Catalpa sphinx moth - Ask Extension
Are sphinx moths a problem for Northern/Western Catalpas in Colorado? Most resources we found about the moths are from other regions of the country.
Knowledgebase
Catalpa sphinx moth #926224
Asked March 18, 2026, 11:04 AM EDT
Are sphinx moths a problem for Northern/Western Catalpas in Colorado? Most resources we found about the moths are from other regions of the country.
Arapahoe County Colorado
Expert Response
Hi Hilary,
No, they are not. The Catalpa Sphinx (Ceratomia catalpae) does not occur this far out west, apart from only 2 historical records.
Thank you for the information about the moth. We also wanted to ask how much water a catalpa needs per month and per year to be a successful thriving tree?
Matthew Noe, RA
Matthew Noe, RA
On Mar 18, 2026, at 2:02 PM, Ask Extension wrote:
A tree's water requirement varies with tree age, site, grade, soil type, and natural precipitation. The rule of thumb is 10 gallons of water per inch of tree diameter per month. This requirement is fulfilled in part by ground water and precipitation. Once established, catalpas can be relatively drought tolerant, only requiring supplemental irrigation during extended dry periods.
https://extension.colostate.edu/resource/fall-and-winter-watering-of-plants-and-trees/
