Survey of insect-pests of citrus crop in Eritrea

Abstract

Citrus is the main fruit crop in Eritrea with the main citrus species being orange, lemon and mandarin that are produced in 2064, 328 and 17 ha, respectively. The production and productivity of these fruit crops are affected by several pests. Citrus pest survey was conducted in major citrus growing regions of the country with the objectives to assess the type of citrus insect-pests in the different areas, study the natural enemies of the citrus pests and assess the nature of pest damage on the fruit crop. Pest assessments and counts by species were done using hand lenses under field condition and microscope in laboratory. The result of the study showed that citrus is affected by 21 different species of arthropods out of which 19 are insect species and the remaining 2 species are Acarina (mites). The insect pests cause citrus tree damage at different stage and on different parts of the tree such as leaves, stem, fruit and root. Of the 21 species, six are major pest and the remaining 15 species are minor pests. The six important pests are leaf miner, red scale, black scale, fruit fly, whitefly and red spider mites. Leaf miner, fruit fly and red spider mites were observed in all citrus production areas while the remaining three species were recorded in limited areas. Black and red scales incidence and severity were high in Hamelmalo, Elabered, Alla, and Durfo. Fruit fly is the main pest of citrus throughout the fruit producing areas of the country, threatening its production and cause 20-40 percent fruit dropping and rotting.