Blastobasis glandulella ( Riley, 1871 )

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 : 26

14. Blastobasis glandulella ( Riley, 1871) ( Blastobasidae : Blastobasinae)

Gelechia glandulella Riley, 1871: 118 . Type locality: USA: Missouri.

= Blastobasis huemeri Sinev, 1993: 369 . Type locality: Croatia: Krk Island . New synonymy.

BOLD:AAB1096

Palearctic records. Central Europe , including Austria, Croatia, Czech Republic, France, Germany, Hungary, Italy, Slovakia , and Switzerland.

Nearctic distribution. Widespread in the East from Québec and Ontario south to Florida, west to Colorado east of the Rocky Mountains , Arizona, and as far south as Brownsville, Texas; probably occurs also in northern Mexico (D. Adamski, pers. comm.). In Canada known only from Québec, Ontario, and Manitoba ( CNC) .

Diagnosis. This species is highly variable in size and forewing colouration. Among the North American specimens barcoded, forewing span varies from 12–25 mm, seemingly irrespective of sex. Most specimens are grey with a darker grey chevron-shaped transverse band in the basal third of the forewing inwardly lined with a paler, variously contrasting band (as shown in Fig. 14); in some specimens the dark band is nearly black and the distal third beyond it is more contrastingly very pale grey. Many specimens have one or two dark dots in the distal third of the forewing. There is enough variation in external appearance of the moths to give the impression that there could be more than one species. Genitalia must be examined for positive identification. In male genitalia, the uncus is conical, the gnathos has the medial process bifid and wide lateral arms, the cucullar lobe of the valva is evenly digitiform, the saccular lobe is very slightly upcurved and extended to, but not exceeding, the apex of the cucullus, the base of the dorsal margin of the valva is thickened to about one-third the width of the valva, and the proximal flange is wide, half the width of the valva with a rounded ventral expansion covered with a zone of dense microtrichia mesially and coarse spinules posteriorly. In female genitalia, the ovipositor is about 1.5 x the length of S1-S7, the S7-S8 intersegmental membrane is longer than S7 and laterally covered with dense, coarse microtrichia in the basal two-thirds which gradually thin out in the posterior third, the anterior half of the ductus bursae is finely spinulate and with one loop, and the corpus bursae has a lateral lobe near the inception of the ductus bursae and a thorn-like signum. Other species of Blastobasis show variation and differences in all these aspects. However, the lack of revision of the Nearctic species makes it difficult to present a more comparative diagnosis.

Larval host. Various acorns ( Quercus ) and chestnuts ( Castanea ) ( Fagaceae ).

Note. This native North American species was first found in Croatia in the 1980s and has since spread to much of temperate Central Europe showing the typical pattern of an invasive species.