Control of cowpea insect pests has been almost entirely achieved through the use of chemicals by progressive farmers. However, the peasant farmer has traditionally tended to rely on chance and has often been unable to obtain yields that would be profitable. This paper examines the farmer's dilemma and the jrossibility of using host plant resistance (HPR) as an adjunct to other control methods in developing a sound integrated pest management of cowpea pests. The status of HPR in cowpea is reviewed with a view to identifying the areas where progress has been made with respect to the measurement and identification of resistance to formulate an effective integrated pest control program. The difficulties in achieving this are discussed in the light of our present data bank and the diversity of cowpea pests.

Thirty-five grain sorghum genotypes representing 6 variable groups (A/B-lines, R-lines, commercial varieties, germplasms, mutants and locals) were evaluated for the orientation, colonisation and oviposition responses of the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae), governing the antixenosis component of resistance. In free-choice tests, the orientation and colonisation responses of the weevil were identical among all the genotypes at 24 h, varied at 48 h, and differed widely by 72 h after adult release. High degrees of antixenosis for colonisation by the adult weevils were observed among all the genotypes except 2077A and 2219B, which suggests a predominant reaction to gustatory rather than visual or olfactory stimuli. One to five egg plugs per seed were oviposited, frequently near the endosperm close to the seed base. Greater levels of antixenosis for oviposition were noticed in 2077B, DJ 6514 and IS 11758 in free-choice tests, and 2219B, M 148–138, P 721 and Nizamabad (M) in no-choice tests. To the contrary, M 35–1, Swati and Lakadi showed greater susceptibility for oviposition. Significantly less damage to seed was observed on 2219A/B, 116B, IS 9487, IS 11758, CSV 8R(M) and Local Yellow. Although the differences in seed weight loss were not significant, this parameter was relatively lower in AKMS 14B and 2219B than in the other genotypes. This indicates the need to increase the levels of resistance among the parental A/B-lines in the development of hybrids, in order to ensure better protection from rice weevil infestation in stored sorghum.

The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier), is one of the most destructive pests of date palm in United Arab Emirates. We conducted field trials in Abu Dhabi from May 2010 to April 2011, to evaluate the effect of weekly stirring of water and dates in the RPW pheromone trap on adults captured in brown and white traps, using a randomized complete block design with four treatments and five replications. Each trap contained: (1) a dispenser of the RPW male aggregation pheromone (Ferrolure™) containing 700 mg of the active ingredient (4-methyl-5-nonanol (90%) + 4-methyl-5-nonanone (10%)) at 95% purity; (2) an ethyl acetate (EA) dispenser (Weevil Magnet™) containing 40 ml of the active ingredient of EA at 98% purity; (3) 350 g of fodder date fruits; and (4) 4 L of water. Mean adults captured in white traps was 22.5 ± 0.50 and 16.8 ± 0.41 adults/trap/month with and without stirring, respectively, while in brown traps the mean was 39.9 ± 1.31 and 28.3 ± 0.51, respectively. The overall mean of adults captured was 31.2 ± 6.21 and 22.6 ± 4.81 adults/trap/month with and without stirring, respectively. The highest number of weevils caught was in the brown traps with stirring, while the lowest was in the white traps without stirring. The results of these trials suggest the use of brown traps containing aggregation pheromone, 350 g of date fruits, EA and water. It is necessary to stir the water with dates in the traps to increase their efficacy.

Twenty-seven species of Chilo which infest graminaceous crops are listed. The effects of various cultural practices such as time of planting, plant density, field sanitation, tillage, mulching, intercropping, proper fertilizer and water management on field populations of Chilo spp. are discussed. These practices have great potential as components of IPM for resource-limited farmers in the tropics.

Rice germplasm comprising 66 lines/varieties was evaluated under field conditions for two wet seasons against a yellow stemborer, leaffolder and whitebacked planthopper (WBPH) at the vegetative and panicle initiation crop stages. Glasshouse screening of germplasm for WBPH resistance was done at the seedling stage. At the vegetative stage, over the 2 years, 18 lines/varieties showed leaffolder damage from 6.21 ± 0.33 to 9.99 ± 4.07%, while at the panicle initiation stage, six lines/varieties showed damage from 8.77 ± 1.25 to 12.25 ± 4.67%. A highly significant correlation between flag leaf width and per cent infested leaves at the vegetative (r = 0.88) and panicle initiation (r = 0.79) stages was recorded. No significant correlation was observed between plant height and leaffolder infestation at the vegetative stage; however, it was significant at the panicle initiation stage (r = 0.37). The dead heart (DH) damage at the vegetative stage over the years was less than 1% in six lines/varieties, while at the panicle initiation stage, seven lines/varieties showed whitehead (WH) damage ranging from 1.29 to 1.92%. A highly significant correlation was observed between plant height and per cent DH and WH at the vegetative (r = 0.73) and panicle initiation stages (r = 0.81). Such a relationship was not observed between leaf width and stemborer infestation at both stages. Two lines, viz. IR 59 547-235-3-3 and SPR 85 163-5-1-2-4, were resistant to the WBPH under glasshouse screening, whereas 20 lines were moderately resistant and the remaining lines were susceptible.

Grass pea Lathyrus sativus L. plays a major role in the nutrition of many poor people in Ethiopia. However, the crop suffers heavy damage by pea aphids Acyrthosiphon pisum (Hemiptera: Aphididae). To test potentially more sustainable and harmless alternatives to the commonly used insecticides, some botanicals (neem, garlic and hot pepper), soap, kerosene and the aphicide pirimicarb, were tested for their efficacy against A. pisum at Wondata village, close to the town of Bahir Dar, in northwestern Ethiopia, from 1999 to 2002. After pirimicarb, hot pepper was consistently the most effective botanical in controlling the pea aphid in terms of both pea aphid population as well as grain yield. Compared to the untreated control, there was up to 83 and 55% lower aphid population on pirimicarb- and hot pepper-treated plots in the 2000/2001 cropping season, respectively. There was also up to 93 and 54% higher grain yield on plots treated with pirimicarb and hot pepper extract, respectively. Soap was less effective, while kerosene caused phytotoxicity. Infestation levels increased with advancing maturity of the crop, rising exceptionally suddenly and dramatically near crop maturity. Combined ANOVA over years and crop growth stages indicated that aphid populations varied with years and growth stages. In 2001/2002, aphid populations were higher and grain yields were lower compared with the other years. Percentage parasitism of aphids was significantly higher on pirimicarb-treated plots (∼40%) than other treatments (<20%). Parasitism was essentially a late-season occurrence. Predator population, especially of ladybird beetles (Adonia spp.), was especially higher on hot pepper- and garlic-treated plots, and lowest on pirimicarb treated plots. Grain yield was positively correlated with level of aphid parasitism, ladybird beetle population and number of pods per plant, and strongly negatively correlated with aphid population. In conclusion, a fresh extract of hot pepper sprayed at the rate of 70 ml/4 m2 was selected for further research on rate, frequency and cost of application.

An account of the history of tick control in Uganda is given. It is presented in three phases. Phase one covers the years 1935–1970, being a period of relative stability, while phases two and three cover the periods 1971–1985, characterized by wars and political instability, and 1986 to-date, years of calm and national rehabilitation, respectively.

Mention is also made on the future strategies for the control of ticks based on new technologies and earlier experience.

At intervals of 2 months over 1 year, 64 royal cells were removed from mounds of Macrotermes michaelseni to find out whether a new royal pair was produced. In five mounds replacement reproductives were found. Young reproductives from incipient laboratory colonies were never accepted as replacements if they were introduced after the removal of the primary reproductives. One out of 10 royal pairs was accepted if the royal cell was introduced immediately after removal of the original one, and three out of 10 survived if the royal cell was introduced 1 week after the removal of the original one.

Replacement reproductives were only produced when nymphs or alates were in the nest at the time the primary reproductives were removed. It was not possible to find out at what time after the removal a new royal pair was accepted but measurements of the replacement queens showed that they can become fully physogastric within 7 months.

Preliminary studies on the life history and behaviour of the legume podborer, Maruca testulalis (Geyer), at Mbita Point on the shores of Lake Victoria have shown that most of the eggs (86%) of M. testulalis are laid on the leaf. Over 90% of such eggs laid on the leaf are oviposited on the lower leaf surface. Most adults were found to emerge between 2000 and 2300 hr. The number of eggs laid per female varied between 6 and 194, and over 72% of these were fertile. No larval or pupal diapause was observed.

Larval duration was 8–14 days and the pre-pupal stage lasted only 12–24 hr. The whole life cycle at Mbita Point was found to be about 20–57 days.

An important factor that previously discouraged detailed studies on the biology of M. testulalis is the fact that the eggs are translucent and extremely difficult to see against the background of the oviposition site. The discovery of these eggs was a major step in beginning to work on this important pest.

Various species of sandflies were collected from outdoor natural resting sites from three districts in Kenya which are endemic for kala-azar (Machakos, West Pokot and Baringo). Their blood-meals were analysed to find out host preferences. Female fed-flies were dissected for parasitological investigation. Lizards from these areas were also trapped and blood and internal organs were examined and cultured for isolation of leishmania parasites. Only the lizards obtained from West Pokot and Baringo revealed leishmania parasites in cultures. Bloodmeal analysis showed that Phlebotomus anten-natus, P. bedfordi, P. schwetzi, P. africanus, P. martini, P. affinis and P. rodhaini fed on reptiles. Additionally, promastigotes were seen and isolated from these sandfly species. The disease incidence appears to be less in areas where leishmania parasites were encountered both in lizards and the sandflies in the same locality.

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.

From 2002 to 2004, three field trials were conducted in Senegal to compare the efficacy of a new biopesticide for grasshopper control, based on the entomopathogenic fungus Metarhizium anisopliae var. acridum Driver & Milner, with mixtures of this biopesticide and cyhalothrin, a widely used pyrethroid insecticide to control the Senegalese grasshopper Oedaleus senegalensis Krauss. The aim of these trials was to obtain a knockdown effect without compromising the environmental credentials of the biopesticide too much. During the first two trials, 50 ha (2002) and 25 ha (2003) plots were treated with Metarhizium at a rate of 50 g/ha, cyhalothrin at a rate of 40 g/ha, a mixture of Metarhizium at a rate of 25 g/ha and cyhalothrin at a rate of 20 g/ha. For the third trial in 2004, several mixtures of cyhalothrin at a rate of 10 g/ha and Metarhizium at dose rates of 6.25, 12.5 and 25 g/ha were prepared. These mixtures were compared with 50 g/ha of Metarhizium, 40 g/ha of cyhalothrin and 10 g/ha of cyhalothrin on 25 ha experimental plots. The volume application rate for all trials was 1 l/ha. The Metarhizium applications resulted in a slow but long-lasting reduction of grasshopper numbers. By contrast, cyhalothrin produced a rapid reduction, but grasshopper numbers re-increased a few days after application, except in 2003, when grasshopper densities in the surrounding areas were low. The mixtures caused a similarly fast reduction in grasshopper numbers, but this lasted throughout the 3 week post-application assessment period. These trials demonstrated that adding a low dose of a pyrethroid insecticide to a slow-acting biopesticide can increase the speed of population reduction, while retaining the latter's long-lasting effect. A bonus is that the price of the combination is lower than that of each product at the recommended dose rates. Since the insecticide is added at a low dose, its environmental impact is reduced compared with the full-dose insecticide only treatment.

Males of the Triatominae, Panstrongylus megistus and Triatoma infestons, show a considerable difference concerning the time necessary for them to acquire the capacity for the first mating. P. megistus copulates from the eighth day of adult life, irrespective of whether or not it has been fed, while T. infestons copulates about 17 days after the imaginai moult and only after a blood-meal. These differences might be due to the secretory activity of T. infestons male accessory glands whose full development is reached only after two saturant blood-meals. If allatectomy is performed in male P. megistus soon after the imaginai moult, accumulation of secretion does not occur in 3 of the 4 accessory glands. Topical application of precocene II (200 μg/insect)a few days before or soon after the imaginai moult in P. megistus, halves the amount of secretion in the accessory glands.

This paper reports observations made on the sensory biology of Chilo partellus larvae and adults. The larval and adult antennae of this insect have hygro/thermosensitive sensilla equipped with receptor cells sensitive to minute changes in temperature. Inputs through those cells may partly be responsible for the light evasive and other light/temperature-dependent behaviour patterns. The grooved basiconic sensilla especially those found on the male antennae are sensitive to the female sex pheromone components of C. partellus. Host-plant odours are most likely perceived by one or two of the other antennal olfactory sensilla, namely the smooth-surfaced basiconica and coeloconica sensilla. Chilo partellus moths have a limited number of gustatory sensilla on the tarsi, ovipositor, antennae and the proboscis. Electrophysiological bioassays done on the ovipositor and tarsal sensilla are discussed. Similar tests on the larval maxillary styloconica sensilla showed that the lateral and medial sensilla differed in their sensitivity. Their taste receptor cells can detect differences between saps from susceptible and resistant host-plants.

The effects of neem seed kernel extract (NSKE), neem oil (NO) and nucleopolyhedrovirus (NPV) of the Spodoptera litura Fabricius (Lepidoptera: Noctuidae) on the mortality, feeding and development of S. litura were evaluated in the laboratory. Dose-dependent mortality was evident after NPV treatment, which also depended on larval age at treatment. Upon combining NPV with neem products, the percentage mortality was enhanced threefold even at reduced concentrations. The NSKE and NO significantly inhibited the growth and development of S. litura, and extended the duration of its larval and pupal stages. Oviposition period, adult longevity and fecundity were significantly reduced following treatment with neem products and with neem + NPV treatment. The efficiencies of conversion of ingested food (ECI) and digested food (ECD) were also significantly decreased by treatment with NSKE, NO and NPV, either alone or in combination.

A 1994 field survey of Sahelian grasshoppers and locust populations in natural vegetation, millet and rice fields in The Gambia determined the period between mid-August and early September to be the optimal time for applying oil-formulated conidia of the entomopathogenic fungus Metarhizium anisopliae var acridum to control the acridids. Locust and grasshopper cadavers were also examined for fungus infection. Metarhizium anisopliae was absent from cadavers of natural grasshopper populations, while the entomopathogenic fungus Entomophaga sp. was recovered on Hieroglyphus daganensis cadavers and the nematode Hexamermis sp. from Kraussaria angulifera, The predatory cattle egret fed on swarming adult desert locusts.

Insect species can respond adaptively to stress temperature conditions including both thermal limits and reaction norms. In this study, we considered two populations of the whitefly Bemisia tabaci (Gennadius), in which adaptive differentiation was detected for tolerance to upper thermal limits. These two populations are found in two regions of Colombia with climatic differences: the Caribbean region with high environmental temperatures and the Southwest region with lower temperature regimens. We assessed the thermal responses to a range of 1 h heat shocks (37, 39, 41, 43 and 44 °C) performed below the thermal limits for this species. Thermal responses were measured using three life-history traits involved in fitness: survival, fecundity and viability of the offspring after heat shocks. Survival or fecundity as a response to heat shocks did not differ among populations; however, there were significantly different responses for viability between populations. The Southwestern population showed higher viability responses to low heat shocks than the Caribbean population. This relationship suggests a potential trade-off, which appears to be associated with climatic regions. In addition, these results suggest that adaptation under thermal limits does not necessarily involve similar responses throughout the reaction norm. A potential ongoing evolutionary response is taking place through the thermal reaction norms for viability after the invasion by this pest in Colombia.

Some morphological characters of the rice plant were found to be associated with resistance to the African striped borer, Chilo zacconius Bleszynski. A very low, but negative correlation was recorded between percentages of bored stems and plant height. Positive correlations were recorded between percentages of bored stems and stem diameters, stem thickness, length and width of flag leaves and number of tillers per plant. High silica content in rice plants appeared to be a strong factor in resistance to the striped borer. Negative correlations were recorded between percentages of crude silica content of the plants and percentages of bored stems and number of living larvae per plant. Although each of these factors appeared to contribute to borer resistance, none by itself could be said to be the main cause of such resistance, as some varieties did not conform to some of the characters.

In leaf disc choice assays and topical application experiments, the neem (Azadirachta indica) limonoids azadirachtin, salannin, deacetylgedunin, gedunin, 17-hydroxyazadiradione and deacetylnimbin were found to be potent antifeedants and growth inhibitors to the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae). Azadirachtin was most potent in both respects. Gross dietary utilisation (efficiency of conversion of ingested food) of H. armigera was also decreased following topical application as well as after treatment in the diet. Growth inhibition in topically treated H. armigera may be primarily attributed to decreased food intake. The antifeedant and growth-inhibitory effects of the neem limonoids are discussed.