Addendum to the description of Steinernema carpocapsae (Weiser, 1955) Wouts, Mracek, Gerdin & Bedding, 1982

摘要

In the light of current morphological knowledge, the Steinernema carpocapsae morphology is not satisfactorily described, some important characters of this species are missing and no thorough molecular characterisation of this species has been performed. Steinernema carpocapsae represents a type of the 'carpocapsae' group and thus a main objective of this study was to add characters such as, infective juvenile hyaline layer with %H, tail morphometry with ratio c', shape and protuberances on the F1 tail etc., to the general knowledge about this species. We further aimed to sequence ITS region and D2-D3 regions of the ribosomal DNA, and compare them with the sequences for S. carpocapsae available in the GenBank NCBI database. Four S. carpocapsae isolates (strains) were studied (USA - DD136 and All, Russian - Agriotos and Swiss - DOK83). Morphology was identical for all isolates and morphometry close each to other. Infective juveniles possess rather narrow, continuous and hemispherically rounded head, lateral field with six ridges (seven lines) with the less prominent central pair, hyaline layer occupies about 40-44% of the tail length, ratio c' varies from 4.0 (3.8-4.1) to 4.2 (3.9-4.4) and ratio %E from 71 (59-82) to 79 (74-83). First generation females possess a characteristic blunt tail with a terminal, conical sharply ended peg and no other minute protuberances and rounded vulva slightly protruding from the body contour. All male generations possess the only minute mucron and there was little size difference between the first and second (other) generations. Both studied genetic markers effectively characterize S. carpocapsae as a species, showing very low interspecific variation. However, the status of the closely related species S. anatoliense and S. websteri seems to be doubtful.