Apertoma Sun, Rasnitsyn, Zhuang & Shih 2024, gen. nov.

Apertoma Sun, Rasnitsyn, Zhuang & Shih gen. nov. Xyelotoma Gao * Ren & Shih* 2009; Ann. Entomol. Soc. Am. 102(4)* p. 589* fig. 1 (partim* only for Xyelotoma macroclada Gao * Ren & Shih* 2009). Type species: Apertoma (Xyelotoma) macroclada Gao* Ren & Shih* 2009. Etymology: The generic name is a combination of the Latin ‘Aper-’* meaning discrete* referring to the unique triple-branched Sc in the forewing* and ‘-toma’ from the type genus Undatoma Rasnitsyn * 1977. Gender feminine. Included species: Type species only. Diagnosis: Forewing with pterostigma medium wide* sclerotized. Sc with stalk distant from R* ending at R well before free Sc 1 * the latter forming oblique crossvein. 1-Rs present* short. 1-M much longer than 2-Cu. Cell 1mcu long* with its upper side three times as long as 1m-cu. Remarks: Under the present concept of Blasticotomidae * the type species cannot be included in Xyelotoma and is assigned to Apertoma gen. nov. in the subfamily Undatominae because of 1-Cu bent and cell 1mcu long and widened apically. These characters* together with M+Cu aligned with 1-Cu* are characteristic of Undatominae. Within that subfamily* the new genus is unique in the form of Sc splitting into stalk ending to R* and crossvein-like Sc 1 well distant from the stalk. For additional details* see the key below.