigations showed that (1) predatory mites use odours volatilizing from spider-mite infested plants for remote prey selection and (2) the response to the volatiles is correlated to the predator's ability to control populations of the prey species. Based on this correlation, it is hypothesized that preselecting predatory mites with the aid of olfactometer experiments will increase the probability of finding an efficient natural enemy. Y-tube olfactometer experiments with 11 species of phytoseiids showed that only four species were attracted by the odour of cassava leaves infested with cassava green mite Mononychellus tanajoa (Bondar). If the hypothesis mentioned above is valid, the probability of finding an efficient natural enemy within this group of four will be higher than finding one by randomly taking a species from the initial group of 11 species. Since testing of phytoseiids with an olfactometer can be done in a few hours, it is suggested that these tests precede more laborious evaluation methods.

Afroryzophilus djibai is a new genus and species of weevil, which attacks rice in Senegal. Its biology, pest potential and relationships with other Erirhininae are discussed.

Simulium metallicum Bellardi larvae were collected from a variety of sites in the three onchocerciasis foci in Mexico. Their head patterns and body coloration were scored before the larvae were cytologically analysed. Cytotypes A, B, H and I were collected and in the majority of cases they could be distinguished from each other by larval morphology. An undescribed cytotype (termed cytotype X) was found in Oaxaca which, on the basis of larval morphology, was indistinguishable from cytotype B.

The susceptibility levels of Mansonia bonneae Edwards larvae to Bacillus thuringiensis israelensis (B.t.i.) SkeetalR, B.t.i. BactimosR briquettes and Bacillus sphaericus RB80 were evaluated under field conditions. Satisfactory control of larvae was achieved during 24 h–48 h post-treatment. At 72 h after treatment with a 48 h exposure period, over 90% reduction was achieved by SkeetalR at both applied dosages and by B. sphaericus RB80 at the higher applied dosage. BactimosR briquettes achieved less control at both applied dosages, due to slow, sustained release of B.t.i. spores. SkeetalR and B. sphaericus RB80 released their toxic ingredients as early as 2 h after treatment, after which the spore counts (CFU/ml) increased steadily in the middle and bottom water layers and reached maximum level at 72 h post-treatment. However, SkeetalR displayed very little residual activity as evidenced by the drastic decline of spore counts as well as larval reduction at one week post-treatment. By contrast, BactimosR briquette and B. sphaericus RB80 prolonged their residual toxicity throughout the four week period. The peaks of spore counts in the middle and bottom water layers for SkeetalR and B. sphaericus RB80 preceded the corresponding peaks for larval reduction rates by 24 h and 48 h and 1 week to 2 weeks, respectively. The spore counts of BactimosR briquette at the high applied dosage fluctuated closely with the reduction rates of larvae throughout the four week period.

Anagyrus mangicolasp. n., an encyrtid parasitoid of Rastrococcus species on mango in India, is described and compared with related species. The parasitoid has been the subject of laboratory studies and may be introduced into West Africa to supplement the activities of previously introduced natural enemies of the mango mealybug (R. invadens Williams).

Laboratory apparatus and techniques are described for the rearing and insecticidal treatment of whitefly, Bemisia tabaci Gennadius, under simulated field conditions. Insects were reared on cotton plants inside large population cages and treated from an overhead sprayer. The effects of these treatments were assessed accurately, without interfering with insects or plants, by monitoring adult numbers with an endoscope over one or more generations. Examples of single-generation and multiple-generation tests with cypermethrin are described. The apparatus is suitable for testing strategies for delaying the selection of resistance (e.g. using insecticides applied singly, alternately, or in mixture, at various application rates and frequencies), for controlling populations already resistant to insecticides, and for integrated pest management using chemical and biological control agents together.

A new genus Mesobraconoides Sarhan & Quicke is described for the species M. psolopterus (Wilkinson) comb. n. (type species) and M. truncatus (Szépligeti) comb. n. Both species have been transferred from Mesobracon. M. psolopterus is here recorded from Sierra Leone as a parasitoid of the pyralid, white rice borer, Maliarpha separatella Ragonot, widespread in the Afrotropical region. M. psolopterus is redescribed and illustrated and a key provided to separate it from M. truncatus.

A pilot field study, involving periodic augmentative release of predatory larvae of a dragonfly, Crocothemis servilia (Drury), to suppress a mosquito, Aedes aegypti (Linnaeus), was conducted during the rainy season in Yangon (Rangoon). More than 90% of pre-adult A. aegypti occurred in domestic water-storage containers. Evaluations of larval and adult numbers of A. aegypti were made half-monthly three times before, and seven times after, treatment began. Four laboratory-reared, three-week-old C. servilia larvae were placed in each major source of A. aegypti larvae immediately after the third evaluation and then monthly for three successive months. Such treatment reduced the larval population of A. aegypti to a very low level in two to three weeks and suppressed it progressively until the trial ended; the adult population was greatly reduced after about six weeks and was progressively diminished thereafter until the trial ended. The trial's success was ascribed to: the virtual confinement of pre-adult stages of the target mosquito to containers accessible to control operators; the behaviour, growth rate, survival and ready availability of the chosen species of dragonfly; and the awareness and enthusiastic participation of local householders.

The effects of endosulfan and deltamethrin, chemicals used to control Glossina morsitans Westwood (tsetse fly), were tested against Cyrtobagous salviniae Calder & Sands (Curculionidae), a biological control agent for the floating fern Salvinia molesta. The weevil was very susceptible to deltamethrin and less susceptible to endosulfan. The use of these chemicals for control of G. morsitans in Botswana, where the biological control agent is active, is discussed.