Bulletin of the Entomological Society of Malta (2009) Vol. 2 : 53-55
Phyllonorycter trifasciella (Haworth, 1828), new record for the Maltese Islands (Lepidoptera: Gracillariidae) Michael ZERAFA1 ABSTRACT. Phyllonorycter trifasciella represents a new record for the Maltese Islands. A short description, distribution, and biology including larval food plants of this species are included. KEY WORDS. Lepidoptera, Gracillariidae, Phyllonorycter trifasciella, Maltese Islands, new record. INTRODUCTION The Family Gracillariidae has a worldwide distribution and currently accomodates 98 genera with 1,809 described species (De Prins & De Prins, 2005). In Europe this group is represented by 26 genera within three subfamilies, the Gracillariinae with 91 species, the Lithocolletinae with 138 species and the Phyllocnistinae with 9 species (Buzsko, 2004). The principal character separating the Gracillariidae from other families is the hypermetamorphosis of the larva. During the first instar, the larva mines the epidermal cells of leaves or, less often, the tender bark and obtains its food via sap-sucking. After the second or third ecdysis the larva feeds on the parenchyma in the normal manner of lepidopterous larvae, a change necessitating a major restructuring of the head-capsule and mouth parts (Emmet, 1985) The four known gracillarid species in Malta include Dialectica scalariella (Zeller, 1850), Caloptilia coruscans (Walsingham, 1709), Phyllonocnistis citrella (Stainton, 1856) (Sammut, 2000), and Phyllonorycter messaniella (Zeller, 1846) (Sammut & Mifsud, 2008). The present work provides information on a fifth species recently found in Malta.
Phyllonorycter trifasciella (Haworth, 1828) Material examined: MALTA: Għargħur, Wied Anġlu, 5.iii.2007, 1 ex., (by beating), 8.ii-30.iii.2009, 8 exs., (ex-larva); Mellieħa, Għajn Żnuber, 21.iii-6.iv.2009, 6 exs., (ex-larva); Naxxar, Naxxar Gap, 23.xii.2007, 1 ex., (by beating), 3.iii-25.iv.2009, 26 exs. (of which 8 exs. on Scabiosa maritima L.); Naxxar, 20.v.2009, 1 ex., (at light). All examined material was collected by the author. Ex-larvae material was collected from Lonicera implexa Ait.
Short description: Wing span 6.5 - 9 mm (n = 43). Adult as in fig. 1. Head with a vertical tuft orange brown becoming whitish at the back. Labial palps whitish. Antenna ¾ of wing length, fuscous banded off-white. Thorax orange brown. Forewing orange brown sometimes pinkish; 1
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two white fascia one at one fifth and the other at one half from base. The first sinuate outwards in the costal half, the second angled outwards in the costal half less so in the dorsal half. Both fascias preceded with black; the first a wide patch in the costal half being reduced to a line in the other half, the second similar but widening in the dorsal half. Two costal strigulae and one dorsal beyond fasciae; all white, first costal and dorsal opposite each other at two thirds and curving outwards. Both preceded with black scales, widest on costa. A black stripe extends from the meeting point widening towards the fringe. The second costal strigula close to apex curving inwards, sometimes preceded by a few black scales. Black apical spot, often extending to second costal strigula. Cilia light orange brown from apex to tornus, light grey on dorsum. Hind wings grey with fuscous scales. Cilia greyish brown. Abdomen brownish grey.
Figure 1 - Phyllonorycter trifasciella, adult. Figure 2 - Leaf-mine on Lonicera implexa. Distribution: The species is found throughout Europe including Corsica, Sardinia and Central Russia (Buzsko, 2004). Ecology: The egg is laid on the underside of the leaf, generally close to the mid rib and almost always on the outer half. The larva, which is of a yellowish green colour with a light brown head, mines inside the leaf. The mine starts as a flat blotch on the underside. As the larva grows it contracts the lower epidermis to create a pocket. The contraction is diagonal to the leaf, bending it and in the majority of cases forming a cone (Fig. 2.). Pupation takes place inside the mine. The pupa is of a light brown colour. Locally, the larva was found to feeds on Lonicera implexa Ait. & Scabiosa maritima L. In Naxxar, mines were also found on Lonicera caprifolium L. Elsewhere, the species was known from Lonoceria spp., Symphoricarpos rivularis Suksdorf and Leycesteria formosa Wallich (Emmet, 1985). On the continent, the species is on the wing in May, August and November (Emmet, 1985). Locally, adults have been recorded on the wing in December and again from late February to May in probably overlapping broods. Acknowledgements I would like to thank Mr Paul Sammut of Rabat, Malta for his assistance during the present work.