Xylotrechus quadripes (Chevrolat), the coffee white stemborer (CWSB), is a major pest of arabica coffee (Coffea arabica L.) in some Asian countries. The CWSB was first reported in India in 1838. CWSB larvae make galleries in the main stem and thick primary branches of coffee plants. The pest causes substantial economic loss every year because infested plants have to be uprooted. The borer completes its life cycle in 1 year. There are two to three population peaks in 1 year and emergence periods depend on climatic conditions. Several natural enemies (parasitoids, predators and pathogens) and some alternative host plants of this borer have been recorded. Integrated management, i.e. cultural, mechanical, sex pheromone and chemical methods, has been adopted to control the stemborer. This review summarizes the most important work carried out on the bioecology and integrated management of X. quadripes. Also, we briefly discuss the need for future studies for better management of the CWSB.

The variation in demographic parameters (namely survival and fecundity, intrinsic rate of natural increase pre-reproductive period and relative growth rate) was used to assess the resistance of cowpea landraces (namely B261-B, B383, B013-F, B339 and Blackeye, as a check) against cowpea aphid (Aphis craccivora Koch). The experiment was carried out from 18 March 2011 to 5 April 2011. The demographic parameters of A. craccivora differed significantly among varieties, supporting our prediction that cowpea landraces resistant to cowpea aphid would have a significant effect on the demographic parameters of the aphid. We recorded significantly lower survival, fecundity, intrinsic natural rate of increase and relative growth rate on the landraces B261-B and B383 compared with the other landraces. A significant delay in the pre-reproductive period was also found on B261-B and B383. The results showed that landraces B261-B and B383 have an increased level of resistance as shown by the extended pre-reproductive period and the reduction in population growth rate, survival and fecundity. This information will be used in the characterization of the landraces before being incorporated in the breeding programme in Botswana.

A study to determine the species richness and spatial distribution of five meliponine bee species in three different habitats in the Kakamega forest was undertaken for the first time. Two forest (indigenous and mixed indigenous) and two grassland (with Eucalyptus spp. trees and indigenous trees) types, along with homesteads (in the vicinity of mixed indigenous forest and indigenous forest, respectively), were surveyed. Line transect methods were used in the nest survey in each habitat. The highest number of species was recorded in the indigenous forest, while no nest was discovered in the grassland with Eucalyptus spp. trees. The mean number of nests per transect was higher in homesteads followed by the indigenous forest. The nesting pattern of almost all species nesting in the indigenous forest, mixed indigenous forest (Meliponula bocandei [Spinola]) and grassland with indigenous tree species (Meliponula ferruginea [Lepeletier] reddish brown) was dispersed. The nesting pattern of M. ferruginea (reddish brown) and Hypotrigona gribodoi (Magretti) changed from a dispersed and random pattern, respectively, to a clumped nesting pattern when nesting in homesteads. The degree of nest clustering was low for M. ferruginea (reddish brown) and high for H. gribodoi. Differences in average nearest-neighbour distance were observed within species nesting in a dispersed or clumped pattern. This study reveals that habitat type in the Kakamega forest influences the species richness and nesting pattern of the five stingless bee species.

Pebrine caused by Nosema bombycis in the silkworm Bombyx mori L. causes severe economic loss to the sericulture industry. Several species of microsporidia and strains of N. bombycis have been isolated from infected silkworms. The study of the developmental stages of any parasite is important, as it leads to the identification of stages that may be susceptible to control measures. For this study, five microsporidian isolates from B. mori were collected from five different locations in West Bengal, India and a study of the developmental stages from mid-gut smears and histological techniques was undertaken. The observations of mid-gut smears and histological specimens revealed differences in the morphometry and duration of different developmental stages of the parasites.

Inhibition of okra growth in response to flea beetle injury was studied in both the screen house and field. In the screen house or field, 0, 5, 10, 20, 30 and 40 pairs of Podagrica uniforma (Jacoby), representing six treatments, were introduced into different cages containing five 3-week-old okra plants, replicated three times. Data were collected on the number of flowers and branches, plant height, stem girth and functional leaf area in both experiments. With increasing densities of P. uniforma, days to 50% flowering and fruit initiation were prolonged by 1–13 days and 2–15 days, respectively. The beetle did not exhibit florivory but caused distortion of okra fruits, i.e. bending of fruit tips at the point of flea beetle-induced damage. From the 20-pair level (eight beetles per plant), there were significant reductions in plant height (up to 50%) and stem girth (up to 43%) in both the screen house and field. The number of distorted fruits showing bent tips was significantly higher relative to the control from the 5-pair level, and was more than 90% at the 40-pair level. Regression analysis indicated that plant height was a linear function of flea beetle population. Third-degree polynomial models best described the relationship between insect density and the number of bent fruits. χ2 analysis showed that these models derived from the screen house data were not significantly different from the field data models.

This study set out to explore the influence of trap crops designated for the management of Crocidolomia pavonana (Fab.) on two other frequent pests of cabbage: diamondback moth [Plutella xylostella (L.) and cabbage aphid (Brevicoryne brassicae (L.)]. The three pests were offered six hosts in the genus Brassica: kale (B. oleracea var. acephala), cauliflower (B. oleracea var. botrytis), broccoli (B. oleracea var. italica), Chinese cabbage (B. campestris L. ssp. pekinensis), Indian mustard (B. juncea (L.) Czern.), and white cabbage (B. oleracea var. capitata) in multiple (where all the six were offered at the same time) and two-crop trials (where each of the different hosts was paired with cabbage, including a control of cabbage in monoculture) in field trials. Oviposition was considered as a measure of preference for C. pavonana and P. xylostella while colonization and reproduction were measures of preference for B. brassicae. The treatments were arranged in a complete randomized block design with four blocks. The experiment was carried out in the field in 2007 and 2008. The results indicated that C. pavonana oviposition on cabbage was consistently lowered in trap crop treatments when compared with monoculture. The results for P. xylostella and B. brassicae were not as consistent and there was a great deal of variation. It was clear, however, that trap cropping for the control of C. pavonana would not worsen pest problems with the diamondback moth or the cabbage aphid.