A survey of field insect pests of cereals in Kisoro District.

Abstract

A variety of different insects attack cereals. Insect pests are responsible for two kinds of damage to growing crops, direct injury done to the plant by the feeding insect and transmitting diseases. Insect pests are some of the major constraints limiting yield of cereals in Kisoro district. The objective of this study was to determine the effects of insect pests on cereal crops in Kisoro, specifically identifying them, determine the damage they cause and economic loss. A survey was conducted in three sub counties in Kisoro district (Figure1). Five gardens of each of the cereals were randomly selected from each of these sub counties for the samples. The sampling sites were divided into four quadrates and five plants were selected within the square meter at random from each part. Questionnaires were also used to collect information from the farmers. Samples of insects were identified from the field and laboratory. Damage assessment was done by clear observation of sampled plants for damage on leaves, stems and grains for severity. Yield loss was estimated using the formula: Yield in pest-free garden (YPFG) – Yield in garden with pests (YGWP). Insect pests identified were; Russian wheat aphid, armyworm, English grain aphid, corn earworm, white flies, brown wheat mite, corn leaf aphid, lesser cornstalk borer, sugarcane borer, flea beetles, sorghum head caterpillar, mites. It was discovered that Russian wheat aphid had the highest frequency 500 severity of 4 in Nyarusiza. Among pests maize, corn leaf aphid had the highest frequency. For sorghum, corn aphid had the highest frequency in all the sub counties. Wheat has the highest yield loss of about 80.9% when there is no pest control. Sorghum had the lowest percentage yield loss of 6.79%. It was found out that most of the farmers were females