Discovery of the male of Loxaulus hyalinus, and implications for the sympatric species Loxaulus laeta (Hymenoptera: Cynipidae: Cynipini): an integrative taxonomical case of species delimitation

ABSTRACT

Loxaulus hyalinus Pujade-Villar & Melika, 2014 was originally described as an asexual form but the recent collection of male samples confirms that it is, actually, a sexual form. The male of L. hyalinus is here morphologically described. With L. hyalinus being a sexual form, the reasonable question arises whether it may be the alternate generation of the only other Loxaulus species currently known from Mexico, L. laeta Pujade-Villar, 2014 (asex). An analysis of the phylogenetic relationships between L. hyalinus (sex) and L. laeta (asex) shows an uncorrected genetic distance variation between sympatric and allopatric individuals averaging 6.4% (range 5.9–6.9%) between the two species independently of the sampled locality. Four different species delimitation models – Automatic Barcode Gap Discovery (ABGD), Bayesian implementation of the Poisson tree processes (bPTP), Bayesian Phylogenetics and Phylogeography (BPP), and Bayesian Factor Delimitation (BFD) – support the distinctiveness of the two Loxaulus species.

KEYWORDS:

• species delimitation
• alternating generations
• COI
• cytb
• 28S
• Mexico

Acknowledgments

We sincerely thank Dr Enrique Guízar Nolazco (Universidad Autónoma Chapingo) for identifying Q. castanea from L. laeta galls. This study has been carried out thanks to the grant APIF 2019/2020 (Universitat de Barcelona and Banco Santander).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Banco Santander [Beca APIF 2019/2020].