Tribe Myrmeleontini Latreille, 1802

Diagnosis of adult

Forewing vein CuP arising at or very near basal crossvein; forewing vein 2A running close to 1A for short distance, then bending at a sharp angle toward 3A. Hindwing with four or more crossveins at presectoral area. Forewing and hindwing vein RP arising distant from base. Tarsomere 1 of hind leg shorter than tarsomere 5. Male with or without pillula axillaris.

Identification key to the adults of Myrmeleontini species in Taiwan

1. Hindwing longer than or as long as forewing ................................................................................... 2

– Hindwing shorter than forewing ....................................................................................................... 5

2. Wings broad, acute at apex; male mediuncus three-pronged shaped from caudal view (Figs 4C, 7C); female anterior gonapophyses widely separated, long, and shorter than posterior gonapophyses; lateral gonapophyses long (Figs 3A–B, 6A–B) ........................................................3 (genus Baliga)

– Wings variable; male mediuncus not as above; female anterior gonapophyses not widely separated, short, lobed .......................................................................................................4 (genus Myrmeleon)

3. Wings with large, white pterostigma; costal area with interconnected crossveins from apical ⅓ to stigma (Fig. 2C); ventral side of the abdomen whitish-yellow (Fig. 1A) ........................................... ............................................................................................................. B. asakurae (Okamoto, 1910)

– Wings with small pterostigma; costal area with only few interconnected crossveins (Fig. 5C); ventral side of the abdomen dark brown (Fig. 1B) ...................... B. brunneipennis (Esben-Petersen, 1913)

4. Vertex mostly yellow with dark brown spots; pronotum and mesonotum mostly dark brown with whitish-yellow markings (Fig. 11B); ventral side of the abdomen paler than dorsal side (Fig. 1C) .. ..................................................................................................... M. littoralis Miller & Stange, 1999

– Vertex mostly dark brown with a pair of yellow spots; pronotum mostly whitish-yellow with two pairs of dark brown spots on the anterior half and dark brown markings on the posterior half (Fig. 8B) .. ............................................................................................................. M. tenuipennis Rambur, 1842

5. Large sized; pronotum dark brown with a thin yellow line in the middle and a pair of yellow bands on the side of the anterior margin (Fig. 14B) ................................. M. wangi Miller & Stange, 1999

– Small to medium-sized; pronotum not as above ............................................................................... 6

6. Vertex completely dark brown (Figs 20B, 26B) ............................................................................... 7

– Vertex with yellow or brown markings (Figs 17B, 23B) .................................................................. 8

7. Pronotum, mesonotum and metanotum almost fully dark brown (Fig. 26B) ..................................... ................................................................................................ M. taiwanensis Miller & Stange, 1999

– Pronotum dark brown with a yellow medial line, anterior half with yellow spots; mesonotum and metanotum with thin yellow line on the posterior margin (Fig. 20B) ................................................ ................................................................................................... M. persimilis Miller & Stange, 1999

8. Pronotum brown with yellow bands on the side of anterior margin (Fig. 23B) ................................. .............................................................................................................. M. punctinervis Banks, 1937

– Pronotum mostly whitish-yellow with brown markings (Fig. 17B) ................................................... .................................................................................................... M. heppneri Miller & Stange, 1999