A new species of Homophylax from the Sierra Nevada mountains
Faculty Mentor Name
Dr. Ryan Hill
Research or Creativity Area
Natural Sciences
Abstract
The caddisflies (order Trichoptera) are a group of insects whose larvae are useful bioindicators because they are relatively intolerant to organic pollution. In California, 358 caddis species are known to occur, and this number will likely increase as museum material is reviewed, new records are found, and undescribed species are documented. As part of efforts to understand how the caddisfly fauna has changed over the past 40 years in the Sagehen Creek Experimental Forest, field collections were made using blacklights and emergence traps. In order to document changes through time, several species required review of the literature for name changes and descriptions of new species. Of the 80+ species collected, all species names have been reconciled with the literature and morphological study, except one listed as “Homophylax sp.” in the historical work. Samples of this same species were collected in our re-survey but do not match any described species. This study seeks to clarify the status of the Homophylax species in the Sagehen Creek basin through comparative analysis of morphology and mitochondrial DNA. Our study of samples collected between 2023-2025 clearly indicate Homphylax rentzi is still present in the basin, and that the historically identified Homophylax sp. differs from other described species in its combination of characters involving the tibial spur formula, forewing color pattern, presence of forewing flap and genitalia. Analysis of mitochondrial DNA, including many putatively new species in western North America indicates that Homophylax sp. is genetically distinct from described and undescribed taxa. Together the evidence points very strongly to this population being an undescribed species in need of description.
A new species of Homophylax from the Sierra Nevada mountains
The caddisflies (order Trichoptera) are a group of insects whose larvae are useful bioindicators because they are relatively intolerant to organic pollution. In California, 358 caddis species are known to occur, and this number will likely increase as museum material is reviewed, new records are found, and undescribed species are documented. As part of efforts to understand how the caddisfly fauna has changed over the past 40 years in the Sagehen Creek Experimental Forest, field collections were made using blacklights and emergence traps. In order to document changes through time, several species required review of the literature for name changes and descriptions of new species. Of the 80+ species collected, all species names have been reconciled with the literature and morphological study, except one listed as “Homophylax sp.” in the historical work. Samples of this same species were collected in our re-survey but do not match any described species. This study seeks to clarify the status of the Homophylax species in the Sagehen Creek basin through comparative analysis of morphology and mitochondrial DNA. Our study of samples collected between 2023-2025 clearly indicate Homphylax rentzi is still present in the basin, and that the historically identified Homophylax sp. differs from other described species in its combination of characters involving the tibial spur formula, forewing color pattern, presence of forewing flap and genitalia. Analysis of mitochondrial DNA, including many putatively new species in western North America indicates that Homophylax sp. is genetically distinct from described and undescribed taxa. Together the evidence points very strongly to this population being an undescribed species in need of description.
