Abstract
The reduction of fore-wing venation by Mesozoic Trichoptera presumably occurred in two directions. The first, traditional direction was related to the decrease in size of their bodies, and it has been recorded for Trichoptera found in Cretaceous fossil resins. These insects are very small, they have a strongly reduced venation, which is more typical for Cenozoic or recent caddisflies than for the Cretaceous ones. Botosaneanu & Wichard (1983) described the family Taymyrelectronidae from Cretaceous resins from the Taymyr Peninsula, whose representatives had a common area free of any veins in their forewings other than DC, MC, and TC cells. The second direction is typical for primitive Trichoptera and does not concern the size of their bodies. Starting with the beginning of the Mesozoic, the Triassic and the Lower Jurassic, certain changes in the caddisflies’ morphology were noted. Thus, the reduction of veins occurred by their merging, desclerotization, disappearance, and formation of strange large bullas on R. The reduction occurred by the merging of veins, or their desclerotization or disappearance (e.g., loss of forks F1 and F4 in Dysoneuridae Sukatsheva 1968 and Baissoferidae Sukatsheva 1968). Among recent caddisflies, the Kokiriidae McFarlane 1964 are close to the Mesozoic ones because they do not have forks F1 and F4 in their forewings.
References
Botosaneanu, L., Jahnson, R.O. & Dillon, P.R. (1998) New caddisflies (Insecta: Trichoptera) from Upper Cretaceous amber of New Jersey, USA. Polskie Pismo Entomologiczne, 67 (3−4), 219−231.
Botosaneanu, L. & Wichard, W. (1983) Upper Cretaceous Siberian and Canadian amber caddisflies (Insecta: Trichoptera). Bijdragen tot de Dierkunde, 53, 187−217.
Handlirsch, A. (1939) Neue Untersuchungen über die fossilen Insekten mit Ergänzungen und Nachträgen sowie Ausblicken auf phylogenetische, palaeogeographische und allgemein biologische Probleme. II. Theil. Annalen des Naturhistorischen Museums in Wien, 48, 1–240.
McFarlane, R. (1964) A new endemic subfamily and other additions and emendations to the Trichoptera of New Zealand (part 5). Records of the Canterbury Museum, 8, 55−79.
Ponomarenko, A.G., Aristov, D.S., Bashkuev, A.S., Gubin, Yu.M., Khramov, A.V., Lukashevich, E.D., Popov, Yu.A., Pritykina, L.N., Sinitsa, S.M., Sinitshenkova, N.D., Sukatsheva, I.D., Vassilenko, D.V. & Yan, E.V. (2014) Upper Jurassic Lagerstatte Shar Teg, southwestern Mongolia. Paleontological Journal, 48 (14), 1573–1682.
http://dx.doi.org/10.1134/S0031030114140160Rohdendorf, B.B. (1946) Evolyutsiya kryla i filogenez dlinnousykh dvukrylykh Oligoneura (Diptera, Nematocera) [The evolution of the Wing and the Phylogeny of Oligoneura (Diptera, Nematocera)]. Trudy Paleontologicheskogo Instituta Akademii Nauk SSSR 13(2). Akademia Nauk SSSR, Moscow-Leningrad, 108 pp. [in Russian, with English summary]
Rohdendorf, B.B. (1949) Evolyutsiya i klassifikacia letatelnogo apparata [Evolution and classification of flying apparatus]. Trudy Paleontologicheskogo Instituta Akademii Nauk SSSR XVI. Nauka, Moscow, 108 pp. [in Russian]
Sukatsheva, I.D. (1968a) New Jurassic Trichoptera from Karatau. In: Rohdendorf, B.B. (Ed.), Yurskie nasekomye Karatau [Jurassic insects of Karatau]. Nauka, Moscow, 175−180. [in Russian]
Sukatsheva, I.D. (1968b) Mesozoic caddisflies of Transbaikalia. Paleontological Journal, 2, 175−180. [in Russian]
Sukacheva, I.D. (2000) New fossil Caddis Flies (Trichoptera) from Shar-Teg locality in Mongolia. Paleontological Journal, 34 (3), S347–S351.
Sukatsheva, I.D. & Vassilenko, D.V. (2011) Caddisflies from Chernovskie Kopi locality (Jurassic/Cretaceous Transbaikalia). Zoosymposia, 5, 434–438.
Sukatsheva, I.D. & Vassilenko, D.V. (2013) New taxa of caddisflies (Insecta, Trichoptera) with reduced forewing venation from the Mesozoic of Asia. Paleontological Journal, 47 (1), 77–83.
http://dx.doi.org/10.1134/S0031030113010139