In the Chitwan valley, Nepal, Chilo partellus preferred maize and sorghum over rice, teosinte, finger millet and sugar-cane. Infestation on young maize plants produced “dead hearts” and on older plants reduced growth and sometimes prevented cob formation. The yield reduction in some maize cultivars reached 60% and stem infestation levels reached 98%. Borers produced “dead hearts” in young and “whiteheads” in older rice plants.

The egg, larval and pupal periods from April through September lasted 4–5, 16–41 and 4–8 days, respectively. A complete generation took 28–48 days under summer field conditions and 192–233 days from October to May. Of the one egg, four larval and two pupal parasitoids, all hymenopterans, which were reared from C. partellus, the two most important were Trichogramma chilonis (70% egg parasitism) and Apanteles flavipes (30% larval parasitism).

The functional response of fourth instars, adult males and females of the sevenspotted lady beetle, Coccinella septempunctata Linnaeus (Coleoptera: Coccinellidae), was studied at different densities of aphid, Lipaphis erysimi (Kaltenbach) (Homoptera: Aphididae). The maximum prey consumption was recorded for fourth instars at the highest prey density (800) and the minimum for the male lady beetle at the lowest prey density (25). The prey consumption by the predatory stages of the lady beetle was directly and the percent prey consumption inversely proportional to prey density. Prey handling time decreased with increasing prey density. Regression analysis showed a linear relationship between the log number of prey exposed for predation and prey consumed. The predatory efficiency of the predator stages was directly proportional to prey density, indicating a Holling Type II functional response.

A systematic account of the lepidopterous cereal stemborers in Africa is presented. The identification and distribution of the economically important species is discussed. Systematic problems are pointed out.

Genetic variation of resistance and tolerance to stem-borer, Chilo partellus, was studied in three sorghum crosses. Parents, F1 and F2 progenies were evaluated for per cent foliar damage and stem tunnelling as a measure of resistance or susceptibility. The parental cultivars involved in the crosses represented a fairly distinct range of character expression for plant height, foliar damage, stem tunnelling, stem lodging and grain yield. Means, degrees of dominance in F1 and inbreeding depression in F2 suggested that susceptibility was dominant over resistance in crosses susceptible x resistant and susceptible × tolerant, while resistance was dominant over susceptibility in the cross tolerant × resistant. The variation patterns of foliar damage and stem tunnelling in parents, F1 and F2 progenies suggested that they are different and are independently inherited. Both resistance and tolerance mechanisms are operating in sorghum resistance to stem-borers and these mechanisms are independently inherited. Estimates of heritability (broad-sense), genetic coefficient of variation and expected genetic advance, indicated that the cross Serena (tolerant) x IS 2146 (resistant) provides maximum chances of selecting resistant and tolerant plants in the segregating populations. Recurrent selection (population breeding) is suggested to improve the level of stem-borer resistance and tolerance and yield in sorghum.

Phytosanitary measures are a major barrier to trade in papaya. We assessed the infestation of tephritid fruit flies on different stages of maturity of papaya, to determine its non-host stage of maturity, for market access. Papaya fruits were collected from Kilifi and Embu counties, Kenya from March 2013 to December 2014, to assess the level of infestation by fruit flies according to the degree of fruit ripening. In all locations, no fruit fly infestation was recorded on papaya when fruits were at the 0, 25 and 50% yellow fruit ripening stage. Bactrocera dorsalis (Hendel) was, however, observed attacking fruits when papaya fruits were at 75 and 100% all yellow (fully ripe fruit ripening stage) with infestations of 0.19−0.51 B. dorsalis/kg fruit and 0.24−1.24 B. dorsalis/kg fruit, respectively, in all locations. Field cage exposure of B. dorsalis to fruits of five papaya cultivars—‘Papino’, ‘Neo Essence’, ‘Sunrise Solo’, ‘Tainung No. 1’ and ‘Tainung No. 2’ in Manica Province, Mozambique—showed that B. dorsalis did not infest fruits at 0, 25 and 50% yellow ripening stages at the densities of 50 and 100 flies per cage. However, at 75% yellow ripening stage, up to 13.1 pupae/kg of fruits was recorded at a density of 150 flies per cage in Tainung No. 1, and infestation ranged from 4.5 to 136 pupae/kg fruits at 100% yellow ripening stage across all the cultivars and infestation densities. Laboratory evaluation of volatiles emanating from freshly crushed papaya pulp of four cultivars: ‘Sunrise Solo’, ‘Red Lady’, ‘Papayi’ and ‘Apoyo’ on egg viability of B. dorsalis showed that at 0, 25 and 50% yellow, egg hatchability was inhibited, suggesting that semiochemical compounds present in green tissues of papaya prevent egg development, although this effect was variable across the four cultivars and ripening stages. Export papaya is harvested at less than 40% yellow ripening stage. Our results, therefore, suggest that quarantine treatment for fruits at this ripening stage is inconsequential, as B. dorsalis does not infest papaya fruits at this stage; thus, authorities should permit entry of these papaya cultivars of less than 40% yellow ripening stage to quarantine-sensitive markets.

Glossina pallidipes, a widely but discontinuously distributed African savanna species, is one of the economically important tsetse flies because it is a vector of trypanosomiasis, a lethal disease of cattle and other domestic animals. DNA sequences of ribosomal (r16S2, 249 bp) and cytochrome oxidase I (COI, 421 bp) concatenated mitochondrial genes were analysed in 23 geographically diverse samples of G. pallidipes from Ethiopia, Kenya, Tanzania, Zambia and Zimbabwe. Among 873 flies, we detected 181 composite haplotypes and found that their spatial diversities and frequency distributions were heterogeneous. Haplotype and nucleotide diversities were greatest in Ethiopia and least in southern Africa. We observed little haplotype and nucleotide diversity among regions, and detected severely limited maternal gene flow among the sampled populations (ΦST= 0.42). Tests for demographic stability and analysis of mismatch distributions revealed regionally contrasting demographic histories. The Ethiopian populations were phylogenetically the oldest and genetically the most diverse, and exhibited successive waves of contraction and expansion. The southern African populations were phylogenetically the youngest and genetically the least diverse, and showed only a single, recent expansion. Likely ecological correlates of historical tsetse fly demography include population suppression trials in East Africa and recurring rinderpest epizootics in southern Africa, beginning in the late nineteenth century that reduced host mammalian populations.

Pesticide spray thresholds, as a component of Integrated Pest Management, must be integrated with the world of smallscale farmers if they are to be useful to them. The capacity and desire to spray have specific features of significance for threshold control. Threshold use may be encouraged by maximising the divisibility of pesticide technology. Farmers' perception of thresholds, often subjective and personal, may be enhanced by information learned from outsiders, as complementing, rather than supplanting, their existing knowledge and experience.

Three 9-acridone alkaloids, melicopicine, tecleanthine and 6-methoxy tecleanthine were isolated from the bark of Teclea trichocarpa. Melicopicine and tecleanthine exhibited mild antifeedant activity against the African armyworm, Spodoptera exempta. All the three alkaloids showed antimicrobial activity against the fungus, Cladosporium cucumerinum and the bacterium, Bacillus subtilis.

We studied the distribution of wild Mediterranean fruit flies, Ceratias capitata (Diptera: Tephritidae) in different environments of trimedlure-baited Jackson traps during high fall season populations in Southern Egypt. We found that 98% of females attracted to within aim radius of standard trimedlure (TML)-baited Jackson traps remained on the surrounding foliage without approaching the trap. Also about 30 % of males aggregated there, calling and competing for matings with approaching females. The closest mating occurred 25 cm from a standard trap. The nearest lek formation away from a trap was observed at a distance of 2 m on the same trap tree. The highest captures of males were recorded in the morning after male calling on the foliage reached its daily peak. Jackson traps baited with both protein hydrolyzate and TML on cotton wicks caught as many males, but significantly more females than traps with TML only.

The effects of temperature on the development of Orius albidipennis (Reuter) (Hemiptera: Anthocoridae), reared on its prey, Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), were studied in the laboratory. Nymphal mortality was 87, 48 and 38 % at 20, 25 and 30 °C, respectively. With the exception of first-instar nymphs, percentage mortality was lowest at 25 °C. Pre-oviposition period and longevity decreased with an increase in temperature. Mean daily and total fecundity were 2.1 and 76.4 respectively at 25 CC. The mean developmental period from oviposition to adult eclosion was 27.7, 14.1 and 10.9 days at 20, 25 and 30 °C respectively. There was a linear relationship between temperature and developmental rate (1/day) of O. albidipennis. Lower thermal thresholds were 13.8, 13.5, 12.7, 15.0, 13.8 and 12.5 °C for eggs and nymphal stages 1 to 5, respectively, with the corresponding average degree-day requirement of 46.9, 42.6, 33.3, 29.2, 26.1 and 51.4 days, respectively. The implications of these results for biological control of thrips are discussed.

There were significant differences in the level of susceptibility among the 12 varieties which were screened for resistance to A. lycopersici Pronounced tolerance to leaf damage was recorded on varieties Early Stone Improved and Beauty. Oxheart and Bonny Best both of which had comparatively lower mite densities were highly susceptible. Flower bud formation was not significantly affected by the mite damage. However, the number of dead flowers and flower buds on infested plants was significantly more than on protected ones.

Russetting of young fruits due to mite damage differed significantly among the varieties tested, and was positively correlated with moisture content of young fruits. The least and most affected varieties were Beauty and Red Cloud respectively. The percentage yield loss was highest on Hybrid Beefmaster and Oxheart and lowest on Roma and Money Maker.

Two mark-release-recapture experiments were carried out on a female population of A. africanus in the Zika Forest, in Uganda, to estimate density, survival rates, dispersal range and duration of the gonotrophic cycle. Marking was achieved using powdered fluorescent pigments and wet paint. In the first experiment, unfed A. africanus female mosquitoes were marked and released. A high overall recapture rate of 17.6% was recorded consisting mainly of first recaptures (up to 85.6%). The highest recapture rate was recorded during the first 4 days after release. Using Jolly's Stochastic Model, daily population estimates ranged from 1386 to 8406 during the first 7 days of release. The daily average population estimated over the first 10 days was 3591. Using the Simple Lincoln Index, population estimates ranged from 1104 mosquitoes to 16,320 with an average daily estimate of 3706. Of interest was the fact that the average daily population estimates using the two methods were not statistically significant. The 24-hr survival rate averaged over 9 days was 0.9228. Dispersal was rather random, and appeared to be of a limited range with an average distance of 50 m. In the second experiment, which involved marking only fully engorged mosquitoes, an overall recapture rate of 7.1% was recorded, with an average daily survival rate of 0.8209 averaged over the first 4 days. The pattern of recaptures indicated a gonotrophic cycle of 5–6 days with a small proportion of mosquitoes seeking secondary feeds during the first 48 hr. It was generally observed that marking and handling did not have any marked effect on mosquitoes during the first 8 days.

Coelomomyces indicus was reisolated from six larvae of Anopheles gambiae in Uganda. A crustacean copepod Cyclops sp. was found to be infected (63%). This indicated that the copepod could be an intermediate host for the fungus. All the four instars were highly susceptible to C. indicus but fourth instar Aedes aegypti was fairly susceptible (94.2%), while second instar An. gambiae (100%) and second instar C. fatigans (100%) were the most susceptible.

Laboratory tests were conducted to compare reproductive capacity and longevity of An. gambiae, C. fatigans and Ae. aegypti when infections of C. indicus were induced in each of the different larval instars. Infections of C. indicus sharply reduced the reproductive capacity and longevity of An. gambiae, C. fatigans and Ae. aegypti, regardless of the instar that were exposed and became infected. The reductions were highest when first and second instars were exposed. The tests indicated that introduction of C. indicus into laboratory populations of An. gambiae, C. fatigans and Ae. aegypti consisting of mixed larval instars, could significantly reduce the number and fertility of eggs and thus result in an average reduction of about 65.4% for An. gambiae, about 46.7% for C. fatigans and 58.7% for Ae. aegypti of the F1 progeny from those females that became infected. The importance of these results in biological control is discussed.

The effect of mixed cropping cow pea with maize on general predators' abundance and their influence on population density of Megalurothrips sjostedti (Trybom) on cowpeas was investigated in the field and in exclusion cages. Populations of predatory ladybird beetles, Orius sp. and earwigs (Dermaptera) were not significantly influenced by mixed cropping. The density of spiders, however, was significantly higher in the cowpea sole crop than in the cowpea/maize mixture. The population density of M. sjostedti was significantly less in the cowpea/maize mixture than in cowpea sole crop, both inside cages, where predators were excluded, and outside. We concluded that this reduced population density was not the result of enhanced predators’ population in the mixture.

The ovipositional orientation of an aphidophagous ladybird beetle, Propylea dissecta (Mulsant) (Coleoptera: Coccinellidae) in terms of geo- and photo-taxis, colour and texture of substrates was studied. The beetle exhibited a high preference for negatively geotactic substrates for oviposition. There was no clear preference for positively or negatively phototactic substrates. When studied in combination, it was observed that substrates that were negatively geotactic were preferred over other substrates regardless of the phototaxis. Red was highly preferred over the other 5 colours tested, and plastic was the substrate of choice for P. dissecta oviposition.

Argasid ticks have been induced to feed successfully through different types of artificial membranes but this technique has not been easily applicable on ixodid ticks. In order to get hard ticks to feed artificially, two major approaches have been employed: Feeding on a diet through artificial membranes; and feeding from diet-filled capillary tubes placed over the tick's mouthparts. In both cases the ixodid ticks could not be fed to repletion. This paper gives a brief account about artificial feeding of ticks in general and the techniques used to obtain successful feeding of an ixodid tick Rhipicephalus appendiculatus through a modified Baudruche membrane.

The life history of Amblyseius fustis (Pritchard and Baker) was studied in the laboratory at a fluctuating temperature and relative humidity ranging from 24.4 to 28.0°C and 55.5 to 75.6%, respectively. The developmental stages consist of egg, larva, protonymph, deutonymph and adult. The life cycle, from egg to adult of both male and female was about 8 days, while longevity was about 19.2 days. Mated female laid an average of 18.8 eggs. There was no significant difference in the longevity and fecundity of predators fed on different life stages of the host. The proportion of male to female in the progeny of mated females was 1:4.

A. fustis has a shorter developmental period and lives longer than its prey, but the latter is more fecund (26.9 eggs/♀) and has a higher proportion of females in its progeny (1:4.8). The shorter developmental period and the longer life span of the predator are likely to offset the higher fecundity of the prey.

The vectors of Leishmania major were investigated in Marigat, Baringo District, Kenya, a focus of both visceral and dermal leishmaniases. These studies resulted in the discovery of the resting sites of Phlebotomus duboscqi, a known vector of L. major, and of alternate principal resting sites of Phlebotomus martini, a known vector of visceral leishmaniasis. Furthermore, Sergentomyia ingrami was incriminated as a possible vector of L. major among susceptible rodents inside burrows. Trapping methods which have resulted in the discovery of the resting sites of these phlebotomine sandflies are presented in this paper.

Establishment and maintenance of a laboratory colony of Phlebotomus argentines are described which presently is in the nineteenth generation. Larvae were reared in modified plastic vials and were fed with a newly prepared food. Emerged flies were kept in adult holding cages at 50–90% r.h. and 25–26°C and provided with 30% sucrose solution. The average development time (egg to adult) of each generation in the laboratory was about 32 days at 28–31°C. Adult females were fed blood on hamsters, humans and white mice. Observations were made on mating behaviour, host preference, oviposition, effect of temperature, etc.

The efficacy of neem kernel cake powder water extract (NKCP-WE) and Dipel 2x (Bacillus thuringiensis var. kurstaki) in controlling the diamondback moth (DBM), Plutella xylostella Linn. (Lepidoptera: Yponomeutidae), on cabbage was evaluated in screenhouse experiments. All concentrations of NKCP-WE tested were larvicidal and plants treated with 25 and 50 g/l NKCP-WE retained larvicidal activity for up to 2 weeks after application. The efficacy of 25 and 50 g/1 NKCP-WE and 0.5 g/1 Dipel 2x was compared by observing DBM development on the treated plants and yields of those plants. Dipel 2x-treated plants had less DBM larval infestation than the neem-treated plants but the latter treatment gave better yield. The implications of these observations are discussed.