The tropical warehouse moth Ephestia cautella (Walker) is an important storage pest of maize grain. The control of this major moth pest relies heavily on the use of synthetic insecticides. We assessed the biological efficacy of a commercial neem oil (Calneem oil) against E. cautella in the laboratory, using the common grain protectant Actellic as a positive control. Contact toxicity, repellency, effects on oviposition, development and grain damage were assessed. The assays were conducted by treating 100 g of maize grains with Calneem oil concentrations of 3, 5 and 7 ml/l; and Actellic at 2 ml/l. Calneem oil significantly (P < 0.05) reduced oviposition rate, development of eggs and immature stages, and emergence rate of E. cautella progeny in maize grains. Grains treated with Calneem oil had significantly (P < 0.05) reduced grain damage in storage, and the oil had a repellency of 53–70% compared with the negative control. Calneem oil protected maize grain against damage by E. cautella for 10 weeks, compared with 20 weeks protection by Actellic. There was no resistance development to the oil for three generations of E. cautella. The insects that survived treatment with the LC90 concentration (12.2 ml/l) of the Calneem oil laid fewer eggs, and some of their progeny were deformed. Calneem oil provided a good level of protection to maize grains against infestation by E. cautella, and may therefore be a suitable substitute for Actellic.

In studies aimed at optimizing the substrate for rearing Helicoverpa armigera (Hübner) under laboratory conditions, the noctuid's oviposition behaviour was studied in the laboratory using pigeonpea leaves, muslin cloth, tissue paper and cotton wool as oviposition substrates in free-choice and no-choice tests. Egg counts revealed the moth's preference for oviposition substrate, in descending order, to be cotton wool, pigeonpea leaves, tissue paper and muslin cloth. The preference index of cotton wool was 65% higher than the least preferred substrate, muslin cloth. A total of 300 eggs per female were laid in the free-choice tests, while 200 were laid in the no-choice assays.

Citrus orchards in the Nile Delta and middle Egypt were surveyed for predacious soil mites and parasitic nematodes. There were 16 species of predacious mites and the citrus parasitic nematode, Tylenchulus semipenetrans Cobb. was recorded everywhere. In the medium-heavy soil of the Nile Delta orchards, the general predators or decomposer mites like uropodids were most common. In the light-medium soil of El-Fayoum in middle Egypt, the specialized predator mites like gamasids were most common. In localities where gamasids were common, negligible infestations of citrus parasitic nematodes were reported. Regarding Egypt as a whole, the uropodid mites Uroobovella krantzi (Zaher & Afifi) and Nenteria hypotrichus (El-Borolossy & El-Banhawy) represented about 50% of the sampled mites. The remaining mites were represented by 14 mesostigmatid species, the most common being Gamasiphis pulchellus (Berlese). At least 6% of orchards suffered injurious nematode infestations, 13% critical infestations and 22% moderate infestations, and the remaining 59% were free or with negligible infestations.

Lentil seeds infested with Callosobruchus chinensis (Linnaeus) for 12–15 days were exposed to Dinarmus basalis (Rondani) alone, Anisopteromalus calandrae (Howard) alone, or to both species, at densities of 2, 4, 8, 16 and 32 insects. Intra-specific competition and host emergence decreased with increasing parasitoid density in both D. basalis and A. calandrae, but progeny production of the parasitoids and parasitoid-induced mortality (PIM) increased with increasing parasitoid density. Dinarmus basalis was much more efficient in parasitizing C. chinensis than A. calandrae. Emergence of D. basalis and A. calandrae, and the PIM were highest at a parasitoid density of 32. Parasitoid density and a combination of parasitoids significantly (P<0.01) affected the number and progeny sex ratio of emerged parasitoids. There were significant (P<0.01) effects of inter- and intra-specific competition on host mortality. Host mortality increased with increasing parasitoid density. Parasitoid combination and parasitoid density also significantly affected PIM.

The distribution of canine leishmaniasis and figures on infection frequency in countries bordering the Mediterranean Sea are given. The clinical picture and most common laboratory findings are reviewed. Leishmania infantum is the aetiological agent of both human and canine forms of visceral leishmaniasis. The proved or suspected vectors of L. infantum are listed and mention is made of wild animals (fox, rat) as possible primary reservoirs of the parasite. Finally, the methods of investigation and control of canine leishmaniasis are discussed.

A series of experiments involving plots of sole cowpea and sorghum/cowpea intercrops were carried out, on-farm, in Minjibirr village, northern Nigeria between 1986 and 1988. The objectives were to:

(1) elucidate the relationships between sorghum/cowpea Intercropping, insect pest numbers and grain yield reductions in cowpea.

(2) examine the role of sorghum/cowpea intercropping alone or together with reduced Insecticide usage in the management of cowpea insect pests. Different cowpea varieties were grown under both cropping systems in sprayed and unsprayed plots.

The insecticides used were Sherpa Plus and/or Cymbush Super ED. Intercropping reduced the numbers of flower thrips and pod sucking bugs, but made no difference to the numbers of pod borers. Unprotected sole crop and Intercropped cowpea had yields reduced by 55 and 48% respectively, compared to sprayed subplots. The best results were obtained with three Insecticldal sprays, which increased grain yields 4.5-fold. Intercropping with two sprays produced lower, but comparable yields. Thus, it is suggested that intercropping can be used with reduced insecticide levels for the effective management of cowpea insect pests.

Different concentrations of essential oil of lemon grass, Cymbopogen citratus, were tested for their ovipositional inhibition, antifeedant activity and insecticidal properties against the lesser cotton leafworm, Spodoptera exigua. The results obtained showed that 2% concentration of oil emulsion inhibited egg laying and 0.5% concentration more than reducted by 70% the number of eggs deposited on oviposition sites. 2% concentration acts as a protective concentration against the immature stage by hindering the third instar larvae to feed on treated leaf discs. In addition, the oil emulsion was insecticidal in that percentage mortality was directly proportional to the concentration applied and to the duration of exposure. Older egg masses were more affected by treatment than the newly laid eggs. 2% concentration inhibited hatchability when sprayed on egg masses before hatching. Lemon grass oil effectively controlled S. exigua as an ovicidal and larvicidal agent.

Losses of stored seed to insects in the tropics have reached levels of major concern. Synthetic insecticides, while effective, are generally very expensive for small fanners. The efficacy of two plants, Hyptis spicigera and Cassia nigricans, used by farmers to control insect infestation in stored cowpeas was determined. The oviposition and hatching of bean weevils (Acanthoscelides obtectus), under controlled environmental conditions, were reduced following treatment with EtOH extracts (1 g plant material 1 ml EtOH) at low application rates with EC50 between 0.3 and 14 μl extract/g bean. Further field studies are proposed to determine if such natural products can be further exploited to reduce stored legume losses.

Experiments were conducted during two consecutive years (1983 and 1984) on irrigated rice, in the Southwest of Burkina Faso, in order to monitor the seasonal incidence of the rice gall midge, Orseolia oryzivora H. et G.

The damage incidence is the same whatever the date of planting within the rainy season. Attacks are low during the early growth phase of the rice plants (0 to 3% of “silver shoot”), and increase gradually to reach spectacular levels (20 to 55% of “silver shoot”) between 70 and 90 days after transplantation, after which there is decreased attack.

Parasitism is an important check on the larval population of the pest; up to 77% of parasitized larvae were observed. However, this parasitism due mainly to microhymenoptera, Platygaster diplosisae Risb. and Tetrastichus pachydiplosisae Risb., gets established late.

These results could contribute significantly in developing an IPM process on irrigated rice in Burkina Faso.

The volatility and mosquito repellency of the essential oil of Hemizygia welwitschii Rolfe (Laminaceae) and its prototype pharmaceutical formulations were examined and compared with those of a commercial mosquito repellent. At ambient temperature (28°C), neat Hemizygia oil had a volatility of 4.47±1.02 mg/cm2/ h for 15 hours, after which the rate declined. The oil evaporated at 200 μg/ cm2/ h from 10% w/w liquid paraffin solutions, and at 60 μg/ cm2/ h from soft paraffin during the first 20 hours, after which the decline in evaporation rate was generally bi-phasic. The oil demonstrated concentration-dependent repellency against the mosquito Aedes aegypti. Its liquid paraffin solutions (5% to 15% concentration) prevented up to 50% of starved mosquitoes from feeding on a blood meal for 6 hours. Lower concentrations were less effective and inhibited feeding for only 1 hour. A 15% w/w oil-in-water emulsion formulation of Hemizygia oil produced 55% feeding deterrence in the mosquitoes for 2 hours. Neither the solution nor the emulsion formulations of the oil provoked any adverse reaction on human skin.

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.

A schedule of insecticide spray combining two insecticides: Decis®(deltamethrin) and Systoate® (dimethoate) with four times of spray: 35, 45, 55 and 65 days after planting (DAP) was investigated in order to search for the most effective treatment against Maruca testulalis (Geyer) population on cowpea (Vigna unguiculata (L.) Walp). The local cowpea cultivar “Kpodjiguegue” was used to study the onset and fluctuation of M. testulalis larvae infestation on cowpea terminal shoots, flowers and pods. The trial was carried out during the 1985 early cropping season at Abomey-Cala vi. The treatments' effect on M. testulalis in the terminal shoots was not significant at the 5% level of probability because of the very low infestation of this part of the plant. In the flowers and pods, Decis® was better than Systoate® which failed in controlling this borer satisfactorily. In the unsprayed plots (i.e. control), the peak of the natural infestation occurred in the flowers towards 50 DAP and 65% of the flowers were injured. In the pods, up to 89% of infestation by M. testulalis larvae were observed 60 DAP. The lowest yield was recorded from the unprotected plots (322 kg/ha) whereas the treatment 0-Decis®Systoate®Decis® provided the highest yield (1367 kg/ha) and the highest returns.

Life table statistics on the age-specific fecundity and survival of female Spilosoma obliqua Walker reared on sunflower showed a net reproductive rate of 513.6 eggs per female, with approximate generation time of 48.2 days. Its intrinsic rate of increase (rm) was 0.1295, meaning that its population could double in 5.35 days. Spilosoma obliqua on sunflower was parasitised by Apanteles obliquae, Glyptapanteles creatonoti and Carcelia sp.

Extracts of five plants, namely Argemone mexicana, Artemisia absinthium, Cassia occidentalis, Cymbopogon citratus and Siegesbeckia orientalis were tested for their antifeedant and insecticidal effects on third-instar larvae of the cabbage webworm, Crocidolomia binotalis, which is presently one of the most important pests of cruciferous crops in Mauritius. All the five plant species investigated showed significant antifeedant properties, with A. mexicana showing the highest control potential of the five plant species studied against C. binotalis.

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.

Based on a semi-synthetic diet, a standard rearing method for the cotton bollworm, Hetiothis armigera Hübner, is described. The diet is composed of chickpea (Cicer arietinum) flour, yeast powder, sucrose, ascorbic acid, cholesterol, choiine chloride, wheat germ oil, vitamin mixture and a combination of preservatives. A plastic container for individual rearing of the cannibalistic larvae and a cage for mating of adult moths are described. After inoculation with the neonate larvae, development of the different stages was synchronouson this diet. The larval and pupal development period was 14.3 ± 1.2 and 11.7 ± 0.82 days, respectively. Females reared on this diet produced an average of 2000 eggs. Adult longevity was 22 days. The female moths retained their oviposition rhythm even after 3 years of laboratory rearing. A method for introduction of wild populations into the laboratory culture is discussed. The reliability of the technique was checked by monitoring the insects' performance for at least 25 generations.

Species diversity of animals and plants is relevant to pest management in very different ways. Plant diversity provides sources of biologically active natural products and of genes for plant resistance. Animal diversity is involved in both harmful and beneficial interactions between crops and weeds or uncultivated land and in provision of potential biological control agents. The pest management implications of changes in biological diversity therefore need to be considered at a smaller scale in the management of cropping systems and on a larger scale in development programmes and national land use planning.

Host plant resistance is an important tool in the management of the banana weevil Cosmopolites sordidus (Germar). Although ovipositing females do not discriminate between resistant and susceptible cultivars, plants of resistant cultivars have smaller larval populations and sustain less damage in the field. These observations suggest that lower damage levels observed in resistant cultivars reflect larval success. This study was carried out to evaluate laboratory screening of banana cultivars as a rapid screening method for resistance to the banana weevil by determining the influence of cultivars on weevil survivorship, development duration and adult weight. Larvae were raised on corm pieces of two susceptible, three intermediate and four resistant cultivars, resistance categories having been determined from a previous field screening trial. The developmental period was prolonged in resistant cultivars. However, cultivars had less influence on survivorship and adult weight. Moreover, the ranking of survivorship did not correlate with resistance levels observed in the field. The implications of these findings for laboratory screening of cultivars for resistance to C. sordidus are highlighted.

Pollination in the genus Ceropegia L. (Apocynaceae: Asclepiadoideae–Ceropegieae) in East Africa is discussed based on field observations and herbarium studies. All inferred or confirmed pollinators are small, mostly female dipteran flies, c. 2.5mm long, which carry pollinaria on their proboscis. Identified putative pollinator flies belong to families Milichiidae, Chloropidae and Ceratopogonidae. The most important factors for an insect to effect pollination appear to be the appropriate overall size, i.e. small size of c. 3×;3mm at most, and appropriate mouth parts, i.e. extendible probosces with suitable surfaces and adjacent pads on which a pollinarium can attach. The complex and diverse floral morphology of the tubular flowers and their disposition as well as other commonly occurring features namely, diverse interior and exterior coloration, diverse scents, secretions such as nectar and water droplets, vibratile corolla lobes and hairs, specialized hairs, interior sculpturing, sliding zones and differential lighting within the flower are important mechanisms for attracting and detaining insect pollinators.

Antheraea assamensis (Helfer, 1837) is a sericigenous insect with distinct coloration, namely green, blue, orange and yellow in their larval stages and these are multivoltine in culture. However, wild morphs with diapause are found in dense forests. In this study, the wing venation and its variation in A. assamensis were analysed using traditional as well as landmark-based morphometric methods. The venation patterns are reviewed and significant changes in veins recorded. The samples were analysed using geometric morphometric methods and other conventional statistical methods. Landmark-based data were measured among selected veins and the centroid sizes, procrustes to tangent distance of different veins were analysed. Results show significant differences in some of the veins among the intraspecies of A. assamensis. The results suggest that both visual comparison as well as a quantitative approach in A. assamensis may lead to unsound taxonomic conclusions at intraspecies level.