Composition and diversity of xylophagous and predatory beetles in Vachellia xanthophloea (Benth.) P.J.H.Hurter (Fabales: Fabaceae) at Kenyatta University and Mitaboni, Kenya

Abstract

Xylophagous beetles cause damage to Vachellia xanthophloea (Benth.) P.J.H.Hurter by burrowing and tunneling damaged or deadwood resulting in extensive frass-filled galleries. A study was conducted from 2016 to 2018 to evaluate the composition and diversity of the xylophagous beetles. Fresh infested pieces of V. xanthophloea were collected from Mitaboni and Kenyatta University (KU), Kenya, and kept in KU laboratories for adult emergence. We recorded 7,959 and 7,804 beetles in KU and Mitaboni, respectively. The families included Bostrichidae, Bothrideridae, Buprestidae, Ciidae, Cerambycidae, Cleridae, Curculionidae, Dermestidae, Histeridae, Laemophloeidae, Lyctidae, Ptinidae, Silvanidae, Staphylinidae, Tenebrionidae, Trogossitidae, and Zopheridae. Ptinidae was present in Mitaboni only, while Ciidae and Zopheridae were unique in KU. Bostrichidae was the most abundant family accounting for 28.82% and 57.27% beetles followed by Curculionidae at 15.00% and 20.46% in KU and Mitaboni, respectively. Xylion adustus (Fahraeus) (Bostrichidae) accounted for 24.73% in KU, while Sinoxylon ruficorne Fahraeus (Bostrichidae) accounted for 24.83% in Mitaboni. Species richness (S), Shannon diversity index (H), and evenness (J) were higher at Mitaboni (S=54; H=2.45; and J=0.614) than KU (S=51; H=2.33; and J=0.596). Further studies should be conducted to document and enrich knowledge on diversity and distribution of the species associated with decaying V. xanthophloea.