Camptomyia oldhammeri, Jaschhof & Jaschhof, 2019

Jaschhof, Mathias & Jaschhof, Catrin, 2019, New and rarely found species of asynaptine Porricondylinae (Diptera: Cecidomyiidae) in northern Europe, Zootaxa 4604 (2), pp. 281-300 : 290-291

Camptomyia oldhammeri sp. nov.

Figs 10–12

Our previous view that Asynaptini including Camptomyia have only inconspicuous structures on the gonostylar apex, typically small brushes or combs of fine spines ( Jaschhof & Jaschhof 2013), must be revised with the discovery of C. oldhammeri , a species whose gonostylus bears a solid tooth of enormous size. This peculiarity makes it difficult to establish a relation of C. oldhammeri to any of the congeneric species in Europe and beyond.

Diagnosis. The gonostylus of C. oldhammeri is unique in that its thick, compact base transitions into two branches, of which the ventral is an elongate, setae-bearing lobe ( Fig. 10 , ↓ 1) and the dorsal is an extremely large, recurved tooth (↓ 2). Such a complex construction is in marked contrast to the simplicity of the copulatory organ, which consists of the long, thin aedeagus, flanked by a single pair of almost straight, needle-like parameres ( Fig. 10 , ↓ 3). Females and preimaginal stages of C. oldhammeri are unknown.

Other male characters. Body size 2.9 mm. Head. Eye bridge 8–9 ommatidia long dorsally. Scape and pedicel concolorous with flagellum. Flagellomeres 19. Neck of fourth flagellomere slightly shorter than node ( Fig. 12 ). Palpus with 4 segments, slightly longer than head height. Wing as long as body, 2.6 times longer than wide.

Legs. Claws with single large tooth basally. Empodia broad, two thirds as long as claws. Genitalia. Ninth tergum faintly contoured, the vestigial sclerite consisting of a posterior, semicircular area with a few setae and a distinct apodeme running all along the longitudinal axis; posterior edge with small, U-shaped indentation medially ( Fig. 11 ). Gonocoxal synsclerite broader than long, with dense setae of various sizes; ventral bridge non-setose; ventral emargination deep, subrectangular, without lobe anteriorly; dorsal apodemes longer than the distance separating them ( Fig. 10 ). Aedeagus including apodeme 1.5 times as long as parameres; base simple, not T-shaped; apex slightly narrowed. Apices of aedeagus and parameres on almost same level; parameral apodemes somewhat enlarged, wingshaped ( Fig. 10 ).

Etymology. In naming this new species after Bengt Oldhammer, living in Orsa, we honor an outstanding natu- ralist and dedicated conservationist, who has left his mark in the natural history of Dalarna through his countless inventories of threatened biodiversity in Sweden’s forest heartland, and his informed proposals for how these natural resources can be safeguarded. One of Bengt’s latest projects, the assessment of the worthiness of protection of the Unnån valley, included validation of the stretch of alluvial forest where the only specimen known of C. oldhammeri was collected (see the notes below).

Type material. Holotype. Male, Sweden, Dalarna, Unnån valley, Långfloten , 8 km SE Näckådalen, swampy natural forest of birch, spruce and pine, 1–20 July 2018, Malaise trap, M. & C. Jaschhof (spn. no. CEC 1752 in NHRS).

Notes on the type locality. Långfloten is a stretch of natural, boreal forest characteristic of the Unnån valley: marked by a botanically rich mosaic of vegetation types within a small area, including old-growth forest with plenty of dead wood, reshaped annually by strongly varying water levels and ice flows of the river Unnån, and proven to provide habitat for threatened and red-listed species in various taxonomic groups ( Turander et al. 2018). The peculiar character of this alluvial forest was the reason to make it one of the Malaise trap sites of our 2018 collecting campaign in west-central Sweden. Regrettably, the season was overshadowed by a large-scale hot spell and drought during the main flight period of porricondyline midges. One might argue that the discovery of C. oldhammeri , an obviously rare and morphologically highly unusual species, in an extraordinary habitat like Långfloten is correlative rather than random, but in the absence of detailed biological information on the new gall midge this is merely speculation. A more extensive survey of mycophagous gall midges in the Unnån valley, including Långfloten, is in preparation.

Figures

FIGURES 10–15. Morphology of Camptomyia spp. 10–12: C. oldhammeri, holotype; 13–15: C. rhynchostylata, holo- and paratype. 10: Genitalia, ventral. 11: Ninth tergite, dorsal. 12: Fourth flagellomere, lateral. 13: Fourth flagellomere, lateral, paratype. 14: Genitalia, ventral, holotype. 15: Aedeagus and parameres, ventral, holotype. Scales 0.05 mm. Arrows refer to characters described in the diagnoses.