Species Discrimination of Three Odontomachus (Formicidae: Ponerinae) Species in Thailand Using Outline Morphometrics

Abstract

All members of the ant genus Odontomachus Latreille, 1804 are venomous ants. Four species in this genus have been identified from Thailand: Odontomachus latidens Mayr, 1867; O. monticola Emery, 1892; O. rixosus Smith, 1757; and O. simillimus Smith, 1758. The three latter species are available and have been used for an outline morphometric study. They display similar morphology, which makes their distinction very difficult except for highly qualified individuals. A total of 80 worker specimens were studied, exploring the contour shapes of their head and pronotum as possible taxonomic characters. The size of each body part was estimated determining the contour perimeter, the values for which were largely overlapping between O. rixosus and O. simillimus; most O. monticola specimens exhibited a significantly larger size. In contrast to the size, each contour shape of the head or pronotum established O. rixosus as the most distinct species. An exploratory data analysis disclosed the higher taxonomic signal of the head contour relative to the pronotum one. The scores obtained for validated reclassification were much better for the head (99%) than for the pronotum (82%). This study supports outline morphometrics of the head as a promising approach to contribute to the morphological identification of ant species, at least for monomorphic workers.

Wing geometric morphometrics to distinguish and identify Haematobosca flies (Diptera: Muscidae) from Thailand

“…This increased our confidence in their potential application as reference data for further identification of the unknown Haematobosca specimen in our country. The use of GM material as a public reference for species identification has been demonstrated in various insects, such as horse flies ( Changbunjong et al, 2021 ), Stomoxys flies ( Changbunjong et al, 2023 ), and ants ( Samung et al, 2022 ). However, measurement errors are an essential factor that must be considered for its implementation ( Changbunjong et al, 2021 ).…”

Comportamento predatório de operárias de Odontomachus bauri (Hymenoptera: Formicidae) sobre Hermetia illucens (Diptera: Stratiomyidae)

“…Formigas do gênero Odontomachus, assim como outros membros do grupo das Poneromorfas (agrupamento das subfamílias Amblyoponinae, Ectatomminae, Heteroponerinae, Paraponerinae, Ponerinae e Proceratiinae) possuem como característica marcante o fato de serem predominantemente predadoras, contando com espécies tanto generalistas quanto especialistas quanto à alimentação, além de possuírem um ferrão funcional (Brown-Jr, 1976;Bolton, 2003;Samung et al 2022).…”