Bulletin of Insectology 67 (1): 73-79, 2014 ISSN 1721-8861 Genetic patterns, host use and larval morphology in Tunisian populations of Orgyia trigotephras Olfa EZZINE 1,5 , Axel HAUSMANN 2,3 , Manuela BRANCO 4 , Yaussra MANNAI 1,5 , Samir DHAHRI 1 , Said NOUIRA 5 , Mohamed Lahbib BEN JAMÂA 1 1 Laboratoire de Gestion et de Valorisation des Ressources Forestière, National Institute for Research in Rural Engi- neering, Water and Forest (INRGREF), Ariana, Tunisia 2 Bavarian State Collection of Zoology (ZSM), München, Germany 3 Staatliche Naturwissenschaftliche Sammlungen Bayerns (SNSB), München, Germany 4 Instituto Superior de Agronomia Centro de Estudos Florestais (CEF), Universidade de Lisboa, Portugal 5 Faculté des Sciences de Tunis, Campus Universitaire, El Manar, Tunis, Tunisia Abstract Orgyia trigotephras Boisduval 1829 (Erebidae Lymantriinae) is a polyphagous moth widely distributed across the Mediterranean Basin. Current taxonomy validates several taxa at subspecies level within this species. Two of them, Orgyia trigotephras anceps Oberthur 1884 and Orgyia trigotephras transiens Staudinger et Rebel 1901 were found to occur in Tunisia. Although considered a rare species in southern Europe, an extensive outbreak was observed in Tunisia in the last decade. In this paper we present details on genetic patterns (mitochondrial DNA marker CO1), on larval phenotypic traits and on host plant species of Tunisian popula- tions of O. trigotephras. Tunisian specimens clearly differentiated into two lineages, restricted to western and eastern Tunisia re- spectively. Both Tunisian haplotype-lineages strongly diverge from southern Spanish and southern Italian „conspecifics‟, ques- tioning current taxonomy. Furthermore, we describe four larval phenotypes occurring in Tunisia and register Quercus coccifera, Quercus suber, Erica multiflora and Pistacia lentiscus as the four main host plant species. There was no association of the two genetic lineages with larval phenotypic traits. However, host plant species differed significantly between the two lineages. Key words: Orgyia trigotephras, phylogeography, CO1, host plants, larval phenotypes. Introduction Orgyia trigotephras Boisduval 1829 (Erebidae Lyman- triinae) is a xerothermophilous tussock moth that feeds on evergreen oaks and other Mediterranean shrub spe- cies. The moth is widely distributed across the Mediter- ranean Basin, from Anatolia (Patočka and Turčáni, 2008) to south-western Europe, France (Berard et al., 2010), Spain (Montoya and Masmano, 1993) and North Africa (Villemant and Fraval, 1993). Several subspecies are currently recognized: Orgyia trigotephras corsica Boisduval 1834 from Corsica (Bella et al., 2011; but validated at species rank in de Freina and Witt, 1987); Orgyia trigotephras anceps Oberthur 1884 from Mo- rocco (Daniel and Witt, 1975); Orgyia trigotephras sicula Staudinger et Rebel 1901 (=Orgyia trigotephras calabra Stauder 1916) with a characteristic dark brown wing and body coloration from southern Italy, Sicily and Malta (Stauder, 1923; Bella et al., 2011); Orgyia trig- otephras transiens Staudinger et Rebel 1901 (=Orgyia trigotephras panlacroixii Oberthur 1876) from North Africa (de Freina and Witt, 1987) and Orgyia trig- otephras holli Oberthur 1916 (=O. trigotephras panla- croixii) from Algeria. In Tunisia, two taxa were re- corded: in the northwest (Aïn Draham) O. trigotephras transiens (Lord Rothschild et al., 1917), and O. trig- otephras anceps in the north (Bizerte) and the northeast (Cap Bon) (Chnéour, 1955). So far, no molecular works were conducted to clarify their taxonomic status. Life history of O. trigotephras has not been studied comprehensively, so far. Nevertheless, the few existing records suggest differences between regions. In Spain, Italy and Algeria the species is reported to have one generation per year overwintering in the egg stage, with a flight period of the adults from May to August (Ortiz and Templado, 1973; Chakali et al., 2002; Bella et al., 2011). In Tunisia O. trigotephras is bivoltine with a first generation from April to June and a second generation from October to December (Chnéour, 1955; Ezzine, 2007). In Corsica the species is bivoltine too (Bella et al., 2011). Females have reproductive capacity up to 200 eggs (Ezzine, 2007), they are apterous and thus show no dispersal at the adult stage. Mating and egg deposition take place on the same plant where pupation occurs. Dispersal is larger in the larval stage, early in- stars larvae are transported by wind, caterpillars of later instars usually move from one plant to another, but this type of dispersal is usually limited to neighbouring plants (Ezzine, personal observation). O. trigotephras is considered to be polyphagous. In southern Italy, Orgyia trigotephras etrusca Verity 1905 (=O. trigotephras sicula) is found feeding on and spo- radically causing defoliation of Pistacia lentiscus (Bella et al., 2011), whereas in Sicily and Malta, the subspe- cies O. trigotephras calabra feeds mainly on Sarotham- nus sp. (Bella et al., 2011). In southern Spanish dune habitats (Ayamonte), O. trigotephras prefers Retama monosperma (Dionisio, 2002), whilst in the north- eastern region of Albacete in Spain O. trigotephras is one of the main lepidopteran species found on Quercus ilex (Montoya and Masmano, 1993). In Morocco and Algeria the subspecies O. trigotephras anceps was found to feed mainly on evergreen oaks, Quercus suber and Q. ilex (Villemant and Fraval, 1993; Chakali et al.,