Dengue vector control programmes are mainly focused on insecticide fogging/space spraying to control adult Aedes mosquito vector populations. Due to the diurnal habit of the vectors, spraying is routinely conducted during the day when many other insect species are also active. This study reports the simultaneous effect of fogging on non-target insects by direct counting of knockdown in the insect population. Eight fogging treatments were conducted in two sites in Kurunegala District of Sri Lanka. Pesguard insecticide was sprayed in each treatment for 8 minutes according to the standard methodology and the ‘knockdown insects’ were collected on randomly spread polyethythene sheets (10 m2). A total of 3884 insects (24.3 insects per treatment per m2) belonging to 12 orders were collected and 12.44% of them recovered during a 24-hr recovery period. Diptera was the most affected insect order (36%) followed by Collembola (30%) and Thysanoptera (17%). Out of the 31 mosquitoes (<1%) collected, only two (<0.1%) belonged to the genus Aedes. Body length of 93% of the affected insects ranged from 0.35 mm to 1.8 mm. Positive controls using the WHO standard cage bioassays with the mosquito Ae. albopictus (n = 417) and the stingless bee Trigona iridipennis (n = 122) showed 100% initial knockdown, and 83.5% mosquito and 93.5% bee mortalities after the recovery period. The study shows that insecticide fogging does have a severe effect on non-target insects such as pollinators; therefore, fogging operations should be done in a controlled manner and indiscriminate fogging should be avoided.

The tea mosquito bug Helopeltis theivora (Waterhouse) is an important economic pest of tea in India. The development of resistance in H. theivora populations obtained from a conventional plantation and an organic plantation was studied in the laboratory for five generations, and associated changes in life cycle traits were assessed. Selection using sub-lethal concentrations of endosulphan resulted in a 4.4-fold increase in insecticide resistance ratio from the F1 to the F5 generation in the H. theivora population from the conventional plantation. By the F5 generation, nymphal duration was higher and fecundity was lower in the endosulphan-selected strain than in the non-selected strain from a conventional plantation and the susceptible strain from an organic plantation. These findings have practical implications for insecticide resistance management of this important sucking pest of tea.

The effect of infestation of lepidopteran borers on yield of maize was assessed at three locations in the forest and forest/savanna transition zones of Cameroon, during the first and second season of 1992. Maize was treated once or twice with the systemic carbofuran at different developmental stages. The species encountered were the stem-boring noctuids Busseola fusca and Sesamia calamistis, which oviposit on and attack pre-tasseling stages of maize; the stem-boring pyralid Eldana saccharina, which attacks plants at and after tasseling; and two ear borers, namely the pyralid Mussidia nigrivenella and the tortricid Cryptophlebia leucotreta. Generally, carbofuran reduced infestations by B. fusca and S. calamistis but had little or no effect on species attacking the plant's later stages. Thus early treatments with granules into the whorl were more efficient than late treatments as a side dressing, and a second late treatment had little effect. During the first season, late-attacking species were predominant and grain yield losses of 17–44 % were found in one location only. During the second season, species attacking young plants (mainly B. fusca) became predominant in all three locations and yield losses of 30 to 41 % were found in two of the three locations. The percentage of ears with damage was especially high during the second season. As green maize is an important source of cash income in the area and damaged ears cannot be sold, the economic loss was likely considerable.

Several Arthropod pests have been collected and identified on coffee, Coffea arabica. L. in Ethiopia, but only a few are economically important. Based on the plant part the pests feed on, they can be categorized as flower and flower bud feeders, leaf feeders, berry (fruit) feeders, twig and branch feeders borers and stem (trunk) borers.

Antestia, Antestiopsis intricata (Ghesquiere) Carayon and blotch leafminer, Leucoptera Caffeina (Washbourn) are the two most important pests feeding mainly on young fruits and leaves respectively.

Studies made regarding biology, feeding habits, population dynamics and natural enemies (parasitoids and predators) of Antestia are described. The buildup of this insect starts in March and reaches its peak around May/June although slight variations have been observed in various coffee growing areas. Young berries are the most preferred part of the plant. Antestia eggs 45–50% are attacked mainly by three species of parasistoids of which Asolcus suranus (Nixon) was found to be the most important.

In this study, the effect of exposing entomopathogenic bacteria isolated from macerated termite cadavers to varying intensities of a magnetic field for different periods of time on their pathogenic potential was examined; pathogenicity tests were carried out for each of the bacterial species. Two of the bacteria, Bacillus subtilis (Ehrenberg) Cohn and Serratia marcescens Bizio, were able to induce morbid effects on termites and both were re-isolated from the resulting cadavers. Reinfection using different concentrations of both bacteria was carried out on termites to determine the minimum lethal concentration required for pathogenicity. Bacillus subtilis was able to degenerate the termites at concentration values of 108 colony-forming units (cfu)/ml and S. marcescens at 107cfu/ml. Both bacteria were then exposed to magnetic fields of different intensities for different periods of time, after which they were used for reinfection of healthy termites. Post-infection study after the exposure of termites to magnetic field-treated bacterial cells revealed no reduction in the entomopathogenic potency of S. marcescens. As the extensive use of chemicals to control insect pests has been found to have detrimental effects on people and the environment, there is a pressing need to discover and develop new entomopathogens to control these insects biologically. Therefore, bacteria discovered in this study to have entomopathogenic potency against termites may be further studied and formulated into either powdery forms or suspensions to be applied to infested wood or wood products.

The present study was part of a larger surveillance effort to identify the determinants of African honey bee health, and, particularly, to detect honey bee pathogens across Kenya, where 160 colonies were examined from 32 apiaries (five colonies/apiary). From each colony, 20 individual foragers, nurse bees, worker pupae, and drone pupae were sampled separately. These were organized as 30 foragers, 32 nurse bees, 28 worker pupae, and 10 drone pupae pools. Nucleic acid was extracted from the pooled homogenates and tested using a panel of 18 different (RT-)PCR methods targeted at detecting Paenibacillus larvae, Melissococcus plutonius, Ascophaera apis, Aspergillus spp., Nosema ceranae, N. apis, Deformed wing virus (DWV), Varroa destructor virus 1 (VDV 1), Acute bee paralysis virus (ABPV), Sacbrood virus (SBV), Israeli acute paralysis virus (IAPV), Black queen cell virus (BQCV), Chronic bee paralysis virus (CBPV), and Kashmir bee virus. All amplified bands were sequenced and compared to the GenBank database. VDV 1 was the most abundant virus at 50% prevalence in the 100 bee pools. It was closely followed by DWV at 44%. The others were BQCV (36%), SBV (14%), IAPV (9%), ABPV (8%), and N. ceranae (5%). The pathogens co-existed within apiaries. VDV 1 was present in 66% of the apiaries, DWV in 69%, BQCV in 69%, SBV in 28%, IAPV in 22%, ABPV in 19%, and N. ceranae in 13%. The study concludes that these pathogens should be incorporated in honey bee disease surveillance activities in the region.

Integration of the sterile insect technique (SIT) into the area-wide management of the peach fruit fly Bactrocera zonata (Saunders) is a promising alternative to the localized use of chemical control tactics. Implementation of the SIT requires adequate numbers of sterile male insects that are produced in large mass-rearing facilities. The present study was carried out to improve the rearing methods of the peach fruit fly so as to contribute to the development of effective mass-rearing protocols. Commercially available papaya, mango, peach and guava juices were found to be equally effective as oviposition stimulants. Moreover, with respect to the fecundity and fertility of flies, water was found to be as effective as the tested fruit juices. During the first 3 weeks, 90% of the total eggs produced were collected from adult oviposition cages holding 50,000 flies. A larval diet composed of sugarcane bagasse, ground maize, sugarcane sugar, waste brewer's yeast, wheat bran, benzoic acid, nipagin and water resulted in the following values for the quality control parameters: egg hatch 85%, pupal recovery >67%, pupal weight >4.2 g, pupation >95%, adult emergence >89%, and fliers >65%. Adult emergence and flight ability were similar for pupae placed in sand and vermiculite as the pupation medium.

The antibiotic effects of 12 different cotton genotypes on Bemisia tabaci (Gennadius) were studied during June–July and August–September 2003, with the objective to determine the biological parameters which are important to study the mechanism of antibiosis and to identify the genotypes in which antibiosis is operating. The detailed biology of whitefly, i.e. developmental period, survival, fecundity, longevity and sex ratio were studied under ‘no choice’ conditions, by confining the whiteflies in leaf cages. The study revealed that incubation period, nymphal developmental time, total developmental time, nymphal survival, total survival, fecundity and female longevity are the most important biological parameters for detecting the presence of antibiosis in resistant cotton genotypes against whiteflies. On the other hand, pupal period and survival, male longevity and sex ratio do not seem to play important roles in antibiosis. The combined effect of these parameters indicated that Gossypium arboreum genotype PA 183 was the most resistant while Bt 6304, TX Maroon 2–78 and F846 were the most susceptible ones. Other genotypes with moderate resistance include Supriya and LD 694.

Some factors affecting oviposition by Plodia interpunctella (Hubner) were studied under various controlled conditions in the laboratory. The effect of temperature, relative humidity, light and mating on oviposition were investigated.

Temperatures of 25 and 30°C were optimal for oviposition. The best condition was 30°C and 80% r.h. at which an average of 315.3 eggs were laid per female during its lifetime. The least favourable temperatures investigated were 15 and 35°C. Relative humidity did not have significant effect on the number of eggs laid at 15 and 25°C but at higher temperatures of 30 and 35°C, high r.h. increased the number of eggs laid by individual moths.

Light regimes of 12 hr light and 12hr darkness (LD) and 24 hr darkness (DD) were more favourable than 24 hr light (LL) for oviposition.

Virgin females laid fewer eggs than mated females while prolonged virginity reduced the number of eggs laid and caused resorption of immature oocytes and retention of ripe eggs in the ovaries.

Food losses caused by insects during postharvest storage are of paramount economic importance worldwide, especially in Africa. Laboratory bioassays were conducted in stored grains to determine the toxicity of powders of Eugenia aromatica and Moringa oleifera alone or combined with enhanced diatomaceous earth (Probe-A® DE, 89.0% SiO2 and 5% silica aerogel) to adult Sitophilus granarius, Tribolium castaneum and Acanthoscelides obtectus. Adult mortality was observed up to 7 days, while progeny production was recorded at 6–10 weeks. LD50 and LT50 values for adult test insects exposed to plant powders and DE, showed that A. obtectus was the most susceptible towards the botanicals (LD50 0.179% and 0.088% wt/wt for E. aromatica and M. oleifera, respectively), followed by S. granarius. Tribolium castaneum was most tolerant (LD50 1.42% wt/wt and 1.40% wt/wt for E. aromatica and M. oleifera, respectively). The combined mixture of plant powders and DE controlled the beetles faster compared to the plant powders alone. LT50 ranged from 55.7 h to 62.5 h for T. castaneum exposed to 1.0% M. oleifera and 1.0% DE, and 0.5% E. aromatica and 1.0% DE, respectively. Botanicals caused significant reduction of F1 adults compared to the control. Combined action of botanical insecticides with DE as a grain protectant in an integrated pest management approach is discussed.

Iris yellow spot virus (IYSV) vectored by Thrips tabaci threatens profitable onion production in eastern Africa. Host plant resistance is considered to be the first line of defence against insect-transmitted virus diseases. Hence, information on resistance to IYSV and T. tabaci among common onion cultivars in Kenya is crucial for the development of integrated pest management strategies. This study evaluated the resistance to thrips and IYSV among widely grown onion cultivars in Kenya, viz. Red Pinoy, Red Creole, Bombay Red, Green Bunching and Texas Grano, over two growing seasons. Straw-coloured, diamond-shaped necrotic lesions typical of IYSV infection were observed 2 weeks after transplantation. Observations on thrips numbers per plant, IYSV disease incidence and severity, and virus intensity were undertaken to assess the resistance. Varieties differed significantly with respect to both IYSV disease incidence and thrips numbers per plant from fourth week to physiological maturity. Red Pinoy, Green Bunching and Red Creole were highly susceptible to the virus and thrips, while Texas Grano and Bombay Red were moderately resistant. There were significant differences among the varieties with regard to IYSV intensity, with the highest and the least virus intensity positively correlated with disease severity being recorded in Red Pinoy and Texas Grano, respectively. Among the varieties, Texas Grano produced the highest yield in both seasons, while Red Pinoy produced the least. Hence, Texas Grano and Bombay Red could be recommended as moderately resistant cultivars to thrips and IYSV to be grown in Kenya for markets where pungency is not preferred and preferred, respectively. Regions with high levels of thrips population and IYSV infestation are not suitable for the cultivation of Red Pinoy.

Conidial suspensions of four isolates each of Beauveria bassiana and Metarhizium anisopliae were evaluated in the laboratory for their virulence to adult Ootheca mutabilis. All the isolates tested were pathogenic to the beetle, but to varying degrees. Three of them, B. bassiana CPD 3 and CPD 10 and M. anisopliae CPD 6 were superior to all other isolates in terms of mortality induced on adult beetle, LT50 and LC50, with B. bassiana CPD 3 having the lowest LC50 value. In feeding assays; consumption by beetles treated with B. bassiana CPD 3 was significantly reduced within 2 days treatment (DAT) and the trend continued until 7 DAT, when all the beetles died. The antifeedant effects of the pathogen on O. mutabilis could partly offset its slow speed of kill, and might play an important role in field control.

This study was conducted in the Knuckles Forest Region in central Sri Lanka, and investigated how termite species richness, abundance and functional group diversity vary in different montane forest types and identified the likely causes of this pattern. Termite diversity declined with increased elevation, with upper montane forests recording a single endemic species, Postelectrotermes militaris Desneux. Transect sampling in lower montane forests yielded 26 species, with a higher number from dry forests (22 species) than from wet forests (15 species). Species specificity also was high in dry forests (11 species) compared with wet forests (four species). Termite abundance did not show a distinct trend in dry and wet forests. Live-wood termites were present only in upper montane and high-altitude lower montane dry forests. Wet forests had a higher relative abundance (78%) but not species richness (40%) of soil and soil–wood interface feeders. In dry forests, both species richness (82%) and abundance (88%) of fungus-growing wood feeders were higher. The study suggests that key drivers of the species distribution pattern are low temperature and differing forest floor conditions. In the upper montane forest floor where earthworms dominate, wet soil and damp, woody litter riddled with beetles are not favourable for termites. In lower montane wet forests, moist, thick decomposing leaf litter and in dry forests, drier, relatively undecomposed leaf litter with many dry sticks and branches support species with specific food habits.

The potential egg production and egg viability of the potato tuber moth, Phthorimaea operculella (Zell.) was significantly lowered when moths of either sex were exposed in 250 ml glass jars to vapours of orange peel oil emanating from 160 μ oil. Oviposition and egg hatching was totally inhibited when female moths of both sexes were exposed to 220 μl of the oil.

Frankliniella schultzei Trybom is a polyphagous pest and vector of tospoviruses worldwide. It occurs in dark and pale colour forms that are morphologically similar but differ in vector competency and geographic spread. In Kenya and other tropical regions, mixed populations of both colour forms are observed in similar habitats, so are considered as one species. To ascertain the taxonomic status of the two colour forms, they were characterized using morphological, molecular, biological and ecological approaches. Morphological characterization revealed differences between the colour forms on eight features and they separated into distinct clusters through principal component analysis. Restriction fragment length polymorphism of the internal transcribed spacer region (ITS-RFLP) analysis revealed differences between the two colour forms and was confirmed by differences in ITS2 sequences. Virgin pale females had female offspring (thelytoky), while virgin dark females had male offspring (arrhenotoky). Interbreeding of dark males with pale females resulted in pale females, indicating absence of interbreeding between the two colour forms. Laboratory colonies of pale forms lacked males and further analysis of F. schultzei males from Ipomoea setosa flowers in the field indicated the presence of dark males and the absence of pale males. Field surveys in Kenya indicated differences in distribution and host plant preferences among the colour forms. Lack of interbreeding, distinct host preferences and distribution, and morphological and molecular differences indicate that the two colour forms of F. schultzei could be different species. The results highlight the need for combining morphological, biological, molecular and ecological characteristics for resolving taxonomic status of closely related insects.

The anthocorid bug Orius albidipennis Reuter is a generalist predator that feeds on the whitefly Bemisia tabaci Gennadius and the strawberry spider mite Tetranychus turkestani Ugarov & Nikolski in greenhouse crops. There are no previous studies on the potential efficacy of the predatory bug against these pests on greenhouse crops. We report on the efficacy and the prey preference of the predator to control these pests on different host plants under laboratory conditions. In a laboratory experiment, we estimated the predation rates of O. albidipennis at different densities of each prey after 24 h on cucumber and sweet pepper leaves. Predation rates of the predatory bug to T. turkestani and B. tabaci were significantly higher on sweet pepper leaf than on cucumber leaf. We studied the effect of plant species on prey preference and switching of O. albidipennis to B. tabaci and T. turkestani using Manly's α index values and Murdoch's no-switch line, respectively. Our results show that O. albidipennis prefers T. turkestani to B. tabaci on both host plants but its preference for T. turkestani on sweet pepper is significantly greater than on cucumber. Moreover, on sweet pepper, preference values are completely fitted by Murdoch's no-switch line. The findings suggest that morphological defence traits of plants, such as hairy leaves of cucumber, may effectively change prey preference and reduce predation success of O. albidipennis.

Sources of information on the biology and ecology of Chilo species are reviewed on a world-wide basis, with emphasis on the major pest species which are stem borers of rice, maize, sugar-cane, sorghum and other cereal crops and grasses. Information on geographical distribution, host plants, general biology, ecology and population dynamics is summarized for the main species, especially for C. partellus (Swinhoe), C. suppressalis (Walker), C. infuscatellus (Snellen), C. sacchariphagus (Bojer), C. auricilius (Dudgeon), C. zacconius Bleszynski and C. agamemnon Bleszynski. Other species are also noted, including C. diffusilineus (de Joannis), C. panici Wang and Sung, C. terrenellus Pagenstecher, C. polychrysus (Meyrick), C. plejadellus Zincken, C. niponella (Thunberg) and C. orichalcociliellus (Strand). Requirements for additional and better organized information are identified.

A survey involving more than 129 farmers was carried out in 1998 and 1999 in Ouémé, Benin, to investigate the importance of pests and diseases as constraints to cowpea (Vigna unguiculata (L.) Walp.) production. Results indicated that in the Ouémé valley Sclerotium rolfsii Sacc. and Aphis craccivora Koch are specific concerns. Weeds such as justicia anselliana (Nees) T. Anders, Ipomoea aquatica Forsskal and Commelina erecta L. were also reported as being troublesome. On the Ouémé plateau Imperata cylindrica L. Beauv. was reported to be a major weed. Callosobruchus maculatus Fab. and Bruchidius atrolineatus Fab. may cause up to 100% loss within a few months in storage. Birds and rodents were also reported. In certain areas on the plateau, farmers have developed pest control methods based on indigenous knowledge. In the valley the population density of Eichhornia crassipes (Mart) Solms. during flooding is used by farmers to predict aphid infestation. A number of plant species used to protect cowpea were reported. In Gbékandji village, natural enemies such as Rhabdepyris sp., Evania sp., and Chelonus sp., were observed. They were rare in the valley, where farmers rely on chemical control. Farmers reported alternative hosts of cowpea pests from the families Fabaceae (eight species), Mimosaceae (two species), Ceasalpiniaceae (five species), Capparidaceae (two species) and Pontederiaceae (one species). Based on the hierarchy of constraints, sustainable integrated pest management technologies are being developed with farmers using a participatory approach.

Aulacophora foveicollis Lucas causes economic losses to creeping cucumber [Solena amplexicaulis (Lam.) Gandhi] growers in India and Bangladesh because adults feed on the leaves and flowers causing death of the plant. The insect is a generalist herbivore as it also causes damage to pumpkin, bottle gourd, sponge-gourd and gac fruit production by feeding on leaves and flowers of these plants. At present, insects are controlled with insecticides, which are harmful to human health and the environment. We studied the behavioural responses of adult A. foveicollis to flower surface waxes and synthetic compounds mimicking flower surface waxes to determine their potential for monitoring this pest. The gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID) analyses of S. amplexicaulis flower (50 g) surface waxes indicated presence of 17.9 and 3.1 mg alkanes and free fatty acids, respectively. Seventeen n-alkanes from n-C15 to n-C34 and 16 free fatty acids from C10:0 to C22:0 were detected in the flower surface waxes. Heptacosane was predominant among n-alkanes representing 2748.1 µg; whereas, pentadecanoic acid was the major fatty acid accounting for 466.6 µg. Aulacophora foveicollis were attracted to the flower surface waxes at concentrations of 4 to 8 μg/ml, as demonstrated by a Y-tube olfactometer bioassay. Using a dose response bioassay, the insect was shown to be attracted to individual synthetic pentadecane, heptacosane, nonacosane, undecanoic acid and nonadecanoic acid at 0.70, 0.70, 1.20, 1.60 and 1.40 µg/ml, respectively. The insect displayed highest attraction to a synthetic mixture of 0.70, 1.23, 0.77, 0.84, 0.94 and 0.74 µg/ml of pentadecane, heptacosane, nonacosane, undecanoic acid, lauric acid and nonadecanoic acid, respectively, and hence, this combination might be used for insect pest management such as in baited traps.

The traditional values of caterpillars to the Bisa people of northern Zambia were assessed through a questionnaire survey involving 104 households from 24 villages. Information validation was by Participatory Rural Appraisal, Focus Group Discussions, caterpillar collection and identification. Caterpillars of eight Saturniidae moth species are valued very highly by the Bisa. Six of these were collected and identified from the miombo woodlands of the study area. The harvesting of Gynanisa maja (Klug), Gonimbrasia belina (Westwood), Cirina forda (Westwood), Imbrasia epimethea (Drury), I. rubra (Bouvier) and Imbrasia sp.3 caterpillars by local people, provides an alternative source of dietary animal protein and is associated with several cultural and spiritual processes and beliefs which bind the people together as one tribe. Edible caterpillars are bartered and sold at markets, enabling the local people to gain access to goods and services that normally are out of their reach. An individual collector processed 11.5 kg of sun-dried edible caterpillars worth Zambian Kwacha (ZK) 172,600 (US$ 52) during the caterpillar-harvesting period in 1999, while a household averaging six members processed 69.1 kg caterpillars worth ZK 1,036,098 (US$ 309). The income generated from sales of edible caterpillars far outstripped that generated from the sale of agricultural produce. Estimates of household incomes for 1999, an edible-caterpillar bumper harvest year, and the Bisa traditional edible-caterpillar management system are discussed.