Eutomostethus ephippium (Panzer, 1798)

Macek, Jan, 2014, Descriptions of larvae of the Central European Eutomostethus species (Hymenoptera: Symphyta: Tenthredinidae), Acta Entomologica Musei Nationalis Pragae 54 (2), pp. 685-692 : 686

Eutomostethus ephippium (Panzer, 1798)

( Figs 1 , 6 )

Material examined. CZECH REPUBLIC: BOHEMIA CENTR.: Pravonín env., ýástrovice (6355), 27.vii.2010, larvae on Poa sp .; J. Macek lgt. & det. ( NMPC) .

Description of the last instar larva. Body length 9–10 mm. Head amber yellow with nebulose blackish stripe alongside coronal suture, head surface granulose, in upper half with scattered tiny setae, and a row of longer setae alongside the epistomal suture; clypeus with six setae; labrum symmetrical, deeply emarginated, with eight setae; mandibles with one seta, palpifer with three setae, maxillar palpus with one seta, stipes with one seta; body slender, slightly tapered caudally; upper parts of body grey-yellowish, lower parts whitish with dark, nebulous, dorsal and supraspiracular longitudinal stripes and intermittent black spot above each spiracle; cuticle ¿nely granulose; trochanter as long as femur, with scattered long hair-like setae, third abdominal segment with six annulets; second and fourth annulets, subspiracular and surpedal lobes, and anal segment with several tiny cylindrical setae; all conical setae (= glandubae) missing.

Notes on identification. The larvae of Eutomostethus ephippium differ from those of other Eutomostethus species in black spots above the spiracles and in the absence of glandubae on the annulets.

Bionomics. Habitat: mesophile and humid meadows, pastures, humid grasslands, alluvial meadows, grassy forest margins; probably polyvoltine; flight period May to September, larval period May to October; host plants: Poa spp. and other soft grasses ( CONDE 1934; this paper). Discussion. The development with the description of larvae is given by CONDE (1934) and some additional characters are given by LORENZ & KRAUS (1957). The redescription is provided here for completeness, to facilitate its comparison with those of the larvae of the other Eutomostethus species. Compared to their congenerics, the larvae of E. ephippium are unique in the absence of glandubae on the annulets, and in their association with soft grasses ( Poaceae ). In contrast, larvae of E. luteiventris , E. gagathinus and E. punctatus possess glandubae and they are associated with rushes ( Juncus ) and sedges ( Carex ).

Figures

Figs 1–4. Mounted larvae from alcohol. 1 – Eutomostethus ephippium (Panzer, 1798); 2 – E. luteiventris (Klug, 1816); 3 – E. punctatus (Konow, 1887); 4 – E. gagathinus (Klug, 1816). Lettering: a – the cuticular sculpture of the anal segement; b – the prothorax, the arrow indicating the protuberant suprapedal lobe. Scale bar: 2 mm.

Figs 5–8. Living last instar larvae (a – lateral view; b – dorsal view). 5 – Eutomostethus gagathinus (Klug, 1816); 6 – E. ephippium (Panzer, 1798); 7 – E. punctatus (Konow, 1887); 8 – E. luteiventris (Klug, 1816). Scale bar: 5 mm.