First record of Mordellistena multicicatrix Kangas, 1986 (Coleoptera, Mordellidae) in Ukraine: morphological and ecological analysis

Abstract

Mordellistena multicicatrix Kangas, 1986 is recorded for the fauna of Ukraine for the first time. Therefore, currently in Ukraine there are 4 species of tumbling flower beetles from the pentas species group (proposed by K. Ermisch in 1956): M. secreta Horák, 1983, M. pentas Mulsant, 1856, M. dalmatica Ermisch, 1956 and M. multicicatrix. The pupa of M. multicicatrix was found in the pith of the stem of annual fleabane (Erigeron annuus (L.) Desf.) in Chernihiv in 2018. The hatched male was kept in laboratory conditions were it fed on pollen of the common dandelion (Taraxacum officinale F. H. Wigg.). A comprehensive analysis of the obtained data was carried out. The morphological characteristics of M. multicicatrix adults were analyzed and certain ecological characteristics of this species were identified. Until now, the detailed morphology of the M. multicicatrix adult was known only from the species description, which was based on a single male (holotype). Thus, the results of the morphological analysis can be used to take into account the variability of M. multicicatrix when identifying this species of tumbling flower beetles. The article presents the measurement results of the most variable morphological features of M. multicicatrix. Photographs of its habitus and parameres are provided for the first time. It is shown that the ratio of the length of antennomeres 5–10 to their width cannot be used as a feature that would reliably distinguish males of M. multicicatrix from M. secreta. The absence of external signs of suppression of the plant in which the pupa was found can be explained by the fact that during the development of the M. multicicatrix larva, the vascular bundles in the stem remain intact. Based on the analysis of the length of the larval tunnel, which was made by the found specimen when it was at the larval stage, it is shown that M. multicicatrix can lay eggs in the upper third of a stem. The length and diameter of the analyzed larval tunnel indicate the impossibility of the development of two or more M. multicicatrix larvae in one stem. Given the climatic conditions in the Chernihiv region, the find of the M. multicicatrix pupa at the end of April indicates that the development of the larva that preceded it began in June 2017. By the beginning of winter diapause, the larva had reached the last larval instar. Potential threats to M. multicicatrix were identified.