Topic
Gaster
About: Gaster is a research topic. Over the lifetime, 30 publications have been published within this topic receiving 83 citations.
Papers
TL;DR: Gaster length proved to be a good character for separating the two groups, showed the lowest measurement error, and its percentage coefficient of variation was not greater than for other characters, indicating that gaster length should not be discarded out‐of‐hand as a morphometric character in Pteromalidae.
Abstract: We demonstrate by multivariate ratio analysis (MRA) the validity of two female colour morphs as separate species in what was previously regarded as a single species, Trigonoderus cyanescens (Forster, 1841) (Hymenoptera: Pteromalidae). As a result, T. pedicellaris Thomson, 1878 stat.r., is resurrected from synonymy under T. cyanescens and T. filatus binubilatus Erdős, 1960 syn.n. is synonymized with T. cyanescens. More than 20 characters were measured as part of two MRA dataset analyses. The first analysis excluded all measurements related to the gaster, whereas the second included gaster length, gaster breadth and seventh gaster tergite breadth. The first analysis revealed that the best separating morphometric ratios for the two species are head breadth:metatibia length and OOL:parastigma length, whereas the second analysis revealed OOL:gaster length as the second best separating ratio. The measurement error of all characters was below the admissible level of 30%. Gaster length proved to be a good character for separating the two groups, showed the lowest measurement error, and its percentage coefficient of variation was not greater than for other characters. This indicates that gaster length should not be discarded out-of-hand as a morphometric character in Pteromalidae. The variables that gave the best separating ratios included different body parts; therefore we suggest that the body of a specimen should be taken as a whole for use in MRA analyses, where each distance measurement can interact freely with any other. A key, figures and re-descriptions of T. cyanescens and T. pedicellaris are provided.
28 citations
14 citations
Journal Article•
8 citations
2 Apr 2009
7 citations
TL;DR: Article 29.3.1 of the International Code of Zoological Nomenclature dictates that family group names are formed by deleting the case ending from the genitive singular, when the genus ends in a Latin or classical Greek word.
Abstract: Article 29.3.1 of the International Code of Zoological Nomenclature dictates that family group names are formed by deleting the case ending from the genitive singular, when the genus ends in a Latin or classical Greek word (ICZN 1999). This process determines the genitive stem of the word. Formation of a family group name based on an incorrect genitive stem is considered an incorrect original spelling, and the Code requires that it be be automatically changed to the correct stem if described before 1999 in cases where this does not create a junior homonym (Article 35.4.1). Implicit in the wording of these articles is the assumption that there is only one correct genitive stem for each classical word. This assumption is not challenged in most situations, and typically an incorrectly formed family name will be changed to the correct form without discussion. This can be called an assumption of objectivity in choice of genitive stems, meaning that there is assumed to always be one correct form. Correcting spelling of the stem when forming family-group names is not considered to be a nomenclatural act, and is done automatically by authors who find this error. The correctly formed name is given the same authorship and publication date as the incorrectly formed name. Unfortunately, a few words have had multiple genitive stems in classical literature, and this has led to some confusion.
5 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 2 |
| 2019 | 1 |
| 2016 | 2 |
| 2014 | 1 |
| 2013 | 3 |
| 2012 | 1 |