Caccothryptus tardarsauceae

Caccothryptus tardarsauceae is a species of minute marsh-loving beetle in the subfamily Limnichinae. The species was described alongside five other Caccothryptus species by Natural History Museum entomologist Keita Matsumoto in 2021, using a male specimen gathered in 1953 by Harry George Champion in Haldwani, India. One of Champion's specimens was distinguished from its initial classification of C. ripicola due to distinct genital structures. The species was named for Tardar Sauce, also known as Grumpy Cat, a pet cat which had become an internet celebrity prior to her death in 2019.

Taxonomy
The Limnichidae (minute marsh-loving beetle) genus Caccothryptus was first described by David Sharp in 1902. In 2014, the genus was divided into five species groups by Carles Hernando and Ignacio Ribera.

A group of Caccothryptus specimens were collected in 1953 by forester Harry George Champion in the Haldwani division of the Kumaon Himalayas, India. These were labeled as C. ripicola and C. testudo, which Champion had previously described in 1923. These were stored at the British Natural History Museum. In 2021, Natural History Museum entomologist Keita Matsumoto identified a number of distinct species from these specimens. A single male specimen was identified as the holotype for Caccothryptus tardarsauceae. C. tardarsauceae was placed in the species group C. testudo and named for Tardar Sauce (also known as Grumpy Cat), a cat popular in internet memes who had died in 2019, two years prior to the species' formal description.

Description
The Caccothryptus tardarsauceae specimen identified has an elytral length of 3.64 mm, and elytral widths of 2.50 mm. Their prothorax is 0.87 mm in length and 2.11 mm in width. C. tardarsauceae has an elongated oval body, brown in colour except for reddish tibia and long, white setae, which are distributed across both the upper and lower sides of the beetle. Its tarsi are divided into five segments, of increasing length, with the fifth segment as long as the others combined. It has long, narrow, light brown tarsal claws. The beetle's head, smooth and punctured, is slightly retracted into its pronotum, and features eleven-segment antennae.

The beetle's genitals display a number of differences from the original classification of C. ripicola, which enabled its classification as a separate species. C. tardarsauceae 's parameres sinuate along their upper side, forming two concave curves. Its median lobe is narrow and slightly pointed along its side. The depression between the apical notches on C. tardarsauceae 's parameres has a gently pointed end, while the notches themselves are v-shaped from the side.