Aptesis melana Li & Sheng

Li, Tao, Sheng, Mao-Ling & Sun, Shu-Ping, 2013, Chinese species of the genus Aptesis Foerster (Hymenoptera, Ichneumonidae) parasitizing sawflies, with descriptions of three new species and a key to species, ZooKeys 290, pp. 55-73 : 60-64

Aptesis melana Li & Sheng sp. n. Figures 10−18

Etymology.

The name of the new species is based on the black body color.

Types.

Holotype, female, CHINA: Weining County, Guizhou Province, 20 February 2012, leg. Mao-Ling Sheng. Paratypes: 2 females, CHINA: Jialing River, Shaanxi Province, 8 May 2010, 2025m, leg. Tao Li; 2 females, CHINA: Pingheliang, Shaanxi Province, 16 to 24 May 2010, leg. Tao Li; 6 females, CHINA: Maiji Mountains, Gansu Province, 8 to 24 May 2010, leg. Tao Li; 35 females and 15 males, CHINA: Liupan Mountains, Ningxia Hui Autonomous Region, 8 May to 1 August 2011, leg. Tao Li; 337 females and 199 males, CHINA: Weining County, Guizhou Province, 17 February to 3 April 2012, leg. Tao Li, Mao-Ling Sheng; 11 females and 5 males, CHINA: Liupan Mountains, Ningxia Hui Autonomous Region, 17 to 23 May 2012, leg. Tao Li. All specimens reared from Pristiphora erichsonii in Jialingjiang River, Pingheliang, Maiji Mountains and Liupan Mountains, except one reared from Neodiprion huizeensis in Weining County, Guizhou Province.

Diagnosis.

Clypeus approximately 1.7 times as wide as long. Mandible teeth about equal in length. Malar space approximately 1.4 times as long as basal width of mandible. Postocellar line approximately 1.4 times as long as ocular-ocellar line. Antenna with 25 flagellomeres. Fore wing with vein 1cu-a opposite 1/M; Vein 2-Cu approximately 1.5 times as long as 2cu-a. First tergum about 1.3 times as long as apical width. Ovipositor sheath about 0.8 times as long as hind tibia.

Description.

Female (Fig. 10). Body length 6.0 to 9.0 mm. Fore wing length 5.0 to 7.0 mm.

Head. Face (Fig. 11) about 2.7 times as wide as long, with dense fine punctures; centrally convex, punctures smaller than on remainder of face; upper margin concave. Clypeus approximately 1.7 times as wide as long; basally with dense fine punctures; apically with weak wrinkles; apical margin flat. Mandible with dense punctures, teeth approximately equal in length. Malar space with fine leathery texture, approximately 1.4 times as long as basal width of mandible. Gena (Fig. 12) with evenly dense punctures. Vertex (Fig. 13) with texture as gena. Outside of ocellar triangle with sparse punctures. Postocellar line approximately 1.4 times as long as ocular-ocellar line. Frons with evenly dense punctures, basally smooth. Antenna with 25 flagellomeres, ratio of length from first to fifth flagellomeres: 12.0:11.0:10.0:9.0:7.0. Occipital carina complete.

Mesosoma. Pronotum anteriorly with weak wrinkles; medially with short transverse wrinkles; with dense punctures dorso-posteriorly. Mesoscutum (Fig. 14) flat, with dense punctures. Notaulus present anteriorly. Scutellum with punctures sparser than on mesoscutum. Postscutellum transverse, smooth. Mesopleuron (Fig. 15) with texture as mesoscutum, with irregular wrinkles. Epicnemial carina strong, reaching subalar ridge. Sternaulus distinct, reaching hind margin of mesopleuron, apically ventral to ventral-posterior corner of mesopleuron. Scrobe with strong groove. Metapleuron with texture as mesopleuron. Juxtacoxal carina incomplete. Submetapleural carina complete. Legs robust. Ratio of length of hind tarsomeres 1:2:3:4:5 is 13.0:5.0:4.0:2.0:4.0. Fore wing (Fig. 18) with vein 1cu-a opposite 1/M. Vein 3rs-m anteriorly convergent with 2rs-m. Areolet receiving vein 2m-cu approximately at its middle. Vein 2-Cu approximately 1.5 times as long as 2cu-a. Hind wing vein 1-cu about 4.0 times as long as cu-a. Propodeum (Fig. 16) weakly convex. Anterior transverse carina absent. Areas basalis and superomedia combined, with irregular wrinkles. Areas externa and dentipara combined; basal portion with sparse punctures and weak wrinkles; apically with irregular short wrinkles. Posterior transverse carina strong. Area petiolaris sloping, with irregular wrinkles; medially weakly concave. Propodeal apophysis distinct. Propodeal spiracle approximately circular, located at anterior 0.2 of propodeum.

Metasoma (Fig. 17). First tergum about 1.3 times as long as apical width, apically with weak wrinkles. Median dorsal carinae distinct, basally parallel. Dorsolateral and ventrolateral carinae complete. Spiracle circular, small, located at apical 0.3 of first tergum. Second tergum approximately 0.5 times as long as apical width, smooth. Third to eighth terga with texture as second tergum. Ovipositor sheath about 0.8 times as long as hind tibia. Ovipositor strong, straight, apically sharp. Apical portion of lower valve with 2 ridges.

Color (Fig. 10). Black, except the following. Sixth to ninth (base of tenth) flagellomeres, wing base, yellowish white. Apical portion of clypeus, mandible (basally and teeth, blackish brown), fore leg (part of coxa black; first trochanter, femur laterally, blackish brown), mid leg (coxa, femur, blackish brown), hind leg (coxa, femur, tibia apically, first tarsomere, blackish brown), reddish brown. Maxillary and labial palpi, pterostigma, veins, blackish brown. Wing membrane brownish hyaline.

Male. Body length 7.0 to 8.0 mm. Fore wing length 5.0 to 7.0 mm. Body black. Face, clypeus, mandible (teeth black), maxillary and labial palpi, wing base, yellowish white. Fore leg (most of coxa, trochanters, second to forth tarsomeres, yellowish white; fifth tarsomere brown), mid leg (part of coxa, trochanters, second to fourth tarsomeres, yellowish white; most of femur blackish brown; most of first and fifth tarsomeres, brown), hind leg (coxa, trochanters, femur, most of tibia, blackish brown; first and fifth tarsomeres basally brown; Apex of first and second to fourth tarsomeres, yellowish white), reddish brown.

Hosts.

Neodiprion huizeensis ( Hymenoptera : Diprionidae ), Pristiphora erichsonii ( Hymenoptera : Tenthredinidae ).

Host plants.

Pinus armandi , Larix principis -rupprechtii ( Pinaceae ).

Biology.

The mature larva of Aptesis melana forms a cocoon outside the body of the Neodiprion huizeensis larva and inside the cocoon of the host. The mature larva of Aptesis melana is cream-colored (Fig. 19). The pupa changes continuously as development continues. The young pupa is cream-colored, the compound eyes light red. After three days, the compound eyes change to dark red (Fig. 20). Two days later, the head and mesosoma are blackish brown (Fig. 21). After two days, the head and mesosoma change to black; the first and second terga blackish brown, third to eighth terga brown (Fig. 22); the basal portion of flagellomeres brown, median portion yellowish white and apical portion yellowish brown. The mature pupa is the same color as the adult. Of 537 Aptesis melana reared from Neodiprion huizeensis , the female to male ratio was 1.7: 1. The average parasitism rate of Neodiprion huizeensis by Aptesis melana was 8.7%. Adults of Aptesis melana emerged between 17th February to 12th March under laboratory conditions.

Remarks.

This new species is similar to Aptesis albibasalis (Uchida, 1930) but can be distinguished from the latter by the following combination of characters: malar space about 1.4 times as long as basal width of mandible; postocellar line about 1.4 times as long as ocular-ocellar line; first tergum about 1.3 times as long as apical width; hind tibia basally dark reddish brown. Aptesis albibasalis : malar space about 0.9 times as long as basal width of mandible; postocellar line about equal with ocular-ocellar line; first tergum about 1.7 times as long as apical width; hind tibia basally white.