Phloeosinus aubei Perris and Phloeosinus armatus Reitter
Common names: Phloeosinus aubei: Small cypress bark beetle, P. armatus: Cyprus shoot beetle.
Systematic position: Insecta, Holometabola, Coleoptera, Curculionidae.
Geographical Distribution: Mediterranean region, Central Europe.
Morphology: The adult of P. aubei is 2-2.7 mm in length, that of P. armatus is larger, about 4.5 in length, and bears 2 pairs of dark protuberances on the posterior margin of its elytra. The dorsum of both species bears many small depressions and short hairs. The thorax is darker than the brownish elytra, which carry pronounced longitudinal stripes. The larvae are whitish, with strong segments and a brown head.
Host plants: Cypress (Cupressus sempervirens L. and Cupressus macrocarpa Hartw.), Juniperus chinensis L., Chamaecyparis obtuse (Siebold & Zucc.) Endl., and several Thuja spp.
Life history: The beetles raise 3-4 annual overlapping generations, a life cycle requiring about 2 months. The adults excavate irregularly-curving tunnels, feeding galleries with nuptial chambers, in the sapwood. They also bore short, unbranched tunnels into small one-year-old shoots, wherein they lay about 50 eggs/female, and the larvae feed. The galleries made by P. armatus are much longer than those of P. aubei. Both species also bore hibernation galleries, which consist of a single larva. Phloeosinus armatus develops throughout the year, and arrives at host trees earlier than P. aubei, which infests the trees only in spring.
Economic damage: Both beetles are usually considered to be secondary invaders of stressed and unhealthy trees. Feeding causes shoots to turn red and dry. Tree growth (in height and in diameter) is curtailed; severe damage, and even tree death, may ensue during prolonged droughts. In Italy P. aubei is regarded as a destructive pest of cypress. In addition, both beetles also transmit Coryneum canker, a serious disease of cypress, caused by the fungus Seiridium cardinal (Wagener) Sutton et Gibson. If uncontrolled, the disease can destroy the trees, leading to eventual death.
Monitoring: The occurrence of more and longer galleries which develop in unpruned trap-logs of C. sempervirens, as compared to pruned logs. This indicates that unpruned logs are more suitable for monitoring and studying the pests.
Horticultural control: Trap logs may be used to suppress most of the pests. Removal of trees with P. armatus infestations, along with any infested branches cut due to thinning and pruning.
Biological control: Several parasitoids of these pests were collected, of which the pteromalid Metacolus unifasciatus Förster was the more common. Other parasitoids belong to the families Bethylidae, Braconidae, Eupelmidae and Eurytomidae](entry/Eurytomidae), and along with predaory beetles, may kill many of the pests’ populations.
Bel Habib, R., Ben Jamâa, M.L., and Nouira, S. 2007. Biological characteristics of the cypress bark beetle Phloeosinus aubei in the Kessra forest, Center of Tunisia. Tunisian Journal of Plant Protection 2: 99-108.
Bozsik, G. and 2017. Phenology, behavior and infestation levels of the invasive small cypress bark beetle, Phloeosinus aubei, on some cultivars of Thuja and Juniper spp., in Hungary. Phytoparasitica 45: 201-210.
Bozsik, G., Tröger, A., Francke, W. and Szőcs, G. 2016. Thuja occidentalis: identification of volatiles and electroantennographic response by the invasive cedar bark beetle, Phloeosinus aubei. Journal of Applied Entomology 140: 434-443.
Ciesla, W.M. 2004. Forests and forest protection in Cyprus. Forestry Chronicle 80: 107-113.
Mendel, Z. 1983. Effects of pruned and unpruned trap-logs of cypress on infestation and development of two Phloeosinus species. Phytoparasirica 11: 83-88.
Mendel Z. 1984. Life history of Phloeosinus armatus Reitter and P. aubei Perris (Coleoptera: Scolytidae) in Israel. Phytoparasitica 12: 89-97.
Olenici, N, Mitroiu, M-D., Knižek, M. and Olenici, V. 2015. Parasitoids of Phloeosinus aubei (Coleoptera: Curculionidae) from Romania. Acta Zoologica Bulgarica 67: 293-295.
Pennacchio F., Danti R., Benassai D., Squarcini M., Di Lonardo V., Roversi P.F 2013. A new additional record of Phloeosinus armatus Reitter from Italy (Coleoptera Curculionidae Scolytinae). Redia 96: 45-50.
Solel, Z., Messinger, R., Golan, Y. and Madar, Z. 1983. Coryneum canker of cypress in Israel. Plant Disease 67: 550-551.