Megabeleses magnoliae, Wei, Meicai, 2010

Wei, Meicai, 2010, Revision of Megabeleses Takeuchi (Hymenoptera, Tenthredinidae) with description of two new species from China, Zootaxa 2729, pp. 36-50 : 40-41

Megabeleses magnoliae sp. nov.

( Figs. 8–11 , 41–42, 44, 50 )

Megabeleses crassitarsis: Ding & Zheng (1999) , misidentification.

Description. Holotype: Ƥ.

Body length 10–11 mm ( Fig. 8 ). Black, without metallic blue tinge; labrum, broad posterior margin of pronotum, tegula, posttergite, posterior 3/4 of 1st abdominal tergite, outer side largely and apex of hind coxa, hind trochanter, 2nd trochanters of fore and middle legs, basal half of hind femur, yellow white; palpi dirty brown, posterior margin of 10th abdominal tergite, cerci, apical 3/5 of anterior side, apical 1/3 of posterior side and entire dorsal side of fore femur, apical 1/5 of and base of middle femur, fore and middle tibiae and tarsi, hind tibia except apex, hind tarsus entirely yellow brown. Wings hyaline with feeble yellowish tinge, basal half of vein C and of 1A pale brown, stigma and other veins black brown. Body hairs silver brown, setae on sheath brown.

Frons, inner orbits, clypeus and posterior orbits densely, temple and postocellar area sparsely punctured; lateral lobe of pronotum, anterior half of prescutum mesoscutellum entirely and posttergite coarsely punctured, other part of pronotum, posterior half of prescutum sparsely punctured, scutum evenly punctured; elevated part of metathorax near cenchri coarsely, metascutellum densely punctured, parapsis microsculptured; upper half of mesepisternum and upper margin of mesepimeron coarsely punctured without shining interspace, ventral half of mesepisternum and of metepisternum very sparsely punctured, strongly shining, other part of mesepimeron coriaceous, dorsal margin of metepisternum and of metepimeron coarsely punctured; outer side of hind coxa densely punctured on basal half, apical half sparsely punctured. Abdominal tergites impunctate, distinctly microsculptured; lateral sides of ovipositor sheath polished, shiny.

Anterior margin of clypeus almost truncate, with 4–6 obscure and small teeth; malar space as long as radius of ocellus; closest distance between eyes 1.33× height of eye; distance between antennal sockets 0.8× distance between antennal socket and eye; middle fovea round; circular furrow of anterior ocellus, postocellar and interocellar furrows obscure; postocellar area flat, 1.2× broader than long, without middle furrow; lateral furrows broad, very shallow, divergent backwards; lateral margins of head behind eyes in dorsal view about half length of eye, hardly narrowed, subparallel. Antenna much longer than abdomen, slightly shorter than thorax and abdomen together, third antennomere 1.1× longer than fourth antennomere. Mesoscutellum slightly broader than long, anterior corner roundly protruding, obtuse; posterior margin shorter than anterior margin ( Fig. 41 ), highly carinate ( Fig. 42 ); posttergite without middle carina, apical margin round; distance between cenchri 1.8× width of a cenchrus; dorsal lobe of metepimeron long and narrow ( Fig. 44 ). Length of inner margin of 1st abdominal tergite 1/3 length of widest lateral length. Apex of hind coxa reaching middle of 4th sternite, outer side of hind tibia with distinct longitudinal furrow, apex distinctly thickened; inner spur of hind tibia 0.35× length of hind basitarsus; hind basitarsus 4.5× as long as broad, weakly thickened with constricted base, as long as following 4 tarsomeres together, outer side with a distinct furrow. Vein cu-a meeting cell 1M at basal 1/7, R+M punctiform, 2r weakly bent and meeting cell 2Rs at apical 3/7, 2m-cu not interstitial to 1r-m; petiole of hind anal cell about half length of cu-a. Ovipositor sheath 0.84× length of middle tibia, sheath 1.4× longer than basal plate, apical margin oblique in lateral view; apical sheath in dorsal view triangular, basal width 2× width of cercus; setae on lateral sides of apical sheath as long as diameter of ocellus. Lancet with 25 serrulae, middle serrulae each with about 20–25 indistinct subbasal teeth ( Fig. 50 ); membranous lobe of lance slightly narrower than width of lance at middle.

Male: Body length 9–10 mm ( Fig. 9 ). Colour and structure similar to female, except for: closest distance between eyes 1.1× broader than height of eye, head behind eyes distinctly narrowed in dorsal view; vein 2m-cu interstitial to 1r-m; subgenital plate as long as broad, apical margin obtusely truncate; harpe broader than long, apical margin oblique ( Fig. 10 ); penis valve broad, apex with a deep dorsal incision ( Fig. 11 ).

Distribution. China (Anhui) ( Fig. 51 ).

Variation. The height of the posterior carina of mesoscutellum is not constant, about 0.4–1.3× diameter of an ocellus.

Etymology. This new species is named after the generic name of the host plant.

Specimens examined. Holotype: Ƥ, Mt. Dabieshan, Huoshan, Anhui Province, April 1992, Yuzhou Ding. Paratypes: 1Ƥ33, Mt. Dabieshan, Huoshan, Anhui Province, April 1992, Yuzhou Ding (Holotype and paratypes were reared from larvae feeding on Magnolia denudata Desr. ) (CSCS).

Host plants. Magnolia denudata Desr. and Magnolia liliflora Desr. ( Ding & Zheng 1999 under the name M. crassitarsis ).

Biology. M. magnoliae feeds on leaves of M. denudata Desr. and M. liliflora in Mt. Dabieshan above alt. 500 m. One generation occurs per year. Adults have been found from mid March to the end of April. Larvae aggregate on leaves and damage the plants from the end of April to the beginning of June, and overwinter below a tree as prepupae in soil at depths of up to 10 cm. See Ding & Zheng (1999) for details of the biology of the species.

Remarks. Ding & Zheng (1999) reported the present species under the name M. crassitarsis from China. Actually, M. crassitarsis is restricted to Japan, and M. crassitarsis auct. from China is a separate species described here as M. magnoliae .

Figures

FIGURE 51. Distribution records of Megabeleses spp.

FIGURES 8 – 11. Megabeleses magnoliae, sp. nov. 8. Adult, female; 9. Adult, male; 10. Harpe; 11. Penis valve.

FIGURES 39 – 50. Megabeleses spp. 39 – 41. Mesoscutellum and posttergite, dorsal view; 42. Mesoscutellum and posttergite, lateral view; 43 – 46. Metepimeron; 47 – 50. 10 th serrula. 39, 43, 49, M. xiaoi; 41, 42, 44, 50, M. magnoliae; 40, 45, 48, M. liriodendrovorax; 46, 47, M. crassitarsis.