The coconut palm is an important plantation crop in India, where it is cultivated on 1.796 million hectares. The rhinoceros beetle, Oryctes rhinoceros L. (Coleoptera: Scarabaeidae) is a serious pest of coconut throughout India and southeast Asia, causing an estimated 10% yield loss in the crop. Successful biological control of this pest could be achieved using the non-occluded Oryctes virus (syn. Baculovirus oryctes or Oryctes baculovirus). This review provides an account of this microbial agent, its biology, effects and impact, production and maintenance and alternative hosts, particularly in the context of the Indian situation. It also proposes future areas for investigation on the virus, in order to achieve its commercial viability and more widespread use.

The incidence and distribution of the sorghum head bug, Eurystylus oldi Poppius (Heteroptera: Miridae), and other panicle pests of sorghum in research stations and farmers' fields in West and Central Africa (WCA) were assessed from 1985 to 1994. Maximum head bug abundance was observed during the dough stage. Head bug abundance was greater on improved cultivars, while the local guineense sorghums with long glumes were less susceptible, both at the research stations and the farmers' fields. Grain damage was moderate to severe, although farmers were mostly unaware of this insect and its damage potential, because it remains hidden inside the panicle. Sorghum midge (Stenodiplosis sorghicola Coq.) damage was very high on farmer's fields in Burkina Faso, Niger, and Nigeria. The shootfly Atherigona soccata Rond., stemborer Busseola fusca Fuller, grasshoppers, spittle bug Locris rubens Erichson, Campylomma spp., Creontiades pallidus Ramb., Agonoscelis spp., head caterpillars Helicoverpa armigera Hub., Pyroderces simplex Wlsm. and Eublemma gayneri Roths., were other insect pests damaging sorghum in the areas surveyed. It is proposed that future efforts in sorghum improvement for WCA should focus on developing cultivars with resistance to sorghum head bugs.

The habitat preferences and activity patterns of Glossina swynnertoni Austen were studied using Siamese traps, electrified screens and vehicle patrols in Aitong, southwestern Kenya in three habitats: large thicket, wooded grassland and an Acacia community. Except in the Acacia community, G. swynnertoni occurred in association with Glossina pallidipes Austen. Apparent density varied significantly among the three habitats, being highest in the Acacia community, intermediate in wooded grassland and lowest in large thickets. Density also varied seasonally, with higher densities occurring in the rainy season than in the dry season in all three areas. Vehicle patrol was a more effective and rapid method for sampling G. swynnertoni than either Siamese traps or electrified screens. However, vehicle patrol catches were strongly biased in favour of males (4:1). Diurnal activity in the Acacia community was unimodal for both sexes, with peaks of activity occurring at 1100–1200 h for males and at 1400–1500 h for females. Both sexes remained active in the afternoon but activity declined rapidly towards dusk (1700–1800 h).

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.

Neozygites floridana (Weiser & Muma) Remaudière & Keller and Hirsutella thompsonii Fisher are important fungal pathogens of mites on cassava in Benin. Bioassays were conducted to evaluate the influence of four concentrations (50, 100, 200 and 500 ppm) of a water-dispersible formulation (Gaucho 70 WS) of imidacloprid on the conidial germination of these two fungi. Imidacloprid significantly reduced the germination of primary conidia and formation of infective capilliconidia in N. floridana. In contrast, imidacloprid concentrations of 100 ppm and above increased conidial germination in H. thompsonii. Another bioassay was conducted to evaluate possible synergism between imidacloprid and H. thompsonii in the mortality of the cassava green mite, Mononychellus tanajoa (Bondar). Hirsutella thompsonii alone and in combination with imidacloprid both killed around 95% of the mites after five days. In contrast, the mortality of mites treated with imidacloprid alone was close to that of untreated mites, which was around 30% on the fifth day after treatment.

The defoliating beetle Mesoplatys ochroptera Stål (Coleoptera: Chrysomelidae) has become a serious pest of the tropical legume Sesbania sesban (L.) Merrill in agroforestry systems in eastern and southern African countries. In this study, 32 accessions of Sesbania spp. collected from eastern and southern Africa were screened for resistance to M. ochroptera at Msekera, Zambia. Two mechanisms of resistance—antixenosis and antibiosis—were indicated in the different accessions. Accessions of Sesbania bispinosa, S. leptocarpa and S. macrantha were found to be more preferred by the insect compared to S. sesban and S. rostrata accessions. Preference of accessions was negatively correlated with leaf-hair density and positively correlated with the number of leaves per seedling and plant height. Under the conditions of eastern Zambia, some accessions of S. sesban from Kenya, Malawi and Ethiopia were found to be comparable to the Zambian accessions in survival, growth and biomass production. Four accessions of S. sesban—Kakamega (ex Kibwezi) and Kisii 2 from Kenya, Zwai 090 from Ethiopia and Rumphi from Malawi—appeared to compensate well for M. ochroptera damage.

1,8-cineole, one of the components of the essential oil of Artemisia annwa, was evaluated for repellency and toxicity against three stored product coleopterans—Callosobruchiis maculatus F. (Coleoptera: Bruchidae), Rhyzopertha dominica F. (Coleoptera: Bostrychidae) and Sitopliilus oryzae L. (Coleoptera: Curculionidae). It was found to be moderately repellent to all three species, with a mean repellency in the range of 65–74% at the highest dose tested (4.0 μl/ml) within 1h. A contact toxicity assay revealed that direct topical application was more effective than using impregnated filter paper. The compound was more effective as a fumigant and gave 93–100% mortality against all the three pest species at the dose of 1.0 μl/l air under empty jar conditions as compared to treatment of jars filled with grain (11–26% mortality). The lethal dose and lethal concentration required to kill 50% of the beetles (LD50 and LC50) respectively varied.with the toxicity assay method. LD50 values of 0.03, 0.04 and 0.04 μl/insect against C. maculatus, R. dominica and S. oryzae respectively were found in the topical application assay while the LC50 in the fumigant assay was 0.28, 0.33 and 0.46 μl/l against C. maculatus, R. dominica and S. oryzae respectively.

Résumé: —L'un des composés de l'huile essentielle d'Artemisia annua, le 1,8-cineole, a été évalué pour sa répulsion et sa toxicité vis à vis de trois coléoptères des denrées stockées, Callosobrnchus maculatus F. (Coleoptera: Bruchidae), Rhyzoperta dominica F. (Coleoptera: Bostrychidae) et Sitopliilus orizae L. (Coleoptera: Curculionidae). Il s'est avéré être modérément répulsif pour les 3 espèces, avec une répulsion moyenne de 65–74% à la plus forte dose testée (4.0 ml/ml) pendant 1 heure. Un essai de toxicité de contact indique qu'une application locale directe est plus efficace que l'utilisation d'un papier filtre imprégné. Le composé est plus efficace en fumigation et provoque 93–100% de mortalité chez les trois espèces de ravageurs à la dose de 1.0 ml/l d'air dans un pot vide par rapport à un pot rempli de grains (11–26% de mortalité). La dose létale et la concentration létale requises pour tuer 50% des scarabées (LD50 et LC50 respectivement) varient avec le type d'essai de toxicité. Des valeurs de LD50 de 0.03, 0.04 et 0.04 ml/insecte pour C. maculatus, R. dominica et S. oryzae respectivement ont été trouvées dans l'essai avec une application locale alors que la LC50 dans l'essai de fumigation était respectivement de 0.28, 0.33 et 0.46ml/l pour C. maculatus, R. dominica et S. oryzae.

The developmental, oviposition, and mortality rates for the polyphagous earwig Diaperasticus eryihrocephala Olivier feeding on pollen and Ephestia kuehniella Zeller eggs were measured at constant temperatures of 18, 25 and 32 °C. The developmental period for D. erythrocephala required 533 degree-days (DD) above a threshold of 6.7 °C. Egg and larval development rates increased with increasing temperature, with the shortest developmental period being recorded at 32 °C. However, egg and larval mortality and larval malformation rates were significantly higher at 32 than at 25 and 18 °C. Over a period of 60 days, females laid an average of 26.5 eggs at 25 °C and none at 18 °C. Based on the results obtained, it is concluded that of the three temperatures, 25 °C is the most suitable for the laboratory mass rearing of D. erythrocephala.

Fresh plasma from the African eland, Taurotragus oryx, contains a factor that inhibits the transformation of bloodstream-form Trypanosma brucei brucei into procyclic (midgut) forms. Heating of the plasma at 42, 50 and 60 °C for 30 min resulted in a 20, 38 and 40% loss of inhibitor activity respectively, whereas only negligible loss occurred below 42 °C. Similarly, one and four freeze-thawing cycles resulted in 32 and 60% loss of activity respectively. Inactivation of the inhibitor activity, which occurred rapidly during storage (for example, 80% loss after 7 days at -20 °C) could not be stopped by the addition of various protease inhibitors or lyophilisation of the plasma. Treatment of plasma with pronase (1 mg/ml for 2 h) completely abrogated the inhibitor activity, whereas trypsinisation had only a partial effect. Ammonium sulphate fractionation of fresh plasma showed that the inhibitor was insoluble above 50% salt. When the plasma was fractionated by anion-exchange chromatography, the inhibitory activity was recovered in the bound fractions. Efforts to purify the inhibitor were unsuccessful due to the rapid loss of activity under all conditions tested. It is concluded that the low capacity of eland blood to support transformation of bloodstream trypanosomes is due to an inhibitor present in the plasma fraction.

The distribution of the types of sensillae in the adult red palm weevil, Rhynchophorus ferrugineus (Oliv.) (Coleoptera: Curculionidae), was studied using scanning electron microscopy. Five types of sensillae can be identified on the antenna, with no apparent differences between sexes. These are: multiporous peg sensillae, sensillae trichoïdea (I and II); sensillae basiconica (type I, II and III) and sensillae styloconica. The distal segment of the maxillary palp bears 22 sensillae basiconica in the female, 13 in the male.The upper and lower incisor cusps of the mandibles of the male are relatively longer and more rounded, with an angle of 45° or more where the inner margins of the cusps meet. In the female, the upper and lower cusps are slightly shorter, with an angle of about 45°. In the buccal cavity of females, groups of finger-like sensillae basiconica of various length and shape project toward the centre of the oral opening. In the male, multiporous peg sensillae are found. Sensillae trichoidea are present on the ventral and dorsal sides of the first, second and third tarsal segments distally. These are much denser on the male than the female. On the terminal (9th) abdominal segment of the ovipositor, sensillae are distributed on the dorsal plate, medial plate, ventral plate and anal leaflets (paired). Sensillae of four types occur on the anal leaflets.