Hylesinus oleiperda (Fabricius)
Taxonomic placing: Insecta, Holometabola, Coleoptera, Curculionidae, Scolytinae. (Formerly in the family Scolytidae.
Common name: Olive bark beetle, Barrenillo Negro.
Morphology: The body is almost-black, 2.5-3.0 mm long, covered with short yellowish hairs. The thorax is black, minutely punctated. The elytra are dark-brown, longitudinally striated and the antennae are club-like, red. The larva (often called “grub”) is apodous, body curved, thorax enlarged.
Geographical distribution: Central Europa, the Mediterranean Region, South America (Argentina, Chile and Peru).
Host plants: Olive, Ash (Fraxinus syriaca Boiss.), lilac (Syringa vulgaris L.) and privet (Ligustrum vulgare L.).
Life history: This beetle is usually univoltine. The adults appear in the spring, each mated female boring a hole in the bark of weakened host (usually olive) trees and then bores horizontal galleries in which it lays 40-50 eggs. The emerging larvae bore their own galleries, usually in thin stem and branches, wherein they feed for about 10 months and then pupate. On freshly-cut olive branches they may be bivoltine, the adults appearing in the spring and autumn. The adults communicate by making attraction chirps.
Economic damage: The weakening of branches, or even their breaking off, can result in loss of fruitful buds and inflorescences, negatively affecting normal olive growth.
Management
Monitoring: Noting the holes made in the bark of weakened Branches and the excreted frass.
Horticultural methods Maintaining tree health; removal of infested twigs and branches and young trees.
Chemical control: A carbamate and an organophosphate, applied to the entrances of the galleries, provided good control.
Biological control: In Tunis the endoparasitoids Cheiropachus quadrum Fabricius (Pteromalidae) and Dendrosoter protuberans (Nees) (Braconidae) killed more than 70% of the pest population. The larva is also attacked by the pteromalid Cheiropachys colon (L.) and Eurytoma morio Boheman (Eurytomidae).
References
Graf, P. 1977. Ein Beitrag zur Biologie und Bekampfung von Hylesinus oleiperda F. (Coleopt., Scolytidae) auf Olive in der Tadla (Marokko). Zeitschrift fur Angewandte Entomologie 83: 52-62.
Holgado, M.G., Becerra, V.C., Mácola, G.S. and Llera, J. 2000. Insecticidas para control de Hylesinus oleiperda F. Revista de la Facultad de Ciencias Agrarias, Universidad Nacional de Cuyo 32: 9-14.
Jardak, T., Moalla, M. and Ksantini, M. 2002. Mortality factors affecting population dynamics of the scolytid Hylesinus oleiperda Fabr. (Coleoptera, Scolytidae). Acta Horticulturae 586: 823-826.
Rudinsky, J.A. and Vallo, V. 1978. The ash bark beetles Leperisinus fraxini and Hylesinus oleiperda: stridulatory organs, acoustic signals, and pheromone production. Zeitschrift für Angewandte Entomologie 87: 417-429.