The Waterston’s evaporatorium of Ceraphronidae (Ceraphronoidea, Hymenoptera): A morphological barcode to a cryptic taxon

The Waterston’s evaporatorium (=Waterston’s organ), a cuticular modification surrounding the opening of an exocrine gland located on metasomal tergite 6, is characterized and examined for taxonomic significance within the parasitoid wasp family Ceraphronidae. Modification of the abdominal musculature and the dorsal vessel are also broadly discussed for the superfamily Ceraphronoidea, with a novel abdominal pulsatory organ for Apocrita being discovered and described for the first time. Cuticular modification of T6, due to the presence of the Waterston’s evaporatorium, provides a character complex that allows for genus- and species-level delimitation in Ceraphronidae. The matching of males and females of a species using morphology, a long standing challenge for the group, is also resolved with this new character set. Phylogenetic analysis including 19 Waterston’s evaporatorium related characters provides support for current generic groupings within the Ceraphronidae and elaborates on previously suggested synapomorphies. Potential function of the Waterston’s organ and its effects on the dorsal vessel are discussed.

Description of Hemienchytraeus wuhanensis sp. nov. (Annelida, Clitellata, Enchytraeidae) from central China, with comments on species records of Hemienchytraeus from China

Hemienchytraeus wuhanensissp. nov. is described from hardwood forest soil in Wuhan, China. This moderately sized enchytraeid species of 6–9 mm body length is characterized by: (1) an oesophageal appendage with tertiary branches, (2) three pairs of secondary pharyngeal gland lobes in V, VI, VII, (3) five pairs preclitellar nephridia, from 5/6 to 9/10, (4) dorsal vessel originating in clitellar segments, (5) a girdle-shaped clitellum, (6) a relatively small male reproductive apparatus without seminal vesicle, and (7) spermathecae that extend to VI–VII. DNA barcodes of paratype specimens of the new species are provided. Previous species records of Hemienchytraeus from China are critically discussed.

Decimodrilus, a new enchytraeid genus from Korea (Annelida, Clitellata, Enchytraeidae)

Two new species of the new genus Decimodrilus gen. n. are described in this paper from oak forests of South Korea using a combination of classical morphology and DNA-based molecular taxonomy. A characteristic trait of the new genus is the occurrence of the intestinal diverticula in segments IX–X. The main morphological features of the new genus are: 4–5(6) straight chaetae per bundle, origin of dorsal vessel in clitellar region, anteseptale of nephridia consisting of funnel only, coelomocytes only mucocytes, oesophageal appendages absent, spermathecae united proximally and connected jointly with the oesophagus. Decimodrilus diverticulatus sp. n. has spermathecae with two diverticula-like protrusions and two globular sperm masses. D. globulatus sp. n. has spermathecae with two or three sperm rolls. Molecular taxonomic analysis based on a concatenated phylogenetic tree supports the status of the new genus and that of the two new species.

On the Anatomy and Histology of the New Earthworm (Diplocaedi communis)

Vasa deferentia opening to the exterior behind the clitellus by two apertures on the ventral side of somite 19. Two copulatory fossae extend from the middle of the ventral side of somite 18 to the middle of the ventral side of somite 20, each fossa with a pair of long, curved setee and an outlet of a prostate gland at its extremities. Internal apertures of the vasa deferentia two pairs; one pair in each of the somites 10 and 11. Seminal vesicles in somites 9, 10, and 11. Testes in somite 12. Spermathecae in three pairs, one pair in each of the somites 7, 8, and 9. Ovaries flabelliforra, situated in somite 13. Internal apertures of oviducts in somite 13; external apertures in somite 14. Setae arranged in four double longitudinal series on the ventral side of the body, each somite bearing four pairs. (Esophagus very short, without calciferous glands. A muscular gizzard in somites 6 and 7. Typhlosole a very slight dorsal fold. Dorsal vessel double, consisting of two tubes fused only at the dissepiments. No subneural blood vessel present. Nephridia tubular, with the nephridiopores in line with the dorsal setse of the external pairs; internal aperture in the somite preceding that in which the gland lies. Brain small, transversely elongated, with slight median anterior and posterior excisions. Praestomium not completely dividing the integument of the first somite.

Insect Muscular Tissue-Powered Swimming Robot

Bio-actuators that use insect muscular tissue have attracted attention from researchers worldwide because of their small size, self-motive property, self-repairer ability, robustness, and the need for less environment management than mammalian cells. To demonstrate the potential of insect muscular tissue for use as bio-actuators, three types of these robots, a pillar actuator, a walker, and a twizzer, have been designed and fabricated. However, a model of an insect muscular tissue-powered swimming robot that is able to float and swim in a solution has not yet been reported. Therefore, in this paper, we present a prototype of an insect muscular tissue-powered autonomous micro swimming robot that operates at room temperature and requires no temperature and pH maintenance. To design a practical robot body that is capable of swimming by using the force of the insect dorsal vessel (DV), we first measured the contraction force of the DV. Then, the body of the swimming robot was designed, and the design was confirmed by a simulation that used the condition of measured contraction force. After that, we fabricated the robot body using polydimethylpolysiloxane (PDMS). The PDMS body was obtained from a mold that was fabricated by a stereo lithography method. Finally, we carefully attached the DV to the PDMS body to complete the assembly of the swimming robot. As a result, we confirmed the micro swimming robot swam autonomously at an average velocity of 11.7 μm/s using spontaneous contractions of the complete insect DV tissue. These results demonstrated that the insect DV has potential for use as a bio-actuator for floating and swimming in solution.