Bioacoustics of Epiophlebia laidlawi

Differential diagnosis of adults Adult E. l. daliensis is similar to E. l. laidlawi in body proportions and size ( Fig. 3e ), with a very long and slender abdomen, but the body coloration and structures of caudal appendages and secondary genitalia differ clearly. Epiophlebia l. daliensis also shares some characters in E. superstes , but E. superstes is much smaller with a relatively shorter abdomen ( Fig. 3a, 3b ). Based on the comparison of body coloration, head, male caudal appendages and secondary genitalia and female ovipositor, we rank E. l. daliensis as a subspecies of E. laidlawi . These differences are discussed below. The body coloration is fundamentally blackish with yellow stripes in E. l. daliensis. and E. superstes but more brownish with fewer yellow stripes in E. l. laidlawi , yellow stripes most developed in E. superstes ( Fig. 3a, 3b ), less in E. l. daliensis ( Fig. 3c, 3d ) and reduced in E. l. laidlawi ( Fig. 3e ). Three pairs of yellow stripes present on synthorax in E. superstes ( Fig. 3a, 3b ) and E. l. daliensis ( Fig. 3c, 3d ) but only two pairs in E. l. laidlawi ( Fig. 3e ), and yellow markings largely developed in E. superstes , the thorax of E. superstes shows additional ventrolateral markings and yellow spots on the coxae and the prothorax. The coloration of the abdomen is brownish with a dorsoventral color gradient to nearly black towards the tip of the tergites in E. l. daliensis ( Fig. 3c, 3d ) and E. l. laidlawi ( Fig. 3e ), whereas the color of E. superstes is black all over ( Fig. 3a, 3b ). S2–7 with white narrow stripes along the ventral margin in E. l. daliensis but less developed in E. l. laidlawi and E. superstes . Epiophlebia superstes is covered with black and yellow hairs, whereas E. l. daliensis and E. l. laidlawi displays less hair, which is brown. Legs are largely black in E. superstes ( Fig. 3a, 3b ), almost black except the coxa, trochanter and base of femur tinted with reddish brown in E. l. daliensis ( Fig. 3c, 3d ), but femur with extensive reddish brown in E. l. laidlawi ( Fig. 3e ). The head of E. l. daliensis and E. l. laidlawi is colored in different shades of brown up to black without any yellow markings, opposed to the black colored head with yellow mouthparts, antefrons and vertex of E. superstes , the mouthparts, antefrons and vertex of E. l. daliensis and E. l. laidlawi are lighter brown or reddish brown. Büsse (2016) found the vertex is V-shaped in E. superstes and U-shaped in E. l. laidlawi , which is not clearly separated in specimens studied here, they are all U-shaped form but in E. l. daliensis and E. superstes the vertex is more raised from frontal view than in E. l. laidlawi which is shorter. The caudal appendages of all three taxa are rounded and simple and have a uniform shape ( Fig. 4 ). Although in E. superstes , additional ventral branches are developed ( Fig. 4a ). The shape of inferior appendage is very similar in E. l. daliensis and E. l. laidlawi but differs in some aspects. From lateral view it is slightly longer than the superiors in E. l. daliensis ( Fig. 4d ) thus from dorsal view it could be seen ( Fig. 4e ), but shorter or equal length with superiors in E. l. laidlawi ( Fig. 4g ) thus hard to see it from dorsal view ( Fig. 4h ). From ventral view the inferior appendage is clearly wider than the superiors in E. l. daliensis ( Fig. 4f ) but it is entirely hidden beneath the superiors in E. l. laidlawi ( Fig. 4i ). The valves of the genital valvule on the 9 th sternum also of different shape in three species: the valves curved and forming a round cavity in E. l. daliensis ( Fig. 4f ) but they are straight and forming a triangular cavity in E. superstes ( Fig. 4c ) and E. l. laidlawi ( Fig. 4i ). The male hamulus posterior is anchor-like in E. l. daliensis and E. l. laidlawi with the distal lobe strongly curved ( Fig. 5c, 5e ), but looks like a scorpion’s stinger in E. superstes with the distal lobe almost straight ( Fig. 5a ). The hamuli anterior are long and hook-like in E. l. daliensis and E. superstes in contrast to the shorter and blunt development in E. l. laidlawi , the distal hook is very long and black in ventral view in E. l. daliensis ( Fig. 5c ) and E. superstes ( Fig. 5a ), but short and brown in E. l. laidlawi ( Fig. 5e ). The elevation in the center of the lamina anterior is more protruding and like a pointed ridge in E. l. daliensis ( Fig. 5d ), by contrast, in E. superstes ( Fig. 5b ) and E. l. laidlawi ( Fig. 5f ), it is a flattened convexity. The abdominal process on sternite 8 in female is most developed and sting-like in E. l. daliensis ( Fig. 6b ) than in E. superstes ( Fig. 6a ), it is weakly developed in E. l. laidlawi , resembles a blunt hook by Büsse (2016) . Important morphological differences for discrimination are summarized in Table 3 . These characters are: stable coloration pattern including body ground color, coloration of face, yellow stripes of synthorax; males can be well separated by the structure of shape of caudal appendages and accessory genitalia, females by the shape of process on sternite 8. The limitation is the number of available specimens of both subspecies. The only male specimen of E. l. laidlawi for this study was collected over 30 years ago, the variation is not able to be discussed here. The male drawing of E. l. laidlawi by Gyeltshen et al. (2017) also possesses less yellow markings on abdomen and the ground body color is paler than the new subspecies, identical to our studied male. So, the diagnosis discussed above should be noticed and improved by the increasing of specimens available. Differential diagnosis on larvae The larva of E. l. laidlawi was described by Tillyard (1921) and Asahina (1954) provided a detailed description of E. superstes . The larva of E. l. daliensis differs from the other two by the first flagellar segment of antennal long, and the medial cleft no deep (the first flagellar segment is less than 1/3 of second segment, and medial cleft more than one tenth of the length of prementum in the other three species) ( Fig. 9 ). In addition, the larva of E. l. daliensis can also be separated from that of E. superstes by femora flattened and abdominal stridulatory file of S3 vestigial (femora not strongly flattened, fore femur longer 3.4 times as long as its widest, and abdominal stridula tory file of S3 well developed in E. superstes ( Fig. 10b, 10e ); and from that of E. l. laidlawi by premental cleft short and abdominal stridulatory file of S6 well developed (premental cleft as long as ventral width of palp at midlength and abdominal stridulatory file of S6 less than length of S 6 in E. l. laidlawi ( Fig. 11c, 11e ).

Head . Wider than long, wider than prothorax and slightly narrower than synthorax. Labrum dark brown, wider than frons without marking, slightly scooplike with shallow median indentation. Genae produced forward well beyond the anterior margin of compound eyes and ventrally formed into granule-lined ridge along prementum. Frontoclypeal region with low transverse ridge ( Fig. 8 , 9d ). Occiput rounded on side, but concave at middle. Compound eyes not large. Antennae filiform, 5–segmented, and tightly appressed to face, antennal pedicel 2 times as long as its widest part, shorter than first flagellar segment; first flagellar segment long, about 0.54 times as much as second segment, length of each antennal segment (mm): 0.28, 0.52, 0.6, 0.21, 0.14 ( Fig. 9a, 9d ). Prementum longer and wide, about 1.4 times as long as its widest part, and 2.4 times its width at base, with small marginal setae; medial cleft not deep, less than one-tenth length of prementum, tightly appressed cleft, lateral margins strongly sinuate with dorsally directed flange in basal half ( Fig. 8b–d ). Apical lobe of palp long leaf-like, rounded-truncate at external angle, with a row of irregular protrusions on inner margin; movable hook slightly shorter than distance from base of movable hook to base of palp, surface lustrous; sharply-pointed apex slender ( Fig. 9e ). Mandibles dark brown to black, formula: L 12340 a (m 1, 2, 3, 4 ) / R 1234 y a(m 1, 2, 3, 4 ), incisor teeth rounded, 3> 4> 2> 1, 4 of both molar crest ( Fig. 9f–i ). Maxillae with five long, robust, incurved hooks, and row of long, stiff setae; maxillary palp curved and tapered to blunt point, bearing dense setae ( Fig. 9j–k ). Thorax . Prothorax dark brown to black, trapezoid, circular on lateral margin. Proepisterna and proepimera projected laterally forming V-shaped, bluntly tipped apophyses, or “prothoracic apophyses” ( Fig. 9l ). Synthorax dark brown to black, smooth, hairless and with light brown markings on dorsum. Legs dark brown, not smooth, femora flattened, fore femur longer 2.9 times as long as its widest part ( Fig. 9m ), foretibia with an inner apical brush of palpiform setae; Wing cases parallel, forewing cases reach hind margin of S3, hindwing cases reach to middle of S4 ( Fig. 8 , 9n ). Abdomen . Spindle-shaped and dark brown. Dorsal hooks absent, lateral spines on S7–9 ( Fig. 8 , 9p, 9n ). Widest on segment 7, S 3 to 10 with low medial ridge; abdominal stridulatory file 3 to 7, but vestigial on the S3 and S7, about 1/4 length of S3 and 1/2 length of S7, moderately developed on 4, well developed on S5 and S6 ( Fig. 9n ). Paraproct broad leaf-like, about 1.2mm long with hair-lined inner surface; length of epiproct 0.8mm , male basal lamina with blunt tip, as long as 1/2 of epiproct. Cerci short, 0.43 mm long, shorter than epiproct ( Fig. 9o ). Female gonapophyses well developed, long, near reaching to the end of S9 ( Fig. 9q ).