Lonchodryinus ruficornis ( Dalman, 1818 )

Bückle, Christoph, 2017, Larval morphology of three species of Anteoninae (Hymenoptera, Dryinidae), Zootaxa 4320 (3), pp. 470-486 : 478-484

Lonchodryinus ruficornis ( Dalman, 1818)

Figs 9–15

Material examined. Italy, L’Aquila Province, Campo Imperatore, 1800 m, 5.VI.2016, 5 immature and 10 mature larvae parasitizing Diplocolenus bohemani (Zetterstedt, 1840) , D. nigrifrons (Kirschbaum, 1868) and Psammotettix helvolus (Kirschbaum, 1868) (Cicadellidae) feeding on Poaceae .

Description, immature larva. Main characters ( Figs 9B, 9C , 10A–10F , 11A, 11B , 12A ) as in Anteon flavicorne (see above). Frontal area of cephalic region without cephalic vesicles. “Mask” covering the cephalic region with a pair of rounded slightly convex strongly sclerotized areas in correspondence to the frontolateral angles of the head capsule. Body in lateral view rounded, slightly oblong ( Fig. 9C ).

Remarks. All the immature larvae observed were protruding from the host between pro- and mesothorax ( Fig. 9A ). The main difference to the immature larva of Anteon flavicorne lays in the different structure of the “mask” covering the cephalic region ( Figs 2A, 2B , 7A, 7B , 10 , 11 ).

Description, mature larva. Body length: ca. 2.2–3.2 mm. Chaetotaxy, shape of mouthparts and antennae ( Figs 9D, 9E , 12B–12F , 13A–13F , 14A–14F ) as in Anteon flavicorne . In particular, the following characters may be emphasized: labrum with apical row of six to eight sensory bristles inserted immediately under its apical margin ( Figs 12B , 13C ); epipharynx with two sensilla near anterior margin ( Fig. 13F , arrows); labium triangular, spinneret narrow ( Figs 14A, 14B, 14E, 14F ); thorax and abdomen with numerous long bristles (ca. 160 µm) arranged in transverse rows around each segment; thoracic spiracles and abdominal ones approximately of the same size; atrium of spiracles bulb-shaped. All spiracles simple, without bristles, hairs or other particular protective structures.

Remarks. Cocoon in the ground, covered by small soil particles; in laboratory conditions the larva built its cocoon on the vial wall ( Figs 15A–15D ).

Figures

FIGURE 2. Anteon flavicorne (Dalman). A, B. Immature larva. A. Anterior region, frontal view. B. Anterior region, lateral view (ap = “ anneau péricéphalique ” sensu Buyckx, 1948). — C. Mature larva, lateral view.

FIGURE 7. Anteon flavicorne (Dalman). A, B. Immature larva with “ mask ”. A. Anterior region, frontal view. B. Anterior region, lateral view. C – F. Mature larva, head. C. Frontal view (arrows: two sensilla of the epipharynx). D. Dorsal view. E. Lateral view. F. Ventrofrontal view.

FIGURE 9. Lonchodryinus ruficornis (Dalman). A – C. Immature larva. A. On Diplocolenus bohemani (Zetterstedt), in position between pro- and mesothorax. B, C. Lateral view. D, E. Mature larva. D. Dorsal view. E. Lateral view.

FIGURE 10. Lonchodryinus ruficornis (Dalman). Immature larva. A – C. Anterior region, frontolateral view. D – F. Anterior region, lateral view (ap = “ anneau péricéphalique ” sensu Buyckx, 1948).

FIGURE 11. Lonchodryinus ruficornis (Dalman). Immature larva, anterior region. A. Frontal view. B. Frontoventral view.

FIGURE 12. Lonchodryinus ruficornis (Dalman). A. Immature larva, lateral view. B – F. Mature larva. B. Labrum. C. Left mandible, dorsal view. D. Labium and left maxilla, ventral view. E. Right maxillary palp, ventral view. F. Left labial palp, ventral view.

FIGURE 13. Lonchodryinus ruficornis (Dalman). Mature larva. A. Head, ventral view. B. Clypeus and labrum. C. Epipharynx. D. Left maxillary palp, ventral view. E. Antenna. F. Epipharynx (arrows: two sensilla, right one lost, but base still visible).

FIGURE 14. Lonchodryinus ruficornis (Dalman). Mature larva. A. Head, ventrofrontal view. B. Head, frontal view. C. Labrum and epipharynx, frontal view. D. Labium, ventral view. E. Labium, ventrolateral view. F. Labium, ventrofrontal view.

FIGURE 15. Lonchodryinus ruficornis (Dalman). A – D. Mature larva building its cocoon on the vial wall.