- Author: Sandipa Gautam
Sandipa Gautam, Area Citrus IPM Advisor serving Kern, Tulare, Fresno, and Madera counties has been maintaining a web page on the Lindcove Website Citrus IPM - Lindcove Research and Extension Center (ucanr.edu). Within this page, she writes a blog on pest issues that are problem for growers in the SJV region. For subscribing, click https://ucanr.edu/blogs/IPMBlog/ and enter your email address. You will receive an email to confirm subscription, follow the instructions to complete subscription. Every time a post is made you will receive and email notification. This page also hosts pest memos of this season and archives from the previous season along with links to Citrus related extension posts, newsletters.
Within the Citrus IPM tab, you will also find Degree Days, which is regularly updated for California red scale for four counties in the SJV. If you are in Ventura county or other citrus growing counties (not in the valley) and California red scale is a pest you manage and are interested in Degree Day calculation and predictions, please contact sangautam@Ucanr.edu .
If you would like to receive emails on pest memos/other events, please send an email to sangautam@ucanr.edu to be added to her email list.
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The sticky substance is called honeydew. The honeydew is excreted by a number of sap-sucking insects such as aphids, whiteflies, mealybugs, certain scale insects, and few others. On hackberry trees (widely planted in some cities), an insect called the woolly hackberry aphid produces a large amount of honeydew.
If you examine the tree's leaves, you may see bluish-white masses that are actually this insect in disguise, coated in a pale wax that makes them appear fuzzy. In addition to the mess caused by the honeydew, you may also notice a black, sooty mold growing on the leaves. Although honeydew and sooty mold can be a nuisance, no long-term or serious damage to hackberry trees has been found, even after years of aphid infestations.
To learn more about the woolly aphid, see the UC IPM Pest Notes: Hackberry Woolly Aphid. If the sticky tree you park under is your own, the Pest Notes will help you find solutions to manage the aphid population should you choose to do so.
Other shade trees can also get different types of aphids, scales, and other honeydew-producing pests. Find information about these other plant sucking pests and their damage and management at http://ipm.ucanr.edu/PMG/invertebrates/menu.aphidsthrips.html.