Phyllonorycter maestingella ( Müller, 1764 )

Landry, Jean-François, Nazari, Vazrick, Dewaard, Jeremy R., Mutanen, Marko, Lopez-Vaamonde, Carlos, Huemer, Peter & Hebert, Paul D. N., 2013, Shared but overlooked: 30 species of Holarctic Microlepidoptera revealed by DNA barcodes and morphology, Zootaxa 3749 (1), pp. 1-93 : 19-20

8. Phyllonorycter maestingella ( Müller, 1764) ( Gracillaridae : Lithocolletinae )

Tinea maestingella Müller, 1764: 58 . Type locality: [ Denmark], [ Frederiksdal ].

BOLD:AAH8496

Palearctic distribution. Widespread in Europe , Russia .

New North American records. Canada: British Columbia, Port Coquitlam (greater Vancouver area ), 22 Jul 2006, at light, 1 ♀ ( CNC) .

Diagnosis. The pattern of forewing markings of maestingella is shared by several species of Phyllonorycter and includes the following elements over an orange-brown ground colour (terms from Emmet et al. 1985): a basal streak (without black edging), four white costal strigulae with anterior black edge, an unedged basal patch, three white dorsal strigulae with anterior black edge, and a black apical spot. Within this general pattern there is variation in details such as the shade of the orange-brown ground colour, extent of black edging of white marks, and black suffusion in the terminal area and terminal fringe. Superficially maestingella is closely similar to restrictella (Braun), and to a lesser extent to some well-known and widespread species such as blancardella (F.), crataegella (Clemens), and mespilella (Hübner). However, the latter three species have the basal streak edged with black, usually on both sides. Examination of genitalia is necessary for positive identification, particularly for worn adults collected on the wing. In male genitalia, the valvae and filaments are symmetrical; the filaments are sigmoid, extended nearly to the apex of the valvae, and with a slim, tapered base about one-fifth the length of valva; the tip of the phallus is pod-like (as opposed to variously hooked in many Phyllonorycter ); and S8 is elongate-conical, apically tapered and rounded. In female genitalia, the sterigma is subcylindrical, about half the length of S8, with a straight, transverse posterior margin, and anteriorly abruptly constricted where it extends into the ductus bursae, the ductus is about 2.5 x the length of S8, the corpus bursae is subspherical, and the signum tiny, double-horned and not surrounded by a weakly sclerotized zone.

Specimens of restrictella are indistinguishable from those of maestingella both externally and possibly also in genitalia: subtle differences in genitalia were observed but their significance could not be assessed, in view of the lack of taxonomic treatment of the Nearctic fauna.

Larval host. Beech ( Fagus spp. , Fagaceae ).

Note. This could be an introduction in North America. However, the species is difficult to recognize based on external characters and is easily confused with several North American species. It could also be an overlooked species that has been present for a long time, especially if confused with restrictella, which also uses Fagus as host plant. The single specimen reported here is quite worn and would have probably remained unrecognized without barcoding. The taxonomy of North American Phyllonorycter is inadequately known. Also it should be noted that there is no native species of Fagus in western North America but species of beeches are planted.

DNA barcodes show two haplotype clusters among European maestingella . The specimen from British Columbia reported here belongs to a haplotype cluster (BOLDAAH8496) with specimens from Belgium, Germany, U.K., Czech, Turkey, Austria, Sweden, and France. All specimens are recorded from Fagus sylvatica except three Turkish specimens reared by Gerfried Deschka from Fagus orientalis . Two additional barcoded specimens from the U.S. (Tennessee) (sample IDs: CLV280711 & CLV280811) match the second European haplotype cluster of maestingella (BOLD: AAL6962). They were reared from Fagus americana and identified by G. Deschka as Phyllonorycter maestingella (Fig. MG8). European specimens in this haplotype cluster are from Austria, Croatia, Finland, France, Italy, Slovenia, U.K. There appears to be no genitalia differences between specimens belonging to the two clusters.

Currently maestingella has six junior synonyms. A detailed morphological analysis as well as study of type material will be needed to assess whether the two haplotype clusters represent different species, and, if they do, which of them represents the “true” P. maestingella , and which name, if any, may apply to the other.

As for restrictella no specimens have been barcoded and its type could not be examined, thus comparisons with maestingella haplotypes and genitalia cannot be made at this time. Given these difficulties and the inadequate state of North American Phyllonorycter taxonomy, we did not pursue the investigation of possible synonymies which would have been beyond the scope of this paper.