''Caccothryptus championi'' 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 specimens gathered in 1953 by Harry George Champion in

Haldwani Haldwani (Kumaoni language, Kumaoni: ''Haldvānī'') is the largest city of Kumaon division, Kumaon. It is also the second List of cities in Uttarakhand by population, most populous city in the Indian state of Uttarakhand. Haldwani is said to be ...

, India alongside an earlier 1925 specimen collected nearby. Like the other ''Caccothryptus'' species described by Matsumoto, it was distinguished from its original classification of ''C. ripicola'' due to differences in the shape of its genitalia. Twenty-seven specimens from the British Natural History Museum collection were identified with ''C. championi,'' named after Champion.

Taxonomy

The

Limnichidae Limnichidae, commonly called minute marsh-loving beetles, is a family of beetles belonging to Byrrhoidea. There are at least 30 genera and 350 described species in Limnichidae. They are found worldwide, with the greatest diversity in tropical regi ...

(minute marsh-loving beetle) genus ''

Caccothryptus ''Caccothryptus'' is a genus of Limnichidae, minute marsh-loving beetles in the subfamily Limnichinae. The genus was formally established (Circumscription (taxonomy), circumscribed) by the entomologist David Sharp (entomologist), David Sharp in ...

'' 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

division of the Kumaon Himalayas, India. These were labeled as C. ''ripicola'', 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. One male specimen was labeled as the holotype of ''Caccothryptus championi.'' Twenty-six other specimens, including an earlier individual collected in 1925, were labeled as paratypes. ''C. championi'' was placed in the species group ''C. testudo'' and named for Champion.

Description

The ''Caccothryptus championi'' specimens identified have an elytral length of 2.35–2.74mm, and elytral widths of 0.87–1.04 mm. Their prothoraces measured 1.97–2.16 mm in length and 3.01–3.33 mm in width. ''C. championi'''s body is dark brown spare for reddish-brown

tibia The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...

and patches of long

seta In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae, ...

e, yellow along the underside and white on the dorsum. 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 This glossary describes the terms used in formal descriptions of spiders; where applicable these terms are used in describing other arachnids. Links within the glossary are shown . Terms A * Abdomen or opisthosoma: One of the two main body par ...

. The beetle's head, smooth and punctured, is slightly retracted into its

pronotum The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on e ...

, and features eleven-segment antennae. Little sexual dimorphism exists between the male and female specimens, beyond a longer fifth abdominal

ventrite The sternum (: sterna) is the ventral portion of a segment of an arthropod thorax or abdomen. In insects, the sterna are usually single, large sclerites, and external. However, they can sometimes be divided in two or more, in which case the sub ...

on the female. 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. championi'''s has ovoid apexs on its

median lobe The median of a set of numbers is the value separating the higher half from the lower half of a data sample, a population, or a probability distribution. For a data set, it may be thought of as the “middle" value. The basic feature of the medi ...

. Their

paramere Parameres ('side parts') are part of the external reproductive organs of male insects and the term was first used by Karl Wilhelm Verhoeff, Verhoeff in 1893 for the lateral genital lobes in Coleoptera. The primary phallic lobes which appear in th ...

s narrow from a top-down view, with v-shaped notches along their bottom and a slight bump on their side near the apex. Between the parameres is a deep, narrow depression forming a pointed V-shape. Females have long

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typica ...

References

Bibliography

* {{Taxonbar, from=Q127206101 Limnichidae Beetles described in 2021 Beetles of Asia