The City is experiencing an increase in the amount of secretion producing pests from trees in our City parks and landscaped right-of-ways. As a result of the very wet winter we experienced last year, the amount of vegetation has increased tremendously, resulting in prime habitat for leaf sucking insects like aphids. When aphids feed, they inject saliva into their host plant to help digest the sap.

After feeding, they secrete a sticky, shiny waste product called honeydew. Honeydew is a sugar-rich material that attracts ants, yellow jackets (especially during late summer and fall) and other insects that feed on it. Most people refer to this honeydew as “sap”. This year, in particular, has been a very bad year for aphids and we are experiencing the infestations City-wide, mostly in the Hackberry, Crape Myrtle and Chinese Elm trees. This is not to say other varieties of trees are not being effected, but we are predominately seeing the aforementioned trees affected the most. Orchard Park, Veterans Park, and Walnut Park are just a few of the most affected parks, while Balfour Road, Spruce Street, Fairview Avenue and Minnesota Avenue are some of the affected right-of-way areas.

Staff is very much aware of the issue and working closely with City contractors to help remedy the pest issues. Parks Staff have been power washing parks, sidewalks, shade covers, play equipment and other amenities in our parks on a regular basis trying to rid the nuisance of this sticky liquid. Cooler temperatures and wet weather in the near future will also aid in the control of the pests.

If residents are experiencing similar issues with their privately maintained trees, we recommend they contact a local pest control company to better assess their individual issue and properly identify the exact pest. Power washing or a high pressure nozzle on a hose can help wash the secretions off of sidewalks and other surfaces. Local nurseries and the UC Cooperative Extension can also provide additional information on pests associated with trees and plant material. https://ucanr.edu/sites/ucanr/County_Offices/