When marked adults of the tick Rhipicephalus appendiculatus were released into 25 × 25 cm plots in the field, their vertical distribution in the habitat was assessed after recovery, by comparing the number of ticks on the vegetation with those on the soil surface. In the hot dry season, 73% of the ticks were recovered. Of these a third were on the vegetation and two thirds at the soil surface. Out of the 67% recovered in the wet season, only 15% were found at the soil surface and the rest on the vegetation. In the cool dry season, 75% were recovered with roughly equal proportions on the vegetation and the soil surface. This suggests that only a third of the ticks would be available to be picked up by the hosts during the hot dry season. Two thirds would be available during the wet season and only half were available during the cool dry season.

This study investigated Zambian importation, distribution and use of agricultural pesticides.

Data was collected by interviews, questionnaires and direct observation at international, national, warehouse and user levels. A wide range of pesticides is available. Imports and distribution are controlled by a few multinational companies (MNC's). No government control exists on types or amounts imported, and on distribution, packaging or labelling. Safety information is virtually non-existent. Some Zambianused pesticides are under restriction in the West. The total amount used seems to be increasing. Harmful health effects have been observed. The number of involved MNC's appears to be increasing.

The largest amount of imported pesticides is used by government in large scale medical and agricultural control schemes. In agriculture, large-scale farmers use most pesticides, but small-scale farmers are now beginning to use greater amounts and more types.

Most MNC's see this latter sector as a large future market. Most farmers get pesticide information only from MNC's. By comparison, the Extension Service is inadequate. Consequently, the authors suggest that the following are needed: A broad based Zambian advisory committee on pesticides; government legislation of importation, distribution, packaging, labelling and safety; and Extension Service expansion.

Seasonal incidence of the sorghum earhead bug, Calocoris angustatus Lethierry, was studied by sowing the crop once in 10 days, throughout the year during 1978 and 1979, as well as by sowing it at fortnightly intervals from early “kharif” to late “rabi” during 1979. The bug was found throughout the year except for a few weeks during March, April and May. The milky stage of the earhead was the most preferred stage compared to pre-flowering, a third flowering, flowering and ripening stages. The adults dominated during pre-flowering and a third flowering stages whereas nymphs dominated during milky and ripening stages. The computed seasonal indices were higher during August (230), September (222), October (224) and January (215) which coincided with blooming and milky stage of sorghum in general fields. Correlation studies between the bug population at the milky stage and maximum temperature indicated negative and significant (r = -0.2967) relationship, and positive and significant (r = +0.2727) relationship with relative humidity. Low incidence of bugs was observed on the crop sown during June.

Moths of the genus Anaphae (Lepidoptera, Thaumetopoeidae) cause skin eruptions in Africa, conveniently called ‘papillonite’ or Lepidopterism. The hairs or ‘flechettes’ of adult female moths may be responsible for this disease. The morphology of the urticant apparatus of the moths, Anaphae venata and A. panda, has been studied with the scanning electron microscope. In these two species, the ‘flechettes’ are implanted in individual sockets. Although their morphology is identical, their size is different in A. venata and A. panda. Morphological differences with other urticating species of the genus Hylesia (Saturniidae), are discussed.

Twelve cultivares were grown along with released high yielding hybrid CSH-1 (susceptible to stem-borer) to investigate their relative resistance to stem-borer at three locations. Results obtained have established that the 12 cultivars possess moderate levels of resistance to stem-borer. The damage suffered by them was significantly lower than CSH-1. Further, four cultivars viz. E601, E 602, E 603 and E 604 suffered less damage.

The stability of the resistance was worked out by following the model of Eberhart and Russell (1966) [Crop Sci. 6, 36–40]. The means of various cultivars were calculated and regression coefficients (bi) were tested against unity to locate most adaptable cultivar for borer damage. The cultivar × environment interactions for leaf injury and stem tunnelling (two parameters used for assessing stem-borer damage) were significant and in most of the cases were due to linear response of different cultivars. Cultivar E 601 proved to be most promising and stable for resistance to stem-borer.

This paper considers the status of pests and pesticides in Mauritius, including pesticide legislation and flow.

Climatic factors, namely altitude, temperature and rainfall, influence the spatial and seasonal distribution and population dynamics of economically important pests as well as their hosts (crops and livestock). The case histories of a few selected pests (leaf miner, fruit flies, stable flies), their control measures as well as research efforts in this connection are reviewed.

An appraisal is also made on some aspects of pesticide legislation along with the distribution pattern of pesticides, in relation to pesticide management. The setting up of a recent Pesticides Management Advisory Committee is regarded as a move in the right direction to safeguard pesticide misuse and abuse. Food crop production is at the expense of huge pesticides input. A series of recommendations are made with a view to improving pesticide practices in the country.

Efficacy of olfactory attractants incorporated in biconical traps to enhance the catch size of Glossina pallidipes Austen was investigated. Preliminary studies considered the effectiveness of a mixture of waste products from buffalo (Syncerus caffer) and that of warthog (Phacochoerus aethiopicus). The results were compared with the known tsetse olfactory attractants, carbon dioxide and acetone. When the waste product components from buffalo were used in the traps separately, buffalo urine was found to be by far the most effective. This component, used in its natural state inside the trap, increased G. pallidipes catches almost 10-fold when compared with the control catch.

Upwind flight has been elicited in tsetse, Glossina morsitans exposed to host odour and to active components of host odour (carbon dioxide, acetone and 1-octen-3-ol) in a wind tunnel. With the exception of octenol the odours also produce marked kinetic effects in G. morsitans, G. austeni, G. pallidipes and G. palpalis. Threshold concentrations for G. morsitans are in the region of 0.2% for ox odour, 0.01% for carbon dioxide and 400 μgl−1 for acetone.

Batches of engorged Rhipicephalus appendiculatus ticks (females, nymphs and larvae) were placed in gauze-covered vials in the field at monthly intervals and left to complete development. The ticks were placed in open areas and tree shaded areas; the latter being consistently cooler.

The duration of development varied seasonally and was inversely related to environmental temperature. The mean time to oviposition ranged from 5 days during the hot dry season to 25 days during the cool dry season. There was a high larval mortality during the larval to nymphal moult. However, the available data shows that the mean time to larval–nymphal moult ranged from less than 2 weeks during the hot dry season to 7 weeks in the cool season. The mean time to nymphal–adult moult ranged from less than 3 weeks in the hot season to over 13 weeks in the cool dry season. Egg hatching ranged between 3 weeks in the hot dry season and 15 weeks in the cool dry season.

The serpentine leaf-miner Liriomyza trifolii is a new proliferous and polyphagous agricultural pest in Mauritius, attacking crops, ornamentals and weeds. Urgent chemical control measures had to be developed in order to save total crop loss, in particular potato, tomato, haricot beans, crucifers and onions. This insect is resistant to most insecticides. In view of formulating an integrated management programme, this paper reports on some aspects of practical importance concerning the biology and ecology of the leaf-miner, the incidence of damage, and the possibility of its control by natural plant products such as extracts of neem (Azadirachta indica). Steam distillates of neem leaves seriously affect larvae and pupae upon treatment by contact at as low a dose as 0.3% of the extract. Field treatments of onion plantations with aqueous neem extracts (0.5%) gave good protection to the crop. The current control measures are briefly considered.

The importance of maximum rates of insemination in female tsetse is emphasized in relation to their low rate of reproduction and to the possibility that density dependent regulation of tsetse populations may not be as rigorous as in many oviparous insects. Observations on the mating behaviour of tsetse are described and its regulation by sex pheromones which serve to identify females of the species is discussed. Laboratory and field experiments have shown that the sexual activity of G. m. morsitans males can be manipulated by presentation of synthetic sex pheromone on suitable decoys in the laboratory and in the field. Males that respond to decoys in the field are in the same nutritional state as others which are attracted to the models upon which the decoys are placed and are presumably seeking food. There is no reason to believe that sexual activity is restricted to a particular section of the population, and given a choice, it is proposed that mating is preferable to feeding in terms of gene survival for the individual male. The durations of copulatory responses are dose dependent and there is some evidence that they are inversely proportional to the frequency of encounters with decoys and hence to the density of flies. Techniques for the reduction of tsetse populations using sex pheromones in conjunction with suitable decoys and chemosterilants are being developed. The availability of pheromones in large quantities will permit their testing as sexual confusants among males and may lead to interspecific matings where more than one species occupies the same habitat.

Greenhouse studies were conducted by artificially infesting potted rice plants with first instar larvae of Maliarpha separatella and Sesamia botanephaga Tarns and Bowden at two stages of plant growth, namely: early tillering stage and at the booting stage. Early infestation by M. separatella resulted in reduction of plant height and the number of filled grains. At the booting stage, the number of filled grains and their weight were higher in uninfested plants. Infestation by S. botanephaga at both stages of plant growth mainly affected the number of productive tillers. Grain weight was unaffected. Field studies on individual hills gave erratic results and there were instances when hills containing tillers bored by M. separatella produced higher yields than unattacked hills.

On exposure of maize grains mixed with groundnut oil at a dose of 20 ml/kg, 100% mortality of the rice weevil, Sitophilus oryzae (L.) was observed within 24 hr and 100% at 10 and 5 ml/kg in 2 and 3 days.

Egg-laying and progeny development in the rice weevils were completely prevented at groundnut oil doses other than 1 ml/kg at which the number of eggs laid and progeny developed were 27 and 38% of those in the oil-free control during the same period. When maize treated with oil at 10–20 ml/kg was reinfested after 19 weeks with fresh adult rice weevils, less than 42% of them had died. The total number of progeny that emerged on week 23 from the two higher doses of oil was 38% of that emerging from the control.

Groudnut oil does not affect the viability of maize grains and damage after 25 weeks. Viability of maize grains was only 6–13% after oil treatment at 10–20 ml/kg compared to 100% in the untreated control.

The termite Macrotermes subhyalinus (Rambur) builds large earthen mounds of many different types, two of which are described in detail here. As far as is known at present, the two types occur in different areas. The main difference is in the ventilation system. In one, the Bissel type, there are many holes connected up inside the mound in such a way that external air is drawn through the passages and cools the interior of the mound. The other, the Marigat type, has only one large opening raised to a considerable height above the ground so that air is drawn out at the top, and drawn in from the surrounding soil through underground foraging passages.

Seed yield loss was independent of the eggs laid on and damage to the buds, flowers and pods by the larvae of the borer, Adisura atkinsoni Moore at the 0.05% level. Loss in seed yield was dependent on seed damage. Seed damage, thus can be used to precisely locate a borer resistant Lablab niger cultivar, but in an already pre-selected germplasm.

The paper is a report of an on-going investigation into the quality and quantity of pesticides imported into Uganda and how candidate pesticides for importation are selected. Also under investigation is the method of distribution of the pesticides from importers to farmers and their management at the farm.

The investigation reveals that owing to improper documentation by the importers, it is at present virtually impossible to establish the quantities of pesticide imports. The study also shows that the present system does not allow for proper supervision of the quality of pesticides used in the country. It highlights the need for revision of the laws and setting up of an infrastructure to facilitate this supervision.

The study shows that although most farmers would be conscious of the toxicity of these pesticides, they are largely unaware of the possible long-term effects of poor handling of the pesticides, both to themselves and to the environment.

Whole body tick collections, carried out at 6-day intervals for 2 months at Nisheishiba, showed significant differences in tick counts between three breeds of cattle. Crossbred (Bos taurus × B. indicus) cows carried 4.5 times more ticks (mean tick count 70.5 ± 84.8) than the B. indicus Kenana (mean tick count 16.7 ± 24.4) and Butana cows (mean tick count 15.0 ± 18.4). In all cases, the SD's were larger than the means reflecting the usual wide variability in tick numbers between individuals. Significant differences also existed in the degree of engorgement achieved by female Hyalomma anatolicum anatolicum ticks on different breeds of cattle. The weight of detaching fully engorged females feeding on Kenana and crossbred cattle was 374.8 mg and 422.0 mg respectively. This was reflected in the amounts of eggs laid by the females which were 191.3 mg for the Kenana-fed ticks and 261.1 mg for those from the crossbreds. The resulting larval challenge from the crossbred-fed ticks was 36.5% greater than from the ticks fed on Kenana cattle.

Seven species of mosquitoes oviposited in open and bored bamboo traps at a site in Peradeniya, Sri Lanka, the most prevalent being Aedes albopictus, Aedes novalbopictus and Armigeres subalbatus. These three species preferred to lay in open than in bored traps. Aedes albopictus and Ar. subalbatus preferred to lay at ground level but Ae. novalbopictus showed no preference between ground level, 3.5 and 7.0 m height. A comparison of two collection series, one with traps in fixed positions and the other with traps interchanged randomly with respect to the positions, showed that individual trap attractiveness is a factor that can have a marked influence on the overall oviposition trends in Ae. albopictus and Ar. subalbatus.

A study of oviposition with respect to height above the water level showed that in Ae. albopictus and Ar. subalbatus, more than 75% of the eggs were laid within about 16 mm of the waterline. However, there was a markedly greater dispersion of eggs in Ae. albopictus, indicating more vertical movement during oviposition in this species than in Ar. subalbatus.

A study on the biology of the sorghum midge, Contarinia sorghicola Coq., and the damage and crop loss it causes was carried out under field conditions during the main planting season at Mbita, in Western Kenya. The developmental period from egg to adult ranged from 17 to 34 days with a mean of 23 days. On average, 3.2 adult midges emerged from each damaged spikelet. Adult emergence was bimodal, with a major morning peak and minor late afternoon peak. A predator, Diaperasticus erythrocephala Olivier (Dermaptera: Forficulidae), was found preying on newly emerged adults. The level of damage varied among 38 sorghum lines tested, with the size of the panicle (r = 0.73; P < 0.05) and the number of days to 50% flowering (r = 0.49; P < 0.001) influencing the level. The level of damage for the sorghum variety Serena ranged from 1.8 to 97.7% and grain yield from 22.3 to 0.9 kg/50 m2, respectively for plantings during the months of March–June. The relationship between damage and crop loss was almost perfect (r = 0.998; P < 0.001).

This study presents an interpretation of the way the Punjabi farmers in a village of the arid Sind perceive the pest hazard and the methods of management that they employ to deal with this situation. It is found that farmers do recognize the seriousness of the problem which consequently leads them to employ traditional as well as pesticide treatment of their crops. But because of financial handicap and other factors, they do not use pesticide regularly or in adequate quantity. As a result the control of pests remains ineffective.