Population dynamics of the larvae of Eldana saccharina Walker, Chilo zacconius Bleszynski and Sesamia spp. on sugar-cane was studied over a period of 3 years, by regular sampling. Analysis of results indicated that during the first rainy season (March-June) the borer populations were low. However, the larval population increased considerably during the dry season and declined gradually during the second rainy season (September-November). Rainfall in Southern Ghana is typically bimodal, but it is occasionally evenly distributed throughout the year. When rainfall was evenly distributed, borer populations remained consistently low throughout the year. Flooding reduced the population of E. saccharina larvae in the field. Though the stem-borers showed preference for relatively younger canes, the type of borers present and their proportions varied with the sugar-cane phenology.

Female Eldana saccharina Walker was found to lay 327 ± 17.1 eggs within a period of 4 days and required three surfaces to lay eggs which were mainly deposited on the inner side of leaf sheaths fitting tightly on to the sugar-cane stalk. The mated females laid more eggs per female (327.0 ± 17.1) than virgin females (212.3 ± 5.5). The incubation period of the eggs of E. saccharina was found to be 5.64 ± 0.01 (5–7) days in the laboratory and 5.82 ± 0.03 (5–7) days in the field. The mean larval duration was 31 days and pre-pupal period lasted 2.05 ± 0.05 days. Larvae were found to exude a brownish liquid from their mouth in the direction of the invading predators. The newly hatched larvae spread out in 1–3 days of hatching. The mean growth ratio of the larval instars was 1.54 ± 0.05. Pupae frequently occurred very close to the exit hole (less than 5 cm) and the pupal period varied from 7 to 13 (9.76 ± 0.05) days. The life cycle of E. saccharina was completed in 49 (36–62) days. The pre-oviposition period was 2 days and the female reproductive life lasted 4 days. It takes about 53 days for a succeeding generation to be produced. Adults of E. saccharina survived from 6 to 13 days. Adults reared from field collected larvae snowed a sex ratio of 42:51 which was significantly different from 1:1 in the laboratory bred stock, at the 5% level of probability. A comparison of the life cycle of E. saccharina populations in Ghana and Uganda suggests the existence of two biotypes of the pest.

Background. Tema, Ghana's main industrial city, has many areas that are suspected to be contaminated by lead. Elevated lead levels can affect, among many other issues, mental development, kidney function and blood chemistry. Children are particularly at risk. Objectives. The objective of this study was to determine the concentration of lead in soil from selected sites in Tema and how these levels relate to local pediatric blood lead predictions. Methods. A total of 47 surface soil samples were taken from 9 different sites. Energy dispersive X-ray technique was employed to determine the levels of lead. Pediatric blood lead levels were estimated using the Integrated Exposure Uptake Bio-Kinetic Model For Lead in Children, developed by the U.S. EPA. Results. The study revealed that the selected sites are highly contaminated by lead. In particular, the concentration of Pb in soil at a used lead acid battery recycling facility exceeded regulatory limits for industrial soil as set by the U.S. EPA. The model for predicting concentrations of lead in the blood of age-specific children showed extremely high probabilities of BLLs exceeding regulatory limits. Conclusions. Based on the results of soil testing, sites that were expected to reveal lead exposure positively demonstrated high levels of contamination, in some areas exceeding U.S. and other national regulatory limits. This information is expected to help authorities make informed clean-up decisions.

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