Relict populations of Lyonetia ledi Wocke, 1859 (Lepidoptera, Lyonetiidae) from the Alps indicate postglacial host-plant shift to the famous Alpenrose (Rhododendron ferrugineum L.)

Peter Huemer,Jürg Schmid

doi:10.3897/alpento.5.76930

Abstract

Lyonetia lediWocke, 1859 (Lyonetiidae), was hitherto considered as a boreal species with a circumpolar distribution pattern and relict populations in isolated peat bogs north-east of the Alps (Austria, Czech Republic, Germany). In Europe it is known as a leaf-miner onRhododendron tomentosumStokes ex Harmaja (Ericaceae) as the primary host-plant and alsoMyrica galeL. (Myricaceae). The first record ofL. ledifrom the Swiss Alps onRhododendron ferrugineumL., the famous Alpenrose, indicates an ancient host-plant switch during postglacial periods whenR. tomentosumandR. ferrugineumshared habitat in the prealps. Conspecificity with northern populations is supported by the adult morphology and supplementing DNA barcodes (mtDNA COI gene).L. lediis the first obligatory leaf-mining species onR. ferrugineum. Details of the life-history and habitat are described and figured. The record finally substantiates the probability of an autochthonous population in Carinthia (Austria), from where the species was recently published as new to the Alps.

Highlights

New national records are of considerable faunistic interest in Europe per se, they are often disregarded of only limited scientific value
Both hitherto known European host-plants of L. ledi are characteristic of peat bogs and show a circumpolar distribution pattern
Whereas R. tomentosum is becoming increasingly rare towards the South, with only a few relict populations in peat bogs of Central Europe north of the Alps, Myrica gale is completely absent from the southern part of Central Europe

Summary

Introduction

New national records are of considerable faunistic interest in Europe per se, they are often disregarded of only limited scientific value. We report an exceptional observation of a species of microlepidoptera which is of faunistic and of considerable ecological interest as the first specialized leaf-miner on Rhododendron ferrugineum. The species discussed, Lyonetia ledi, was previously known in the Alps only from a single specimen from Carinthia, whose origin seemed questionable, especially because the known host-plants Rhododendron tomentosum (Ericaceae) and Myrica gale (Myricaceae) are absent from that area. The find was immediately surprising, as no specialized leaf-miners were previously known from this plant (Hering 1957) and usually this plant remains disregarded by lepidopterists. The suspicion that it was a member of the family Nepticulidae was rejected from larval habits. The subsequently emerged moths were identified as Lyonetia ledi both according to external morphological features and by subsequent DNA barcoding

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