Biology and damage of Thamnurgus pegani Eggers (Coleoptera: Scolytidae) feeding on Peganum harmala L. in eastern Turkey

The scolyted beetle, Thamnurgus pegani Eggers, was recorded from eastern Turkey in 2002 on Peganum harmala L. (Zygophyllaceae), a perennial weed toxic to domestic animals. The beetle's developmental stages, biology, damage, and parasitoids were studied in Igdir Province and in the laboratory at Erzurum during 2003-2005. Thamnurgus pegani is univoltine and adults hibernate in the larval galleries, root crown, and soil beneath the host plant. Overwintering beetles appear at the end of April and move to the newly developed stems. Females oviposit eggs singly in the small holes, usually between the stem and lateral shoot. The emergent larvae tunnel downward in the stem pith. A fungus, Fusarium oxysporium Schlechtend was detected within the gallery and on the body of T pegani. The fungal-infested tissue became blackishbrown. Larva feed on this infected tissue, pupate in the mined stems, and new adults appear during the first week of August. T pegani attack on P. harmala reduces seed crop size and germinability, and thus the beetle is considered to be a potential candidate for biological control of the plant in areas of the world where it has been inadvertently introduced.