Kazakhstan is the 9^th largest country in the world. The territory of Kazakhstan features mountains, steppes, forests, and deserts; the most widespread landscapes are deserts and steppes. Water covers only 1.5% of the area. Nevertheless, Kazakhstan’s territory counts over 8.5 thousand small and large rivers, and 48 thousand large and small lakes.

The unique geographical position of Kazakhstan in the center of the Eurasian continent, and the wide variety of landscapes and water bodies provide conditions for the formation of a diverse fauna of caddisflies. At the same time, the history of this region with periods of glaciation and desiccation affected the formation of the caddis fauna. The Kazakhstan territory borders three zoogeographic provinces according to division by de Moor and Ivanov (2008).

The history of the study of caddisflies in Kazakhstan began with the works of A.V. Martynov (1910, 1914, 1927a, 1927b) at the beginning of the 20^th century. In 2016, a summary of the Kazakhstan fauna of caddisflies was made according to the literature data (Smirnova et al. 2016). The project “Assessment of the biodiversity of caddisflies (Trichoptera) in water bodies of Kazakhstan” was implemented in 2015–2017 to obtain missing information about the fauna, the distribution and occurrence of caddisflies, and to preserve their diversity. During this project, a Kazakh-Russian expedition to the north-east of the country took place. As a result, the list of caddis fauna of Kazakhstan was replenished with 13 species (Smirnova et al. 2016, 2020; Sklyarova et al. 2018; Sklyarova et al. 2019). More samples consistently add new species to the fauna of Kazakhstan; for example, out of four species collected in western Kazakhstan in spring, two species were new records (Melnitsky et al. 2018).

Some earlier records of caddisfly species are considered doubtful due to their distribution and ecology. For example, in Oláh (2010), the species Goera japonica Banks, 1906, Lepidostoma itoae (Kumanski & Weaver, 1992), Plectrocnemia wui (Ulmer, 1932), Tinodes furcatus Li & Morse, 1997, Molanna moesta Banks, 1906, and Wormaldia niiensis Kobayashi, 1985 were recorded for the middle reaches of the Ile River. These species are distributed in southern China, Korea, Japan, and Far East of Russia in wet forests. We repeatedly collected caddisflies in the middle reaches of the Ile River from 2015 to 2020 from June to September right in the times and places indicated for these species and failed to collect them. Subsequently they were excluded from the list of Kazakhstan caddisflies (Sklyarova et al. 2019). Currently, studies of caddisflies are carried out on a voluntary basis by scientists from various institutions in Kazakhstan, Russia, and Finland.

In this study we present an updated list of new records of caddisflies.

Field collections were accomplished with the well-known methods of light trapping with small water-filled UV pan traps installed close to aquatic habitats, generator-driven multi-lamp tents, net sweeping during the daytime in the riparian vegetation, and hand-picking of insects. All sampled caddisflies are stored in 70% ethanol.

The following 14 species were recorded for the first time in Kazakhstan:

Hydropsychidae

Hydronema persica Martynov, 1914, localities 1, 2, 3, 9.

Hydropsyche carbonaria McLachlan, 1875, localities 1, 4, 5.

Hydropsyche demavenda Malicky, 1977, localities 1, 9.

Hydrobiosidae

Apsilochorema turanicum Martynov, 1934, locality 12.

Hydroptilidae

Hydroptila sp. aff. desertorum Mey, 1993, locality 1.

Hydroptila sanghala Schmid, 1960, locality 2.

Leptoceridae

Setodes sp. aff. punctatus (Fabricius, 1793), locality 6.

Parasetodes respersella (Rambur, 1842), locality 1.

Phryganeidae

Agrypnia varia (Fabricius, 1793), localities 10, 11.

Apataniidae

Apataniana cornuta, ssp. nov., locality 7.

Apataniana sp. nov., locality 8.

Limnephilidae

Limnephilus martynovi Kumanski, 1994, locality 1.

Limnephilus major Martynov, 1909, locality 1.

Philarctus bergrothi McLachlan, 1880, localities 10, 11.

Ongoing studies of caddisflies in Kazakhstan confirmed the lack of knowledge about the species composition and distribution of species across the area. Most of the new findings are species previously found in the surrounding areas.

Such species as Hydronema persica, Hydropsyche carbonaria, and H. demavenda have previously been discovered in nearby Central Asian countries – Uzbekistan, Kyrgyzstan and others (Morse 2024). These species inhabit various mountain streams. The dispersal of these species in the south and southeast of Kazakhstan is also expected. The new findings extend their previously known distribution areas eastwards. We consider here Apsilochorema turanicum Martynov, 1934 as an independent species, not as a subspecies of A. indicum (Ulmer, 1905) because of distinct differences in the male genital structures, especially inferior appendages compatible to the differences of other species in the genus Apsilochorema. A. turanicum was described by A.V. Martynov from the Samarkand area in Uzbekistan (Martynov 1934), some 400 km southwards the Karatau Mountains (Loc. 12).

Hydroptila sanghala and H. desertorum are known in the Xinjiang Uygur Autonomous Region of China, bordering Kazakhstan (Morse 2024). Thus, the finding of H. sanghala in southeastern Kazakhstan was quite expected. The specimens of Hydroptila sp. aff. desertorum may be either a variation of H. desertorum or a species closely related to it.

The species Setodes punctatus and Limnephilus major occur in Europe; they also were found in Siberia, the Far East, and northeast China (Morse 2024). The habitats of these species in Kazakhstan are not so obvious. Parasetodes respersella is a widespread but infrequent species occurring in Southern Europe and in various Asiatic localities (Malicky 2006; Morse 2024).

Both Agrypnia varia and Philarctus bergrothi live in stagnant waters, including brackish ones. A. varia is widespread but local in the western and eastern Palearctic (Morse 2024). Thus, their occurrence in the brackish lakes of northern Kazakhstan was not a surprise. P. bergrothi is a rare species, collected also in the Pamir highlands.

The record of L. martynovi in Temirlik River was unexpected. This species has until now been known only from the type locality in Yakutia.

The species Apataniana cornuta is common in brooks and springs throughout the mountain foothills of the Eastern Kazakhstan from Ile to Irtysh river valleys. Our samples contain a new mountain subspecies with its genitalia as in the original description (Ivanov 1991), but the adults have differences in coloration and ecology.

All these new findings were made in summer; therefore, future records made in previous and new sampling sites in other seasons of the year might bring more species that are new for the Kazakhstan fauna. The current list with addition of new findings counts 169 species in 66 genera of 18 families known from Kazakhstan. Continuing studies are expected to add more entries to this list.