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.

Exploratory field surveys of the natural enemies associated with balloon vine Cardiospermum grandiflorum Swartz, an environmental weed in South Africa, Australia and other countries, were conducted in northern Argentina from 2005 to 2009. The surveys included other plant species in the genus Cardiospermum and other native Sapindaceae, permitting an assessment of the distribution and host range of the natural enemies. Seventeen phytophagous insects in five orders and ten families, and two fungal pathogens were found. The nature of the potential agents' damage, their field distribution and abundance, and the results of preliminary host-specificity testing indicated that the seed-feeding weevil Cissoanthonomus tuberculipennis (Coleoptera: Curculionidae) and the fruit-galling midge Contarinia sp. (Diptera: Cecidomyiidae) were the most promising biological control agents for C. grandiflorum outside of its native range.

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.

In a bid to develop technologies that serve grower needs for economic management of pests and diseases of hot pepper (scotch bonnet) while protecting public health and the environment, a study to assess the potential of cover cropping and/or less-risk pesticide usage in the management of pests and diseases of hot pepper was conducted for two consecutive seasons in Uganda. A split-plot randomized complete block design with three replications was used with cropping system (main plots) and pesticide treatment (sub-plots) as the factors. There were two cropping systems: the hot pepper+cowpea system vs. a hot pepper monocrop and five pesticide treatment options: (i) prophylactic treatment of plots at transplanting with granular carbofuran; (ii) weekly sprays of a neem-based formulation; (iii) combination of the prophylactic carbofuran treatment and neem; (iv) sulphur sprays at 10-day intervals (season 2 only); and (v) the untreated control. Data were collected on population dynamics of aphids, whiteflies, thrips, mites, nematodes and on plant performance parameters of branching and fruit weight. Results indicated that the hot pepper+cowpea system greatly lowered infestations of aphids and nematodes on hot pepper, but did not decrease thrips and whiteflies; and brought about a yield penalty on hot pepper. Prophylactic applications of carbofuran and/or sprays of a neem-based formulation lowered populations of aphids and whiteflies on hot pepper to varying extents; and increased yield of pepper.

The life cycle of the koinobiont endoparasitoid Platygaster diplosisae Risbec was investigated to assess its suitability as a biological control agent of the African rice gall midge Orseolia oryzivora Harris & Gagné. Screen house and laboratory experiments were conducted in 2008 under ambient conditions in Ibadan, Nigeria. Morphological characteristics of the parasitoid's immature stages were observed, and its life cycle parameters were measured. The parasitoid's average egg incubation period was 12.9 days, and on average, 67.3% of eggs hatched. Three instars occurred, with average developmental durations of 2.2, 0.5 and 2.5 days for the 1st, 2nd and 3rd instars, respectively. Pupal development took 6.7 days until adult emergence. Pre-oviposition period averaged 12.1 h, and a female laid on average 95.2 eggs, with a mean oviposition period of 3.5 days. The longevity of males and females was 3.0 and 4.1 days, respectively, without food; longevity was extended when honey and water were provided. Mating and oviposition behaviours were recorded, and a sex ratio of eight females to one male was found in parasitoid progeny. The parasitoid had a total developmental period of 27.3 days, which is about 5 days longer than that of its host. In conclusion, P. diplosisae can play an important role in the biological control of O. oryzivora on rice, and should be conserved in African rice production systems.

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.

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.

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.