Proterops borneoensis Szépligeti, 1902

Achterberg, C. van & Chenon, R. Desmier de, 2009, The first report of the biology of Proterops borneoensis Szépligeti (Hymenoptera: Braconidae: Ichneutinae), with the description of a new species from China, Journal of Natural History 43 (11 - 12), pp. 619-633 : 627-629

Proterops borneoensis Szépligeti, 1902

( Figures 2H , 4 A–C, 5G)

Proterops borneoensis Szépligeti, 1902, p. 80 ; Shenefelt, 1973, p. 811. Morphology

Very similar to P. nigripennis Wesmael. Differs by the more transverse second tergite ( Figure 4C ), the lack of a narrow ventral rim of the clypeus, the blackish or black setae of the propodeum and the distinctly sinuate vein 2-SR of the forewing (as usually vein 1-SR+M; Figure 4A ). The holotype (not lectotype since Szépligeti obviously had only one specimen in 1902) has the propodeal setae brownish, but the whole specimen is rather bleached and the setae are likely to have been darker originally. The legs are dark brown, but the hind coxa, trochanter and trochantellus and the basal half of the hind femur are yellowish. The clypeus and the face ventrally are brown. Vein 2-SR of forewing of the holotype is strongly curved posteriorly (not vein m-cu as mentioned in the description!), vein 1-SR+M of the forewing has a short appendage and the lower tooth of the mandible is distinctly shorter than the convex upper tooth.

Variation

The number of hamuli of the hind wing is variable: usually four in females, but three and rarely five occur, and usually three to four in males, with rarely with only two hamuli; vein cu-a of forewing is normally postfurcal by 0.2–0.3 times its length, but sometimes by 0.4–0.5 times; hind coxa, trochanter, trochantellus and femur more or less darkened dorsally; sometimes vein r of hind wing and appendices of veins 2-SR or 1-SR+M of forewing present.

Distribution

Indonesia [Borneo (holotype), Sumatra (this paper)]; Nepal (ibid.). The host occurs also in Nepal, which explains the occurrence of the same parasitoid in Nepal. Nothing is known or reported regarding C. janthina in the Malaysian Peninsula, Thailand, Vietnam and Laos, although R. alceifolius is present and C. janthina is known from Singapore. The host of P. borneoensis may be present from the Sunda area up to the north of India and Nepal as well as in the mountains of southern China because it has been reported from Taiwan. In southern China Cibdela chinensis Rohwer, 1921 also occurs, which may be an alternative host for Proterops species in China.

We have collected P. borneoensis in north Sumatra at 369 m (Pematang Siantar Marihat) to 914 m at Samosir Island situated in the middle of the Toba Lake (2 ° 4097080 N, 98 ° 5190980 E). On the northern border of the lake at Simarjarunjung, R. alceifolius is found up to 1227 m. We released 1000 larvae of C. janthina at 1147 m (2 ° 4392430 N, 98 ° 5499700 E) to establish a population of this sawfly on Rubus , but the effort was in vain. In conclusion, C. janthina and P. borneoensis are present only on the border of the lake where specifically warmer microclimatic conditions are present. Above 1227 m R. alceifolius is replaced by other Rubus species. Rubus moluccanus L. occurs together with C. janthina below 300 m but apparently without the presence of the parasitoid of the latter. The second author has found and collected C. janthina in Singapore at Bukit Timah near sea level, but has never observed it with Proterops flying during many observations at different periods of the year. The braconid was also not obtained from the collected material. In summary, in Sumatra P. borneoensis is found only between 369 and 914 m altitude, if there is C. janthina feeding mostly or only on R. alceifolius in the mountains of the Bukit Barisan.

Material

Holotype female, ‘‘ Indonesia, Borneo’’, ‘‘ borneoensis det. Szépligeti’’, ‘‘ Lectotype $ Proterops borneoensis sp. nov. Szépl., 1902/des. Papp J, 1967’’, ‘‘Hym. Typ. No. 760 Museum Budapest’’ (MTMA); 52 females plus 143 males from Indonesia, Sumatra, Siantar, Marihat Experimental Research Station, ex C. janthina (Klug) (Argidae) feeding on R. alceifolius Poir. , summer 2005, R. Desmier de Chenon (RMNH, MTMA); one male, Nepal, Pokhara (RMNH).

Figures

Figure 2. (A–G) Cibdela janthina (Klug), Indonesia, Sumatra, Pematang Siantar. (A) Adult female of C. janthina searching for oviposition. (B) Ibid, but ovipositing in leaf vein. (C) Eggs of C. janthina in leaf veins. (D) Second instar larvae. (E) Fourth instar larvae. (F) Fourth instar larvae in typical feeding position. (G) Defoliation damage by larvae of C. janthina. (H) Proterops borneoensis Szépligeti, ibid. (H) Adult female of P. borneoensis.

Figure 4. Proterops borneoensis Szépligeti, female, Indonesia, Sumatra, Pematang Siantar. (A) Apical part of fore wing. (B) Anterior subalar depression. (C) First to third metasomal tergites, dorsal aspect. Scale bars 1.0X(A); 1.3X(B); 2.3X(C).