Dineura testaceipes ( Klug, 1816 )

Macek, Jan, 2015, Descriptions and key to larvae of Central European Dineura (Hymenoptera: Symphyta: Tenthredinidae), Acta Entomologica Musei Nationalis Pragae 55 (2), pp. 787-796 : 792-793

Dineura testaceipes ( Klug, 1816)

( Figs 2 , 5 , 8 )

Tenthredo (Allantus) testaceipes Klug, 1816: 84 (original description).

Dineura testaceipes: HARTIG (1837: 227) , ENSLIN (1918), TAEGER et al. (1998).

Dineura stilata (misidentification): BRISCHKE (1883), LORENZ & KRAUS (1957), KONTUNIEMI (1960), VERZHUTSKII (1981), PSCHORN- WALCHER & ALTENHOFER (2000).

Material examined. CZECH REPUBLIC: BOHEMIA BOR.: Děčínský Sněžník Mt. (5250), 771 m a.s.l., 26.viii.2010, 2 larvae on Sorbus aucuparia, J. Macek lgt.& det.( NMPC). BOHEMIA CENTR.: Příbram env., Lazec (6349), 21.ix.2002, 8 larvae on Sorbus aucuparia ; Příbram – Hatě (6350), 18.ix.2005, 5 larvae on Sorbus aucuparia ; Příbram env., Květná hill (6250), 5.ix.2009, 5 larvae on Crataegus sp. ; Kokořínsko PLA, Nosálov (5554), 6.ix.2005, 4 larvae on Sorbus aucuparia ; all J. Macek lgt. & det. ( NMPC). BOHEMIA OCC.: Vřesová env., Liščí kopec (hill) (5742), 2.ix.2010, 3 larvae on Sorbus aucuparia, J. Macek lgt. & det. ( NMPC) .

Redescription of the last instar larva. Body length 7–10 mm. Colour. Head green; trunk green with transparent dark gut content; two last annulets of each abdominal segment pale; spiracles white.

Morphology. Head orthognathous with prominent reticulate texture and long slightly curved stiff setae; labrum symmetrical with straight anterior margin; labrum and clypeus with four setae; stipes with one seta; palpifer with two setae.

Trunk dorsoventrally flattened; thorax broader than abdomen; subspiracular lobe of second and third thoracic segment enlarged and prominent with long stiff emarginate and trichoid setae combined; trochanter as long as femur; femur with two setae; tibiae with six setae; abdominal segments with six annulets; the first, second and fourth annulets with long emarginate (in mature larvae), spatulate (in immature larvae) and trichoid setae; the emarginate and spatulate setae occur mostly above the spiracular line and arise from prominent conical warts; setae below spiracular line mostly trichoid; arrangement of setae on annulets above the spiracular line as follows: the 1 st annulet: (2D), (1SD); the 2 nd annulet: (1D), (2SD), (1L); the 4 th annulet: (2D+1G), (2SD), (2L+1G); the postspiracular lobes prominent, the first one with two paired trichoid setae and one glanduba on the conical wart, the second one with two separated trichoid setae; subspiracular lobe prominent, with 5–6 long, slightly curved, trichoid and slightly emarginate setae combined; suprapedal lobe with three trichoid setae and one glanduba; anal segment with long simple stiff setae; prolegs on inner side with two to three short trichoid setae.

Differential diagnosis. Compared to their congenerics, the larvae of D. testaceipes are characteristic in presence of long and slightly emarginate (in last instar) or spatulate (in younger instars) dorsal setae growing up on the prominent conical warts.

Bionomics. Univoltine; flight period from May to July; larval period from July to October. Food plants: Crataegus , Sorbus , Cotoneaster ( BRISCHKE 1883, LORENZ & KRAUS 1957, KON- TUNIEMI 1960, VERZHUTSKII 1981, TAEGER et al. 1998, PSCHORN- WALCHER & ALTENHOFER 2000). Habitat: deciduous and mixed forests, shrubby forest margins, shrubby meadows.

Discussion. The larva of D. stilata described by BRISCHKE (1883) is in fact that of D. testaceipes , a fact pointed out already by ENSLIN (1918) and now also confirmed here. The later descriptions of larvae of D. stilata by LORENZ & KRAUS (1957) and VERZHUTSKII (1981) followed BRISCHKE’ s (1883) interpretation, so that these descriptions can without doubt also be assigned to D. testaceipes . The same is true for the vaguely diagnosed larva of D. testaceipes by LORENZ & KRAUS (1957), which does not differ substantially from their description of the larva of D. stilata . The purpose of the redescription provided here is completeness, so as to make easy the comparison with the descriptions of the larvae of the other Dineura species.

Figures

Figs 1–3. Dineura Dahlbom, 1835, adults: 1 – D. stilata (Klug, 1816), 2 – D. testaceipes (Klug, 1816), 3 – D. virididorsata (Retzius, 1783). Scale bar: 5 mm.

Figs 4–6. Dineura Dahlbom, 1835, larvae (a – lateral view, b – dorsal view): 4 – D. stilata (Klug, 1816), 5 – D. testaceipes (Klug, 1816), 6 – D. virididorsata (Retzius, 1783). Scale bar: 10 mm.

Figs 7–8. Dineura Dahlbom, 1835, 3rd abdominal segment of larvae (a – dorsal section, b – subspiracular lobe): 7 – D. stilata (Klug, 1816), 8 – D. testaceipes (Klug, 1816), 9 – D.virididorsata (Retzius, 1783). Scale bar: 0.05 mm.