Cremastobaeus nigricephalus Veenakumari, 2017

Kamalanathan, Veenakumari & Mohanraj, Prashanth, 2017, The genus Cremastobaeus Ashmead (Hymenoptera: Scelionidae: Cremastobaeini) from India, Journal of Natural History 51 (33 - 34), pp. 1989-2056 : 2023-2025

Cremastobaeus nigricephalus Veenakumari sp. nov.

( Figure 16 (a–h))

www.zoobank.org/ urn:lsid:zoobank.org:act:072E3AFF-31E4-404B-B904-25BB58BBF335

Holotype: Female. Body length = 1.59 mm; (m = 1.55 (1.51–1.59) mm, SD = 0.06, n = 2)

Colour ( Figure 16 (a))

Head black; mesosoma red-brown with a weak dark brown patch medially; pleuron orange-yellow; metasoma brown, with posterior tergites black-brown; A1–A4 yellow, except A2–A4 with a tinge of red; A5–A7 yellow-brown with black patches, A8 and clava grey-brown; mandibles red-brown; legs yellow.

Head ( Figure 16 (b,c,f))

FCI = 1.34; LCI = 1.02; IOS 0.43× width of head; POL>LOL in ratio of 9.5:5.1, lateral ocellus contiguous with orbit; eye large (L:W = 13.8:14.3); frontal depression with both short and long transverse weak striae; vertex and gena coriaceous reticulate; length and width of antennomeres A1–A 8 in ratio of 15.9:3.8, 5.9:4.3, 6.3:3.9, 4.1:3.0, 4.9:3.2, 4.4:3.2, 3.0:4.0, respectively; length and width of clava 14.5:7.7; radicle 0.19× as long as A1.

Mesosoma ( Figure 16 (c,d,e,h))

Mesoscutum (L:W = 22.5:25.0) coriaceous reticulate and setose; lateral pronotal area unevenly sculptured with sparse striae ventrally; netrion smooth, foveae on anterior margin not distinct; prespecular sulcus foveate dorsally, foveae not distinct; speculum with several transverse striae; mesepimeral sulcus very weakly foveate, foveae not distinct; mesopleural depression and ventral mesopleuron smooth; metapleuron smooth above transverse metapleural sulcus; metapleuron beneath transverse metapleural sulcus very weakly striate in ventral half; foveae of paracoxal sulcus not distinct; scutoscutellar sulcus medially evenly narrow throughout; mesoscutellum (L:W = 9.0:17.4) rectangular, coriaceous reticulate, setose; posterior mesoscutellar sulcus foveate with a smooth band beneath; metascutellum (L:W = 3.3:10.3), rectangular, coriaceous reticulate in anterior half and almost smooth in latter half with four vertical striae; propodeum broadly medially excavate; lateral propodeal area rugose without foveae on ventral margin; fore wing (L:W = 93.7:31.7) and hind wing (L:W = 77.3:11.3) hyaline with dense microtrichia; length of marginal cilia of fore wing and hind wing 0.08× and 0.33× width of their wings, respectively; length of submarginalis: marginalis: stigmalis: postmarginalis in ratio of 38.4:8.0:10.1:25.5, respectively.

Metasoma ( Figure 16 (g))

(L:W = 91.6:25.6); anterior margin of T1 not visible when viewed dorsally; entire T1 costate except for a small smooth patch postero-medially; a short horn present antero-

medially on T1; horn anteriorly smooth with costae on posterior two-thirds; T2 with basal foveae, costate the entire length; T3–T5 with reticulations on anterior margin, remainder costate; T6 reticulate in anterior half, remainder smooth; length and width of tergites T1–T 7 in ratio of 20.6:15.8, 14.1:22.6, 14.1:26.4, 12.7:24.5, 12.9:20.9, 10.8:15.7, 6.3:5.5, respectively; T1 longest of all tergites, T2–T3 subequal.

Variation

The paratype is a variant with a darker mesosoma.

Male

Unknown.

Material examined

Holotype: Female ( ICAR / NBAIR / P1165 ), INDIA: Assam: Dibrugarh, Krishi Vigyana Kendra , 27.79111°N 94.9119°E, 109 m, YPT, 07.XI.2014, ARK . Paratype: 1 female, ( ICAR / NBAIR / P1176 ), Andaman and Nicobar islands: Great Nicobar, Campbell Bay , 7.0077°N, 93.9147°E, 13 m, YPT, 22 .III .2016, KV.

Etymology

This species is named ‘ nigricephalus ’ referring to its black head. The name is treated as an adjective.

Diagnosis

Cremastobaeus nigricephalus is closer to C. cornutus but differs from it in the following character states. In C. nigricephalus the anterior margin of T1 is not visible when viewed dorsally, metascutellum coriaceous reticulate in anterior half and predominantly smooth in posterior half with four vertical striae and pleuron without distinct foveae; whereas in C. cornutus the anterior margin of T1 is visible when viewed dorsally, metascutellum with median furrow and two large smooth cells on either side and pleuron with distinct foveae.

Figures

Figure 16. Bright field images of Cremastobaeus nigricephalus sp. nov. (female) (a) Habitus (dorsal view); (b) frons; (c) head, mesosoma and horn on T1; (d) meso- and metascutellum; (e) pleuron and horn on T1; (f) antenna; (g) metasoma; (h) wings.