Arctopsyche McLachlan, 1868

Zhou, Xin, 2009, The larvae of Chinese Hydropsychidae (Insecta: Trichoptera), Part I: Arctopsyche shimianensis, Parapsyche sp. A, and Diplectrona obscura, Zootaxa 2174, pp. 1-17 : 6

Genus Arctopsyche McLachlan, 1868

A total of eight Arctopsyche species were recorded previously from China ( Yang et al. 2005), of which A. shimianensis Gui and Yang, 2000 , A. trispinosa Schmid, 1968 , and two possibly new species, as well as various of larval morphs were collected and sequenced in this study ( Table 1; Fig. 1 ). Lepneva (1964) provided comprehensive larval and pupal descriptions and illustrations for A. palpata Martynov, 1934 , a species with wide distribution including the Russian Far East and the Chinese northeastern provinces and Inner Mongolia. The larval ecology of this species was studied by Kocharina (1997). This is the only Chinese Arctopsyche species whose larvae have been associated.

LARVA — HEAD. Frontoclypeal apotome conspicuously constricted opposite eyes. Genae completely separated by ventral apotome. Ventral apotome narrowed posteriorly [but also tapered in at least one North American Parapsyche species ( Wiggins 1996)]. Submentum trapezoidal, anterior margin not cleft. Stridulating files consisting of series of short, thick bars, very conspicuous. Seta 22 on anterolateral corners of pronotum not conspicuous. Foretrochantin triangular, pointed, not forked. Prosternal plate single-pieced, posterior prosternal sclerites absent. Sagital section of mesonotum more or less triangular. Meso- and metanota bearing transverse ecdysial lines. Abdominal segments covered by regular hair-like setae and elongated club-hairs. Setal areas, Sa 2 and Sa 3 in most abdominal segments each bearing only one single long seta, not cluster of club-hairs. Lateral gills on abdominal pleura similar to ventral gills, with numerous filaments distributed mostly at apex of each stalk. Abdominal segment VII bearing ventral and lateral gills. Ventral plates on abdominal segment IX large.

LARVAL-ADULT ASSOCIATION. For this study 15 individuals of Arctopsyche , representing 6 provisional species (HPGP 1–6, Fig. 1 ), were extracted for DNA amplifications, including two possibly new species (CNCAD_0078 and CNCAD_0191/CNCAD_AT11, Table 1 and Fig. 1 ). Species delimitations are congruent in two genes in 5 of the 6 species. HPGP 4 is split into two subgroups (HPGP 4a and 4b) in the COI tree, with a mean divergence of 8.7% between them, and 0.5% and 0% divergence within HPGP 4a and 4b, respectively. However, members of these two subgroups have essentially identical D2 sequences. Likely, D2 has not evolved as fast as COI gene in this recent speciation. Additional adult materials are needed to clarify the species boundary because HPGP 4b is only represented by larval specimens, which are indistinguishable from that of HPGP 4a. A. shimianensis was associated across both D2 and COI makers. Its larva is described and illustrated.

Figures

FIGURE 1 a – b. Larval-adult association of Chinese Arctopsyche, Parapsyche, and Diplectrona — 1 a. COI neighborjoining phylogram; 1 b. D 2 neighbor-joining phylogram. Specimens are labeled with taxonomy, followed by sample ID (corresponding to Table 1) and province location. Specimens of immature life stage are noted at the end (pp: pharate pupa; lv: larva). COI tree is constructed in the BOLD system using Neighbor-joining and K- 2 - P parameter. D 2 tree is constructed in PAUP * 4.0 b 10 using Neighbor-joining and K- 2 - P parameter. Numbers on the internodes represent the bootstrap values using Neighbor-joining / 1000 replicates. Species boundaries recognized in morphology and two DNA sequences are marked in brackets on the right of each DNA tree and noted as haplogroups (HPGP) 1 - 34 respectively.