In Cameroon, the demand for hive products is growing. Honey and pollen yields are low in this country, partly because of the poor knowledge of the apicultural value of the flora. To determine the apicultural value of Combretum nigricans Lepr. ex Guill. & Perr., Erythrina sigmoidea Hua, Lannea kerstingii Engl. & K. Krause and Vernonia amygdalina Delile, Apis mellifera adansonii Latreille activity was observed on the flowers of these plants in Ngaoundéré from December 2001 to May 2002 and from December 2002 to May 2003. The flowers of each plant species were prospected for at least 4 days per month, between 07.00 and 18.00 h, for recording the nectar and/or pollen foraging behaviour of A. m. adansonii workers. Results show that A. m. adansonii harvested the nectar of each plant species. In addition, L. kerstingii and V. amygdalina were visited for pollen. The greatest number of workers foraging simultaneously on a plant varied from 26 (E. sigmoidea) to 4200 (V. amygdalina). Apis mellifera adansonii workers that visited flowers of a given plant species once generally remained with these nectar and/or pollen sources throughout the observation period. Thus C. nigricans, E. sigmoidea, L. kerstingii and V. amygdalina could be cultivated and protected to increase honey production; L. kerstingii and V. amygdalina could enable beekeepers to increase their pollen production as a hive product. During foraging, A. m. adansonii workers increased the pollination possibilities of each plant species.

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.

A new plant-feeding species of braconid wasp Allorhogas minimus Centrella & Shaw is described from Heredia Province in Costa Rica. The new species is diagnosed and compared with other species in the genus. This is the first record of an Allorhogas species from fruit galls on Miconia longifolia.

The activity of a crude enzyme preparation extracted from hepatopancreas in the digestive tract of the giant cricket Brachytrupes membranaceus (Drury) was assayed for amylase and α-glucosidase. Amylase- and α-glucosidase-specific activities were estimated to be 3.31 and 13.02 UI/mg, respectively. The zymogram analysis of the crude enzymatic extract showed the existence of two isoforms of amylase. For α-glucosidase, the zymogram analysis showed one form only. Both the amylolytic activities exhibited optimum pH at 6.6 and 7.0, respectively, for amylase and α-glucosidase. As for optimum temperature, values were estimated at 55 and 40 °C for amylase and α-glucosidase activities, respectively. Amylase activity was found to be stable at pH 6.6–7.6 and temperatures up to 55 °C. The corresponding values for α-glucosidase were pH 6–7 and up to 40 °C. Amylolytic enzymes of B.membranaceus were activated by Ca2+ and Ba2+ and inhibited by chemical agents such as ethylenediaminetetraacetic acid, 4-chloromercuribenzoic acid and dithionitrobenzoic acid. The analysis of hydrolytic products after soluble starch hydrolysis by the enzyme preparation from the digestive tract of B. membranaceus by thin layer chromatography revealed that glucose and maltose were the major products. The present study showed that these amylolytic enzymes play a fundamental role in energy production for this insect.

Homidium bromide is a broad-spectrum anti-microbial trypanocide likely to be encountered as a violative residue in blood collected from abattoirs destined for feeding laboratory-reared tsetse colonies. We investigated its effects on longevity of laboratory-reared Glossina morsitans morsitans Westwood. Four steers were intra-muscularly administered with 1 mg homidium bromide/kg of body weight and blood was aseptically collected from them between 15 and 30 min post-administration. This blood was defibrinated, analysed for homidium levels, screened for bacterial contamination, frozen and warmed to 37°C before feeding to tsetse flies. Teneral male (100) and female (220) G. m. morsitans flies were fed on homidium-treated diet, and control flies (99 males and 187 females) on untreated blood diet and their survival monitored for 163 days. Homidium, at 266.15 ng/ml blood diet, significantly (P < 0.05) improved fly survival. We concluded that homidium bromide has a beneficial effect on tsetse, probably attributable to its antimicrobial activity against unfavourable microbes mediated by the drug, and could be used as a tsetse diet additive.

Following observations by a service engineer (mid-2007), 12 of the hundreds of installed packaged plant (PP) sewage systems were producing relatively large numbers of Culex quinquefasciatus (Say) and a variety of filth flies in George Town, Grand Cayman. Due to the vector potential of C. quinquefasciatus in the Caribbean, we explored the efficacy of industry-standard insecticides against C. quinquefasciatus. Since PP systems contain an organic biofilm on the water surface, we devised a modified technique for collecting immatures and for the application of insecticides. We treated functioning and non-functioning PP systems with Bacillus sphaericus (VectoLex® WDG), Bacillus thuringiensis var. israelensis (Bti; VectoBac® CG), temephos (Abate® 4-E), monomolecular film or ethyoxylated alcohol surfactant (Agnique® MMF) and (S)-methoprene (Altosid® Pro-G). B. thuringiensis var. israelensis gave control for 35 and 48 days for functioning and non-functioning systems, respectively, with less control from B. sphaericus (high label rate) (c. 25 and 35 days) and temephos (suggested label rate) (c. 27 and 33 days). B. sphaericus (low label rate), monomolecular film and (S)-methoprene gave limited control of immatures (i.e. no mortality detected after 24 h). Treatment options for PP systems are discussed with regard to economics, operational feasibility, and within the context of integrated mosquito management. Functioning systems were recolonized at a faster rate than those that were not functioning, but the level of infestation in the non-functioning systems was considerably greater.

We surveyed three locations in West Africa, two in northern Nigeria and one in southern Niger, for the presence of wild alternative hosts of the legume pod borer (LPB) Maruca vitrata Fabricius, which could serve as natural unstructured refugia for transgenic Bacillusthuringiensis (Bt)-cowpea. We surveyed a total of 67 sites in proximity to cowpea fields in the Sudan Savannah (Kano, Nigeria), the Northern Guinea Savannah (Zaria, Nigeria) and the Sahel Savannah (Maradi, Niger) ecological zones. The results indicate that alternative host plants for LPB are scarce or absent during the cowpea-growing season in these areas.

In the present study, immediate and trans-generational effects of parental diets (i.e. abundant and scarce) were investigated in a ladybird beetle Anegleis cardoni (Weise). Prey scarcity prolonged pre-oviposition period and reduced fecundity and egg viability. Reduced survival and developmental rate of progeny was recorded under prey-scarce conditions. The progeny of parents reared under prey-scarce conditions developed more slowly than that of those reared under prey-abundant conditions, regardless of the progeny diets. This study indicates the existence of parental diet effects on progeny survival and developmental attributes.

The study sought to confirm reports by farmers and agricultural extension personnel of Prostephanus truncatus (Horn) attacking harvested maize in Mashonaland West and Mashonaland Central provinces of Zimbabwe and to map out, using pheromone trap catch data, the distribution of the pest in the country. A survey of 296 respondents confirmed the presence of P. truncatus in five districts of the provinces. Some respondents reported that the first few sightings of the pest were in 2005 or earlier, while the majority mentioned the 2006/2007 storage season. The map showed a more concentrated distribution of P. truncatus in the northern part of the country moving further inland towards the central and eastern parts of Zimbabwe, indicating possible spread of the pest from the neighbouring countries Zambia and Mozambique. The results of the study indicate legitimate concerns over food security with respect to stored maize grain and seed. The occurrence of P. truncatus in the country has serious implications on training of extension agents and packaging of extension messages that need to be disseminated to the farming community to reduce the impact of the pest. This is the first evidence-based and official documented report of P. truncatus occurrence in Zimbabwe.

During 2007, phytophagous thrips on soybean (Glycine max Merr.) were collected, and differentiated according to sex, genus and species. Scouting for thrips was carried out on leaves and flowers in two consecutive plantings in Adjuntas, Isabela and Juana Diaz, Puerto Rico. A total of nine genera were found, of which eight species were identified. These included Frankliniella cephalica, Frankliniella gossypiana, Frankliniella insularis, Frankliniella schultzei, Caliothrips phaseoli, Neohydatothrips inversus, Rhamphothrips sp., Scirtothrips dorsalis and Thrips palmi. The last species was the most common in the three locations. However, F. schultzei was the most abundant species in Juana Diaz.

Malaise traps are often used in trapping Muscidae flies for studying species dynamics, but there has been no specific evaluation of the influence of the duration of exposure of the traps in the field and their normal wear and tear on the relative richness and abundance of individuals of different species caught. To evaluate the possible influence of these factors, we installed Malaise traps at Arroio Grande and Pelotas, Rio Grande do Sul, which are located inside the Campos Sulinos biome in Brazil. In Arroio Grande, new and 18-month-old Malaise traps were installed between March and May, 2004, and in Pelotas, new and 12-month-old traps were installed between April and June of the same year. At each site, the traps were installed 10 m apart, and collections of trapped insects were made at intervals of 7 days. The age of the traps significantly influenced both abundance and richness of the Muscidae trapped, probably because of the changing colour profile at the top of the traps. From these results, we concluded that the use of Malaise traps in the field for long periods to evaluate richness and abundance of muscid flies in biodiversity studies needs re-evaluation.

The effect of an alkaloidal fraction from the stem bark of Artabotrys odoratissimus R. Br. on larvae of the mosquito vector of lymphatic filariasis, Culex quinquefasciatus Say, was investigated. Concentrations of 10, 20, 40, 80, 160 and 320 ppm were tested in the laboratory against larvae of various ages. A general increase in lethal concentration 50 (LC50) values from the second to fourth instars was observed. Based on overlapping confidence intervals (CIs), the LC50 value following 12 h of exposure was lowest for the second instar (59.2 ppm) and was significantly different from that recorded for the fourth instar (110.4 ppm). LC50 values decreased significantly with time (from 12 to 24 h after treatment) in all the instars. These results indicate the potential utility of the A. odoratissimus extract as a mosquito larvicidal agent, and further research is recommended.