Hexamermis eurygasteri n. sp. (Nematoda: Mermithidae) parasitising the sunn pest Eurygaster integriceps Puton (Hemiptera: Scutelleridae) in Turkey Gulcan Tarla • George Poinar • S ¸ . Tarla Received: 20 December 2010 / Accepted: 8 February 2011 Ó Springer Science+Business Media B.V. 2011 Abstract A new species of mermithid nematode, Hexamermis eurygasteri n. sp. (Nematoda: Mermithi- dae) is described as a parasite of the sunn pest Eurygaster integriceps Puton (Hemiptera: Scutelleri- dae) in Turkey. The combination of the following characters separate H. eurygasteri from other members of Hexamermis Steiner, 1924, as defined by Artyuk- hovsky (1990) and Kaiser (1991): amphidial pouch integrated into lateral cephalic papillae; amphidial openings minute; well-developed cuticular vulval cone; small vulval lips; vagina straight or slightly curved at tip, without reverse bend; spicules shorter in length than body diameter at cloaca; spicules straight, except occasionally for short bend at base; spicule tips bluntly rounded; and two double rows of genital papillae. This is the first description of a nematode parasite of a member of the Scutelleridae and the first description of a mermithid nematode from Turkey. This mermithid has potential as a biological control agent in an inte- grated control programme of the sunn pest. Introduction Nematode parasites of Hemiptera are relatively rare and most remain undescribed. However, mermithids have been reported from at least 17 species of hemipterans, with a single record of an undescribed species in scutellerids (Poinar, 1975; Artyukhovsky, 1990). The sunn pest Eurygaster integriceps Puton (Heteroptera: Scutelleridae) is one of the most important pests of wheat in West and Central Asia and in Eastern Europe (Critchley, 1998). This bug is univoltine and only part of its life-cycle is spent in wheat fields. Adults of the new generation migrate to the mountains before the harvesting of wheat and barley begins. They remain in aestivation and dia- pause under bushes and litter on the mountains for about nine months. During this period various natural enemies and entomopathogenic diseases appear to play an important role in reducing populations of this pest. A mermithid infection was discovered while conducting a field survey of E. integriceps in over- wintering areas as part of a study on tachinid parasitism (Diptera: Tachinidae). The nematode was determined to represent a new species of Hexamermis Steiner, 1924 and is described below. Materials and methods The following description is based on two females and six males. The nematodes were obtained from G. Tarla Á S ¸ . Tarla Department of Organic Agriculture Program, Vocational High School, Us ¸ak University, 64800 Sivaslı, Us ¸ak, Turkey G. Tarla e-mail: gulcan.tarla@usak.edu.tr G. Poinar (&) Department of Zoology, Oregon State University, Corvallis, OR 97331, USA e-mail: poinarg@science.oregonstate.edu 123 Syst Parasitol (2011) 79:195–200 DOI 10.1007/s11230-011-9299-6