توصیف لاروهای سن دوم، سوم و شفیره آفت Tephritis arsenii (Diptera, Tephritidae) از ایران

The genus Tephritis Latreille, 1804 with over 160 described species, is the largest genera of family Tephritidae in the Palaearctic region, where the larvae feed on the flowerheads of Asteraceae plants. During a study conducted in 2016 on seed-eating pests in the pastures of East Azarbaijan province, the important pest of Tephritis arsenii Korneyev was collected from flowerheads of Doronicum dolichotrichum Cavill, by sweep net. The purpose of this study is to identify the immature stages of this pest for faster control. For this purpose, a microscopic slide of important features such as the head, anterior, posterior spiracle and cephalopharyngeal skeleton and the images were taken with an optical microscope. Different degrees of ethyl alcohol and HMDS solution (hexamethyldisilazane) were used to prepare images of third instar larvae with a electron microscope in Tabriz University. Finally, the photos were named using the available sources. The second instar larva is white, slightly transparent, cylindrical, the average length is 2.5 mm and width 0.8 mm, cephalopharyngeal skeleton length is 0.3 mm, oral hooks are two-branches. Third instar larva is white, the body has 12 segments, cylindrical, larval length is 4.4 and width 1.4 mm, the end of the body is cut; gnathocephalon conical, a pair dorsal sensory organs (antenna) just behind of the anterior sensory lobes (palpus), Anterior portion of sensory lobe of the oral cavity surrounded with two long fingerlike, without oral ridges, The mouth hooks are heavily sclerotized and bidentate, cephalopharyngeal skeleton is darkly sclerotized, mandible light brown almost as long as high, the labial sclerite is black and separated from the hypostomal sclerite (its length is twice its width); the first segment of the thorax includes a pair of sensory organs, stelex and verruciform on the dorsal and ventral surfaces, the anterior thoracic spiracle bears four rounded papillae; abdominal segments with conical acanthae and verruciform sensilla; the caudal segment with several rows of sensilla and bears the posterior spiracular plates composed of three elongate oval rimae, four interspiracular processes with three to five branches and median ecdysial scar; The puparia body are distinctly segmented, with the anterior spiracle, the posterior spiracle without protruding spiracular plates. The results showed that by preparing electronic images of oral parts, spiracles, sensory organs and cephalopharyngeal skeleton, it is easy to distinguish different species from each other and provide timely management before the appearance of adult flies. The importance of this study is that electron microscope photography was done for the first time in Iran. Also, this species was identified in order to preserve the host due to the intensive feeding of the larvae and the non-destruction of the pasture. This research can be used to detect the immature stages of other species.