Abstract
India harbors unique and largely endemic Blattodea (cockroaches) species richness, with 61% endemism. However, existing research primarily focuses on classical taxonomic methods, resulting in significant gap in context to the systematics and geographic distribution of Indian cockroaches. To address this, comprehensive field sampling was conducted and DNA barcoding was employed as part of Integrative Taxonomic Approach (ITA). From 150 specimens, 50 putative taxa were morphologically identified, and 122 DNA barcodes were generated. Species delimitation analyses revealed the possibilities of 86 to 99 genetic lineages, indicating high morphological cryptic diversity and numerous potential undescribed lineages. From these, 43 lineages could be assigned to known species, while 44 remained unnamed, that may include both already documented and potential new species signifying a complex taxonomy. A preliminary time-calibrated phylogenetic analysis suggests that the diversification of Indian cockroaches began ~162 million years ago, coinciding with the geological separation of the Indo-Madagascar plate with Africa. This study establishes foundational DNA barcode library for Indian cockroaches, enabling multifaceted applications and underscores the need for integrative taxonomy to accelerate documenting of overlooked taxa within cockroaches.
References
- Bouckaert, R., Heled, J., Kühnert, D., Vaughan, T., Wu, C.H., Xie, D., Suchard, M.A., Rambaut, A. & Drummond, A.J. (2014) BEAST 2: a software platform for Bayesian evolutionary analysis. PLoS Computational Biology, 10 (4), e1003537. https://doi.org/10.1371/journal.pcbi.1003537
- Che, Y., Gui, S., Lo, N., Ritchie, A. & Wang, Z. (2017) Species Delimitation and Phylogenetic Relationships in Ectobiid Cockroaches (Dictyoptera, Blattodea) from China. PLoS ONE, 12 (1), e0169006. https://doi.org/10.1371/journal.pone.0169006
- Debnath, R., Rajmohana, K., Sushama, V. & Dinesh, K.P. (2025) DNA metabarcoding of spider egg sacs uncovers novel insights into host–parasitoid complexes and trophic networks. Scientific Reports, 15 (1), 13608. https://doi.org/10.1038/s41598-025-97799-2
- Diniz-Filho, J.A.F., Loyola, R.D., Raia, P., Mooers, A.O. & Bini, L.M. (2013) Darwinian shortfalls in biodiversity conservation. Trends in Ecology & Evolution, 28 (12), 689–695. https://doi.org/10.1016/j.tree.2013.09.003
- Ducasse, J., Ung, V., Lecointre, G. & Miralles, A. (2020) LIMES: a tool for comparing species partition. Bioinformatics, 36, 2282–2283. https://doi.org/10.1093/bioinformatics/btz911
- Evangelista, D.A., Wipfler, B., Béthoux, O., Donath, A., Fujita, M., Kohli, M.K., Legendre, F., Liu, S., Machida, R., Misof, B. & Peters, R.S. (2019) An integrative phylogenomic approach illuminates the evolutionary history of cockroaches and termites (Blattodea). Proceedings of the Royal Society B, 286 (1895), 20182076. https://doi.org/10.1098/rspb.2018.2076
- Fujisawa, T. & Barraclough, T.G. (2013) Delimiting species using single-locus data and the Generalized Mixed Yule Coalescent approach: a revised method and evaluation on simulated data sets. Systematic Biology, 62 (5), 707–724. https://doi.org/10.1093/sysbio/syt033
- Gariepy, T.D., Haye, T. & Zhang, J. (2014) A molecular diagnostic tool for the preliminary assessment of host–parasitoid associations in biological control programmes for a new invasive pest. Molecular Ecology, 23, 3912–3924. https://doi.org/10.1111/mec.12515
- Gupta, S.K. & Chandra, K. (2019) An annotated checklist of cockroaches (Blattodea) from India. Zootaxa, 4614 (3), 461–497. https://doi.org/10.11646/zootaxa.4614.3.3
- Hayashi, Y., Maekawa, K., Nalepa, C.A., Miura, T. & Shigenobu, S. (2017) Transcriptome sequencing and estimation of DNA methylation level in the subsocial wood-feeding cockroach Cryptocercus punctulatus (Blattodea: Cryptocercidae). Applied Entomology and Zoology, 52, 643–651. https://doi.org/10.1007/s13355-017-0519-7
- Hebert, P.D., Cywinska, A., Ball, S.L. & DeWaard, J.R. (2003) Biological identifications through DNA barcodes. Proceedings of the Royal Society of London. Series B: Biological Sciences, 270 (1512), 313–321. https://doi.org/10.1098/rspb.2002.2218
- Joshi, J. & Karanth, K.P. (2011) Cretaceous–Tertiary diversification among selected scolopendrid centipedes of South India. Molecular Phylogenetics and Evolution, 60 (3), 287–294. https://doi.org/10.1016/j.ympev.2011.04.024
- Joshi, J. & Karanth, P. (2013) Did southern Western Ghats of peninsular India serve as refugia for its endemic biota during the Cretaceous volcanism? Ecology and Evolution, 3 (10), 3275–3282. https://doi.org/10.1002/ece3.603
- Kalawate, A.S., Shabnam, A. & Dinesh, K.P. (2022) Additional record of the little known xylophagous endemic wood roach Salganea rehni Roth, 1979 (Blattodea: Blaberidae: Panesthiinae) from the Western Ghats, India with its DNA barcode. Entomon, 47 (4), 443–448. https://doi.org/10.33307/entomon.v47i4.799
- Karanth, P. (2006) Out-of-India Gondwanan origin of some tropical Asian biota. Current Science, 90, 789–792.
- Lanfear, R., Calcott, B., Ho, S.Y.W. & Guindon, S. (2012) PartitionFinder: combined selection of partitioning schemes and substitution models for phylogenetic analyses. Molecular Biology and Evolution, 29 (6), 1695–1701. https://doi.org/10.1093/molbev/mss020
- Legendre, F., Nel, A., Svenson, G.J., Robillard, T., Pellens, R. & Grandcolas, P. (2015) Phylogeny of Dictyoptera: dating the origin of cockroaches, praying mantises and termites with molecular data and controlled fossil evidence. PLoS ONE, 10 (7), e0130127. https://doi.org/10.1371/journal.pone.0130127
- Luo, X., Deng, W., Han, W., Lo, N., Cai, J., Che, Y. & Wang, Z. (2025) Revision of the cockroach subfamily Blattinae based on morphological and molecular analyses. Systematic Entomology, 50, 1–19. https://doi.org/10.1111/syen.12680
- Miralles, A., Ducasse, J., Brouillet, S., Flouri, T., Fujisawa, T., Kapli, P., Knowles, L.L., Kumari, S., Stamatakis, A., Sukumaran, J. & Lutteropp, S. (2022) SPART: A versatile and standardized data exchange format for species partition information. Molecular Ecology Resources, 22 (1), 430–438. https://doi.org/10.1111%2F1755-0998.13470
- Prabakaran, S., Senraj, M. & Lucanas, C. (2019) A new species of Allacta Saussure & Zehntner 1895 (Blattodea: Ectobiidae: Pseudophyllodromiinae) from India. Halteres, 10, 1–6. https://doi.org/10.5281/zenodo.2620772
- Puillandre, N., Lambert, A., Brouillet, S. & Achaz, G. (2012) ABGD, Automatic Barcode Gap Discovery for primary species delimitation. Molecular Ecology, 21 (8), 1864–1877. https://doi.org/10.1111/j.1365-294X.2011.05239.x
- Puillandre, N., Brouillet, S. & Achaz, G. (2021) ASAP: assemble species by automatic partitioning. Molecular Ecology Resources, 21 (2), 609–620. https://doi.org/10.1111/1755-0998.13281
- QGIS Development Team. (2020) QGIS Geographic Information System. Open Source Geospatial Foundation. Available from: https://www.qgis.org (accessed 30 September 2025)
- Ronquist, F. & Huelsenbeck, J.P. (2003) MrBayes 3: Bayesian phylogenetic inference under mixed models. Bioinformatics, 19, 1572–1574. https://doi.org/10.1093/bioinformatics/btg180
- Roth, L.M. (1979) A taxonomic revision of the Panesthiinae of the world. II. The genera Salganea Stål, Microdina Kirby and Caeparia Stål (Dictyoptera: Blattaria: Blaberidae). Australian Journal of Zoology, Supplementary Series, 27 (69), 1–201. https://doi.org/10.1071/AJZS069
- Roth, L.M. (2003) Systematics and phylogeny of cockroaches (Dictyoptera: Blattaria). Oriental Insects, 37 (1), 1–186. https://doi.org/10.1080/00305316.2003.10417344
- Rust, J., Singh, H., Rana, R.S., McCann, T., Singh, L., Anderson, K., Sarkar, N., Nascimbene, P.C., Stebner, F., Thomas, J.C. & Solórzano Kraemer, M. (2010) Biogeographic and evolutionary implications of a diverse paleobiota in amber from the early Eocene of India. Proceedings of the National Academy of Sciences, 107 (43), 18360–18365. https://doi.org/10.1073/pnas.1007407107
- Sahu, A., Singh, M., Laxmi, R.K., Shah, T.K. & Sharma, M. (2025) Environmental DNA (eDNA): an eco-friendly approach for conservation of Indian freshwater diversity—A review. Environmental Science and Pollution Research, 32, 1–28. https://doi.org/10.1007/s11356-025-36202-z
- Senraj, M., Babu, R. & Subramanian, K.A. (2025) New record of the genus Anaplectoidea Shelford, 1906 (Blattodea: Pseudophyllodromiidae: Anaplectoidinae) from India, with description of two new species. Zootaxa, 5693 (3), 423–431. https://doi.org/10.11646/zootaxa.5693.3.7
- Senraj, M., Packiam, S.M., Prabakaran, S., Lucanas, C. & Jaiswal, D. (2021) Review of Indian Allacta Saussure & Zehntner, 1895 (Blattodea: Ectobiidae: Pseudophyllodromiinae), with description of three new species. Zootaxa, 4920 (2), 254–266. https://doi.org/10.11646/zootaxa.4920.2.6
- Shabnam, A., Senraj, M., Shikalgar, S., Morey, R. & Dinesh, K.P. (2026) Revisiting Neoloboptera Princis, 1953 (Blattodea: Blattellidae) with a new species description from the agroecosystem of Peninsular India. Records of the Zoological Survey of India, 126 (1), 1–11. https://doi.org/10.26515/rzsi/v126/i1/2026/173026
- Shabnam, A., Morey, R.A. & Dinesh, K.P. (2025) From serendipity to systematics: tracing the trails of cockroach research in India. Zootaxa, 5661 (4), 521–537. https://doi.org/10.11646/zootaxa.5661.4.3
- Shabnam, A., Morey, R.A. & Dinesh, K.P. (2023) The role of DNA barcodes as a tool to expedite the faunal documentation from a biodiversity hotspot in the Western Ghats, India. In: Advances in Environmental Research, Volume 96. Nova Science Publishers, Inc., New York, pp. 185–200.
- Shabnam, A. & Dinesh, K.P. (2022) DNA barcode for the parthenogenetic Surinam cockroach Pycnoscelus surinamensis (Linnaeus, 1758) (Blattodea: Blaberidae) from India. International Research Journal of Insect Sciences, 7 (1), 1–7. https://doi.org/10.18488/irjis.v7i1.2895
- Singh, N. (2025) Taxonomy in trouble—An impediment to life on Earth. Zootaxa, 5642 (3), 295–300. https://doi.org/10.11646/zootaxa.5642.3.8
- Tamura, K., Stecher, G. & Kumar, S. (2021) MEGA11: Molecular Evolutionary Genetics Analysis version 11. Molecular Biology and Evolution, 38, 3022–3027. https://doi.org/10.1093/molbev/msab120
- ter Schure, A.T., Pillai, A.A., Thorbek, L., Shankar, M.B., Puri, R., Ravikanth, G., de Boer, H.J. & Boessenkool, S. (2021) eDNA metabarcoding reveals dietary niche overlap among herbivores in an Indian wildlife sanctuary. Environmental DNA, 3 (3), 681–696. https://doi.org/10.1002/edn3.168
- Walker, F. (1868) Catalogue of the specimens of Blattariae in the collection of the British Museum. Printed for the Trustees of the British Museum, London, 239 pp. https://doi.org/10.5962/bhl.title.118688
- Walker, F. (1871) Supplement to the catalogue of the Blattariae in the collection of British Museum. Printed for the Trustees of the British Museum, London, 41 pp. [pp. 3–43]
- Wang, Z., Shi, Y., Qiu, Z., Che, Y. & Lo, N. (2017) Reconstructing the phylogeny of Blattodea: robust support for interfamilial relationships and major clades. Scientific Reports, 7 (1), 1–8. https://doi.org/10.1038/s41598-017-04243-1
- Yang, R., Wang, Z., Zhou, Y., Wang, Z. & Che, Y. (2019) Establishment of six new Rhabdoblatta species (Blattodea, Blaberidae, Epilamprinae) from China. ZooKeys, 851, 27–69. https://doi.org/10.3897/zookeys.851.31403
- Zhang, J., Kapli, P., Pavlidis, P. & Stamatakis, A. (2013) A general species delimitation method with applications to phylogenetic placements. Bioinformatics, 29 (22), 2869–2876. https://doi.org/10.1093/bioinformatics/btt499
