Sunday, May 21, 2023

[Entomology • 2023] Rediscovering A Species not seen for a Hundred Years, Stathmopoda tacita (Meyrick, 1913) (Lepidoptera: Stathmopodidae), with its unusual Fern-spore-feeding Life History

Stathmopoda tacita (Meyrick, 1913)

in Shen et Hsu, 2023. 

Despite being the second largest group of vascular plants, ferns are scarcely reported being fed by insects when compared to angiosperms. Within these fern-feeding insects, lepidopterans are poorly represented and are restricted only to specific groups in this speciose order. The consumers specialising on fern spores are even scarcer in the order, with the majority being consumers of vegetative structures. Amongst the fern-spore-feeding Lepidoptera, Stathmopodidae is the family with the highest species diversity, even with a subfamily, Cyprininae Sinev, 2015, specialising on fern spores. However, fern-spore-feeding habit is not restricted to this subfamily. To understand the evolution of fern-spore-feeding within this family and to increase our knowledge of insect-fern evolution, detailed studies on fern-spore feeding stathmopodids are essential.

New information: 
The present study rediscovered a rare, fern-spore-feeding, stathmopodid micro-moth, Stathmopoda tacita (Meyrick, 1913), which has not been formally recorded or identified for more than 100 years. We documented the life history of this species and identified several species of Pyrrosia (Polypodiaceae, Platycerioideae) as host for the moth’s larvae. A re-description of the fern-feeding moth is also provided as the original description is obscure in terms of character diagnosis.

Keywords: Pyrossia, Stathmopodinae, microlepidoptera, larval stage, fern-feeding

Life history of Stathmopoda tacita (Meyrick, 1913).
 A The larval shelter (white arrow) on Pyrrosia sheareri. B The larva of S. tacita. C The pupa of S. tacita. D The female adult of S. tacita.

Habitus and genitalia of Stathmopoda tacita (Meyrick, 1913).
A, B Male specimen (NMNS). C, D Female specimen (NMNS).
E, F Male genitalia (Gen. Prep. ZYS-0003, NTNU). G Female genitalia (Gen. Prep. ZYS-0144, NTNU).

Stathmopoda tacita (Meyrick, 1913)

Stathmopoda tacita is similar to S. masinissa Meyrick, 1906 and S. maritimicola Terada & Sakamaki, 2011 (see Terada et al. (2011)), but can be distinguished from these two species by the colour and shape of fascia near apex of forewing. The fascia is oval, ochrous in colour in female and vestigial in male in S. tacita, whereas the fascia is creamy-white in colour and triangular in both sexes of S. masinissa. For S. maritimicola, the fascia is triangular, yellow in colour in both sexes and sometimes vestigial in male.

In genitalia, these species can be distinguished by the presence of cervix bursae. Cervix bursae are absent in S. tacita, but well-developed in the other two species.

 Zong-Yu Shen and Yu-Feng Hsu. 2023. Rediscovering A Species not seen for a Hundred Years, Stathmopoda tacita (Meyrick, 1913) (Lepidoptera, Stathmopodidae), with its unusual Fern-spore-feeding Life History.  Biodiversity Data Journal. 11: e101468. DOI: 10.3897/BDJ.11.e101468