Large Water Strider (Ptilomera tigrina) —First Field Documentation from Pakistan |Margalla Foothills

This video presents field documentation of the Large Water Strider (Ptilomera tigrina Uhler, 1860) recorded from a fast-flowing freshwater stream in the Margalla Foothills, Islamabad Capital Territory, Pakistan, filmed on 17 August 2024.

The species was observed actively skating on turbulent running water, capturing insect prey and engaging in intra-specific competitive interactions.
Based on body size, coloration, and behavior, both a large adult male and a smaller presumed female were documented moving together on the stream surface, consistent with sexual size dimorphism reported in Ptilomerinae.

⚠️ Important note:
This documentation represents field-based photographic and video evidence only. Species-level identification is supported by comparative morphology and behavior, but no specimens were collected. The plan exists to explore this at deeper level.

This record highlights the under-documented semi-aquatic insect fauna of Pakistan and demonstrates how field videography can contribute to biodiversity knowledge, especially for taxa that are difficult to sample.

📍 Location: Margalla Foothills, Islamabad, Pakistan
📅 Date: 17 August 2024
🎥 Camera: Sony digital camera (handheld field videography)
Music: YouTube Audio Library

More detailed taxonomic discussion and figures will be shared through BiodiversiGrapher® upcoming website: www.biodiversigrapher.com.

References
• Jehamalar, E.E. et al. (2018). Review of Ptilomera (Ptilomera) from India. Zootaxa 4370(5): 501–518.
• Polhemus, D.A. (2001). Review of Ptilomera from Indochina. J. NY Entomol. Soc.
• Andersen, N.M. (1990). Phylogeny and taxonomy of water striders.
• Cianferoni et al. (2018). Gerridae of Pakistan — checklist and distribution.

If you value field-based biodiversity documentation, support BiodiversiGrapher® by:
• 👍 Liking the video
• 🔔 Subscribing to the channel
• 💬 Sharing insights or comparative records from South Asia