Thysanoptera of date palm: First records from Biskra (Algeria)

Abstract

The Algerian province of Biskra accounts for most of the date production in the country, especially high-quality dates for export. This crop is threatened by many pests, but the presence and effects of thrips are unknown. A survey of date palm thrips was conducted in Biskra province, located in an arid zone of Algeria, in four palm groves (two eastern, two western).Ten trees were selected randomly in each grove. Thrips were collected from four fronds (leaves) on each tree, one frond from each of the four cardinal directions, by shaking them over a white plate. Thrips also were collected from inflorescence samples by shaking one floral branchlet from an inflorescence at each cardinal direction over a white plate. Dislodged thrips were gathered into vials containing 60% ethanol and later mounted on slides and identified to the species level. Nine thrips species were collected, all being new records for Algeria and Biskra province: Aeolothrips intermedius Bagnall, 1934, Bolothrips icarus (Uzel, 1895), Frankliniella occidentalis (Pergande, 1895), Kakothrips pisivorus (Westwood, 1880), Liothrips vaneeckei Priesner, 1920, Melanthrips fuscus (Sulzer, 1776), Odontothrips loti Haliday, 1852, Thrips minutissimus Linnaeus, 1758 and Thrips tabaci Lindeman, 1889. Bolothrips icarus, a fungal feeder, was the most frequently collected species (>25% of all specimens), followed by F. occidentalis, a widespread and polyphagous species that can cause economic damage. Other species were less frequent but still pose a potential threat to date palm production in this region. A key was developed for the thrips species collected in this study.