Expanded generic diagnoses of all life stages of Yaeprimus Sasa et Suzuki, 2000 (Lunditendipes Harrison, 2000, syn. n.) are given. Yaeprimus tropicus comb. n. is redescribed as an adult based on type material. Additionally, a new species Y. balteatus sp. n. from Oriental China is described based on the adult male and pupa. The phylogenetic position of Yaeprimus within Chironomini and the validity of the new species are explored based on concatenated five genetic markers (18S, 28S, CAD1, CAD4, and COI-3P) through both mixed–model Bayesian inference and maximum likelihood methods. The results strongly support Yaeprimus as sister to Imparipecten Freeman, 1961, which counters a previously proposed systematical position based solely on morphology.

Species of Kaloplocamus Bergh, 1880 are enigmatic Nudibranchia sea slugs, and only two valid species are reported in the northwestern Pacific. Kaloplocamus japonicus (Bergh, 1880) was initially described based on alcohol-fixed specimens. In the latest revision of Kaloplocamus, it was synonymized with Kaloplocamus ramosus (Cantraine, 1835). Recently, several nudibranchs were collected from Tianheng, Shandong Province, China, and one of them is identified as an undescribed species described here as Kaloplocamus albopunctatussp. nov. based on integrated approaches incorporating morphological observations, internal anatomy, and phylogenetic analyses of two mitochondrial (COI, 16S rRNA) genes. The other species is identified as K. japonicus Bergh, 1880 based on the anatomy of the reproductive system. The new species K. albopunctatussp. nov. is similar to K. ramosus in having a bright orange-red color pattern but differs significantly in the structure of appendages and reproductive system. Kaloplocamus japonicus can be easily distinguished from other Kaloplocamus species by its translucent, white-pink coloration and unique features of the female reproductive organ. Both species are supported as distinct species in all molecular analyses. The phylogenetic analyses propose a new estimate of the relationship between Kaloplocamus and Plocamopherus, and the evolution of bioluminescence within Triophinae is discussed. Our results also suggest cryptic biodiversity within the K. ramosus species complex.

Descriptions of two Chironomini pupal types collected in Yunnan Province are given. Among known genera, both types closely resemble that of the North American Hyporhygma Reiss, 1982, but the spine and spinule pattern of the dorsal abdomen does not fit within the current taxonomic boundaries, and represent an endemic component in the Oriental region. A new genus description is expected when associated adults are available.