Tetragnatha lactescens ( Mello-Leitão, 1947 )

Castanheira, Pedro De Souza & Baptista, Renner Luiz Cerqueira, 2020, Notes on slender species of the long-jawed spider genus Tetragnatha (Araneae Tetragnathidae) with description of three new species, Zootaxa 4768 (1), pp. 43-75 : 72-73

Tetragnatha lactescens ( Mello-Leitão, 1947) nomen dubium

( Figs 16E, F )

Agriognatha lactescens Mello-Leitão, 1947: 11 , fig. 25 (Holotype female immature from Carmo do Rio Claro, Minas Gerais state, Brazil, J. C. M. Carvalho coll., poorly preserved, abdomen loose, examined).

Tetragnatha lactescens Dimitrov & Hormiga, 2009: 98 , fig. 64A–D (transfer to Cyrtognatha = lapsus).

Notes. This species was described by Mello-Leitão (1947) as an adult female in the genus Agriognatha O. Pickard-Cambridge, 1896 , later considered a junior-synonym of Cyrtognatha by Dimitrov & Hormiga (2009). Those authors also transferred the species to Tetragnatha , due to its similar morphology, and illustrated the internal genitalia, affirming it had a “bizarre morphology” ( Dimitrov & Hormiga 2009 fig. 64A, C, D). We believe the rather damaged holotype is an immature female, due to its small body and its short and undeveloped chelicerae ( Fig. 16E, F ). We also consider the “bizarreness” of the internal genitalia (unfortunately lost) as a sign that it is underdeveloped, thus showing a pattern not found in any genitalia of fully-grown females we examined. Therefore, we consider this species as a nomen dubium.

Acknowledgments

We would like to thank all curators for the loan of specimens, for depositing type-material in their collections, or for kindly receiving the first author in their institutions. Also, we are thankful to Dr. Feng Zhang and Dr. Akio Tanikawa for sending many photos of one of the new species and for properly depositing its type-material, and Julia Stigenberg and Gunvi Lindberg for the photos of T. chauliodus ’ syntypes (© 2020 Naturhistoriska Riksmuseet) – Made available by the Swedish Museum of Natural History under Creative Commons Attribution 4.0 International Public License, CC-BY 4.0 [https://creativecommons.org/licenses/by/4.0/legalcode]. We are in debt to Dr. José Ricardo M. Mermudes for the use of the automontage microscope at Laboratório de Entomologia/UFRJ and to Marcelo Henrique de Oliveira for all the assistance on taking SEM photos at Laboratório de Imagem/UFRJ. Finally, we thank the editor Dr. Gustavo Hormiga and three anonymous reviewers for the welcome suggestions that enriched our manuscript, completely re-shaping it. This study was only possible due to a Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) scholarship (88882.183274/2018-01) and a Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) travel grant to the first author.

Figures

FIGURE 16. Nomina dubia: A, T. exilima female holotype, habitus lateral view (detail, left chelicera inner view). B, T. exilima holotype label. C, T. filigastra male holotype, carapace lateral view. D, T. filigastra holotype label. E, T. lactescens holotype female, habitus lateral view. F, T. lactescens holotype label.