فعالیت فصلی و زیست شناسی سرخرطومی ساقه خوار بیلهر Lixus pulverulentus Scopoli, 1763 (Coleoptera: Curculionidae) در منطقه یاسوج

Bilhar, Dorema aucheri (Apiaceae), is native plant belong to Mediterranean basin, southwest and central Asia. It grows in the mountains of western of Iran (Sedeh and Kermanshah) and in Persian it is called Kandale kohi and in Kermanshah its known as Zo. Their reproduction is entirely by seed and the plants are biennial. The biology of bilhar stem-boring weevil, Lixus pulverulentus Scopoli, was studied on Dorema aucheri in laboratory and rangelands in Yasouj. The results of this study showed that, the stem-boring weevil has a single generation per year and overwinters as adult whithin the dried stems of host plant. The adults emerge from the dead stems, in late April. After emerging, they start to feed on the leaf tissues of host plant and mate from time to time. Then females chew holes into the stem, and lay eggs singly the each hole. Females cover their eggs with plant fiber that had been chewed away to make the hole for protection. Each female laid a mean of 32±2.41 eggs during her life span. Eggs hatch 7-9 days after oviposition and the young larvae bore into the stem and feed on the tissue. The full grown larvae produce pupal cell in the stem and eventually pupate. After 10-14 days, pupa develops into a new generation of adults within the stems in summer. These adults remain inactive in the dried stems until the following spring. The total life cycle from egg to adult ranges from 39 to 49 days under natural conditions.