{"id":8339,"date":"2026-09-10T07:58:00","date_gmt":"2026-09-10T13:58:00","guid":{"rendered":"https:\/\/extension.colostate.edu\/arapahoe\/?p=8339"},"modified":"2026-09-09T15:49:59","modified_gmt":"2026-09-09T21:49:59","slug":"from-the-hort-desk","status":"publish","type":"post","link":"https:\/\/extension.colostate.edu\/arapahoe\/2026\/09\/10\/from-the-hort-desk\/","title":{"rendered":"From the Hort Desk"},"content":{"rendered":"\n<div class=\"wp-block-group c-breadcrumbs alignfull is-layout-flow wp-block-group-is-layout-flow\" style=\"margin-top:var(--wp--preset--spacing--40);margin-bottom:var(--wp--preset--spacing--40)\">\n<div class=\"wp-block-group container is-layout-flow wp-block-group-is-layout-flow\"><nav aria-label=\"breadcrumbs\" class=\"rank-math-breadcrumb\"><p><span class=\"last\">Home<\/span><\/p><\/nav>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-group is-layout-constrained wp-container-core-group-is-layout-ffae927d wp-block-group-is-layout-constrained\" style=\"padding-top:var(--wp--preset--spacing--30);padding-bottom:var(--wp--preset--spacing--30)\">\n<h1 class=\"wp-block-heading\">From the Hort Desk<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>The Buggy Bulletin \u2013 2026 Notes on Pests, Pathogens and Drought<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">By Lisa Mason, CSU Extension Horticulture Specialist, Entomologist<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Following a record-breaking winter with little moisture and warm temperatures, Colorado continues to experience hot and dry weather. While some areas have seen recent rain, Colorado is still largely in a drought statewide. The reservoirs are at record-low levels, water restrictions remain in place, and Coloradans need to be mindful about their own water use, especially in the landscape. For current drought updates, visit <a href=\"https:\/\/climate.colostate.edu\/drought_info.html\" target=\"_blank\" rel=\"noopener\"><strong>CSU\u2019s Colorado Climate Center website<\/strong><\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>How do drought and hot temperatures influence pests and plants?<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Insect populations ebb and flow from year to year, and fluctuations are normal. Weather patterns often influence insect populations and plant growth. Generally, moisture is great for plant growth and health. A healthier plant can withstand more damage from certain pests like Japanese beetles. More moisture can promote the growth of weedy plants which can provide more food for grasshoppers. This puts less feeding pressure on crops and ornamental plants. Without moisture, plants may experience more stress from the environment, pests and pathogens. Many insects thrive in hot weather, including Japanese beetles and grasshoppers. The hotter, drier summers we are experiencing can also promote insects that impact human health. While ticks go dormant in the high heat, the warmer spring and fall weather provide a longer season for ticks to be active, potentially increasing the risk of disease.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Here are some of the notable pests and pathogens observed this summer:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Emerald Ash Borer<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Emerald ash borer (EAB) continues to spread throughout the Denver Metro Area. Most recently, EAB has been confirmed in Parker and Colorado Springs, which is the first time we\u2019ve seen EAB in Douglas and El Paso counties. EAB has also been confirmed in Ken Caryl in Jefferson County and Firestone in Weld County. New confirmations will continue to happen as EAB naturally spreads each year and if people bring infested firewood to new areas.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">EAB is an invasive beetle that kills all ash trees in the <em>Fraxinus<\/em> genus (e.g., white and green ash). If you have an ash tree on your property, you\u2019ll have to make a financial decision on whether to save or remove the tree. All trees will eventually need to be treated with insecticide if they are to be saved. Many factors impact the decision to save or remove a tree, and when to take action. For treatment options and more information, <a href=\"https:\/\/arapahoeco.gov\/eab\" target=\"_blank\" rel=\"noopener\"><strong>click here<\/strong><\/a>. For questions on EAB, or how to make decisions about your trees and possible diagnosis, contact CSU Extension Arapahoe County at <a href=\"mailto:MasterGardener@arapahoegov.com\"><strong>MasterGardener@arapahoegov.com<\/strong><\/a> or 303-730-1920.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"768\" height=\"417\" src=\"https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/5473689_Credit_LeahBauer_USDAFS_Bugwood.jpg\" alt=\"slender irridescent green insect\" class=\"wp-image-8340\" style=\"aspect-ratio:1.8417581594034549;object-fit:cover;width:350px\" srcset=\"https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/5473689_Credit_LeahBauer_USDAFS_Bugwood.jpg 768w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/5473689_Credit_LeahBauer_USDAFS_Bugwood.jpg?resize=300,163 300w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/5473689_Credit_LeahBauer_USDAFS_Bugwood.jpg?resize=600,326 600w\" sizes=\"auto, (max-width: 768px) 100vw, 768px\" \/><figcaption class=\"wp-element-caption\"><em>An adult emerald ash borer. Photo: Leah Bauer, USDA Forest Service, <\/em><a href=\"http:\/\/www.bugwood.org\" target=\"_blank\" rel=\"noopener\"><em><strong>www.bugwood.org<\/strong><\/em><\/a><\/figcaption><\/figure>\n\n\n\n<div style=\"height:21px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Rose Rosette Disease<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Last summer, rose rosette disease was confirmed in Boulder, Colorado. This summer it has been confirmed in one location in Larimer County. This disease is a rare occurrence but has been documented in the Rocky Mountains. It impacts both wild and cultivated species of rose plants (<em>Rosa<\/em> spp.). Multiflora rose (<em>Rosa multiflora<\/em>) is a common host plant. Unfortunately, there is no cure for the disease and rose gardeners should learn to recognize the symptoms to limit spread. The disease is spread via flightless eriophyid mites that are carried in the wind, on gardening tools, and even on the clothes of a gardener. Learn more about it <a href=\"https:\/\/extension.okstate.edu\/fact-sheets\/rose-rosette-disease\" target=\"_blank\" rel=\"noopener\"><strong>here<\/strong><\/a>. Symptomatic plants should be sent to the CSU Plant Diagnostic Lab at the CSU Spur campus.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Asian Jumping Worm<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Asian jumping worm (AJW) was confirmed in Denver\u2019s Hilltop neighborhood in October 2025. AJW is in a group of invasive worms that quickly consume organic matter and degrade the soil in the landscape. If the soil in your garden or landscape suddenly has texture like coffee grounds, consider collecting worms and sending in a sample to the Colorado Department of Agriculture. AJW is extremely hard to control and no eradication methods exist. Prevention of spread is key. Learn more about AJW <a href=\"https:\/\/ag.colorado.gov\/plants\/pest-survey\/asian-jumping-worm\" target=\"_blank\" rel=\"noopener\"><strong>here<\/strong><\/a>.&nbsp;<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Miller Moths<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Miller moths, also known as army cutworm moths, migrate from the eastern plains to the high-elevation Rocky Mountains to spend the summer months in cooler weather. The miller moths then migrate back to the eastern plains in the fall, though the migration back usually is not noticeable to people.&nbsp; Miller moths can become a nuisance for humans when they stop along the Front Range to take full advantage of the nectar in flowering plants found in irrigated landscapes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Miller moths were lower in numbers than average this year. The population of moths and the length of time they spend on the Front Range depend on the number of moths migrating from the eastern plains, caterpillar host plant availability, food availability (nectar flowers) along the Front Range, and the weather. While there were lower numbers this season, it is possible the moths also moved on quickly from the Front Range to escape the hot temperatures and to find flowers at higher elevations.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" height=\"768\" width=\"1024\" src=\"https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Miller-moth-4-high-rez-Credit-Lisa-Mason-CSU-Extension.jpg?w=1024\" alt=\"brown moths with textured looking wings\" class=\"wp-image-8341\" style=\"aspect-ratio:1.3333473577919892;object-fit:cover;width:350px\" srcset=\"https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Miller-moth-4-high-rez-Credit-Lisa-Mason-CSU-Extension.jpg 4032w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Miller-moth-4-high-rez-Credit-Lisa-Mason-CSU-Extension.jpg?resize=300,225 300w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Miller-moth-4-high-rez-Credit-Lisa-Mason-CSU-Extension.jpg?resize=768,576 768w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Miller-moth-4-high-rez-Credit-Lisa-Mason-CSU-Extension.jpg?resize=1024,768 1024w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Miller-moth-4-high-rez-Credit-Lisa-Mason-CSU-Extension.jpg?resize=1536,1152 1536w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Miller-moth-4-high-rez-Credit-Lisa-Mason-CSU-Extension.jpg?resize=2048,1536 2048w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Miller-moth-4-high-rez-Credit-Lisa-Mason-CSU-Extension.jpg?resize=2000,1500 2000w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Miller-moth-4-high-rez-Credit-Lisa-Mason-CSU-Extension.jpg?resize=1400,1050 1400w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Miller-moth-4-high-rez-Credit-Lisa-Mason-CSU-Extension.jpg?resize=600,450 600w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Miller-moth-4-high-rez-Credit-Lisa-Mason-CSU-Extension.jpg?resize=1568,1176 1568w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\"><em>Miller moths in Arapahoe County. Photo: Lisa Mason<\/em><\/figcaption><\/figure>\n\n\n\n<div style=\"height:21px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Grasshoppers<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Grasshopper populations were variable, depending on the location in Colorado. Generally, warm, dry winters support higher grasshopper populations because they may hatch earlier in the season providing a longer period of time to feed. Less moisture and drought conditions will likely lead to less food availability, meaning grasshoppers can cause more damage to crops and home gardens.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Japanese Beetles<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">With the drought, a big question came to mind for many: Will the dry environment impact Japanese beetle populations?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Japanese beetles are an invasive species in Colorado. They are established in many parts of the Front Range and, unfortunately, they are here to stay. Populations may vary slightly from year to year but generally, Japanese beetles will continue to be a nuisance pest feeding on over 300 types of plants.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Since Japanese beetle grubs need consistently moist soil in turf grass to reproduce, there may be fewer grubs that are able to survive. They will still be able to reproduce in areas where the turf grass stays consistently moist, but with watering restrictions, there may be less available space for them. While we can hope for fewer numbers next year, they will likely still be around.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When managing grubs in the lawn, consider letting your lawn dry between waterings. This will ensure grubs cannot survive since they need consistently moist turf grass to complete development. If you have brown spots in the lawn, try an irrigation audit or contact your Extension office for assistance. Brown spots in the lawn can indicate a variety of issues other than grubs, including non-uniform irrigation coverage and\/or drought stress. If grubs are present in the lawn, there are a variety of treatment options available. Refer to the <a href=\"https:\/\/extension.colostate.edu\/resource\/japanese-beetle\/\"><strong>Japanese Beetle Fact Sheet<\/strong><\/a>. Remember, seeing adults in your yard doesn\u2019t mean they are nesting in your turf grass.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Long-term solutions for managing Japanese beetles include finding alternative plants or different varieties of plants that are not preferred by the beetles. This is often a personal choice but there is a wealth of plant options available.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large is-resized\"><img loading=\"lazy\" decoding=\"async\" height=\"1024\" width=\"768\" src=\"https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/JB-1-on-sunflower-Credit-Lisa-Mason.jpg?w=768\" alt=\"irridescent brown and green insect on yellow flower\" class=\"wp-image-8342\" style=\"aspect-ratio:0.7507293305432939;width:350px\" srcset=\"https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/JB-1-on-sunflower-Credit-Lisa-Mason.jpg 1318w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/JB-1-on-sunflower-Credit-Lisa-Mason.jpg?resize=225,300 225w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/JB-1-on-sunflower-Credit-Lisa-Mason.jpg?resize=768,1024 768w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/JB-1-on-sunflower-Credit-Lisa-Mason.jpg?resize=1152,1536 1152w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/JB-1-on-sunflower-Credit-Lisa-Mason.jpg?resize=600,800 600w\" sizes=\"auto, (max-width: 768px) 100vw, 768px\" \/><figcaption class=\"wp-element-caption\"><em>A Japanese beetle on a sunflower in Arapahoe County. Photo: Lisa Mason<\/em><\/figcaption><\/figure>\n\n\n\n<div style=\"height:21px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Forests Pests<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">From a statewide perspective, many pests continue to impact forests in Colorado. Bark beetles, which are lethal to trees, continue to be an issue in pockets around Colorado. Mountain pine beetle activity has increased significantly in ponderosa pine in the foothills of the Front Range. Ips beetles also continue to be present in both forests and urban\/suburban areas in the Front Range. Different species of ips can impact spruce trees and pine trees.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Conifer trees are also experiencing drought stress. If you have conifer trees in decline on your property, diagnosis is key due to different management strategies that might be needed depending on the cause of decline. For example, high-value drought-stressed trees require supplemental water all year around. To learn more about <a href=\"https:\/\/csfs.colostate.edu\/forest-management\/common-forest-insects-diseases\/mountain-pine-beetle\/\" target=\"_blank\" rel=\"noopener\"><strong>mountain pine beetle<\/strong><\/a>, <a href=\"https:\/\/csfs.colostate.edu\/forest-management\/common-forest-insects-diseases\/ips-beetle\/\" target=\"_blank\" rel=\"noopener\"><strong>ips<\/strong><\/a>, or other forest insects, visit the Colorado State Forest Service <a href=\"https:\/\/csfs.colostate.edu\/\" target=\"_blank\" rel=\"noopener\"><strong>website<\/strong><\/a>.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"865\" height=\"939\" src=\"https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Grasshopper-nymph-on-hollyhock-at-my-house-Credit-Lisa-Mason.jpg\" alt=\"brown insect with sturdy legs and striped body\" class=\"wp-image-8345\" style=\"aspect-ratio:0.9212080871952741;width:350px\" srcset=\"https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Grasshopper-nymph-on-hollyhock-at-my-house-Credit-Lisa-Mason.jpg 865w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Grasshopper-nymph-on-hollyhock-at-my-house-Credit-Lisa-Mason.jpg?resize=276,300 276w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Grasshopper-nymph-on-hollyhock-at-my-house-Credit-Lisa-Mason.jpg?resize=768,834 768w, https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/Grasshopper-nymph-on-hollyhock-at-my-house-Credit-Lisa-Mason.jpg?resize=600,651 600w\" sizes=\"auto, (max-width: 865px) 100vw, 865px\" \/><figcaption class=\"wp-element-caption\"><em>A grasshopper nymph on hollyhock in Arapahoe County. <em>May is the most effective time to manage grasshopper  <\/em>nymphs because they are limited in their mobility. Photo: Lisa Mason<\/em><\/figcaption><\/figure>\n\n\n\n<div style=\"height:21px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Learn More about Pests and Management Strategies<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If you have questions about pests in your landscape, reach out to the Arapahoe County Extension office. Call 303-730-1920 or email the Master Gardener Help Desk at <a href=\"mailto:MasterGardener@arapahoegov.com\"><strong>MasterGardener@arapahoegov.com<\/strong><\/a>.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>From the Hort Desk The Buggy Bulletin \u2013 2026 Notes on Pests, Pathogens and Drought By Lisa Mason, CSU Extension Horticulture Specialist, Entomologist Following a record-breaking winter&#8230;<\/p>\n","protected":false},"author":185,"featured_media":8340,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":true},"class_list":["post-8339","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry"],"pp_statuses_selecting_workflow":false,"pp_workflow_action":"current","pp_status_selection":"publish","pp_force_visibility":null,"pp_subpost_visibility":null,"pp_inherited_force_visibility":null,"pp_inherited_subpost_visibility":null,"pp_post_mime_type":"","acf":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/extension.colostate.edu\/arapahoe\/wp-content\/uploads\/sites\/49\/2026\/09\/5473689_Credit_LeahBauer_USDAFS_Bugwood.jpg","_links":{"self":[{"href":"https:\/\/extension.colostate.edu\/arapahoe\/wp-json\/wp\/v2\/posts\/8339","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/extension.colostate.edu\/arapahoe\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/extension.colostate.edu\/arapahoe\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/extension.colostate.edu\/arapahoe\/wp-json\/wp\/v2\/users\/185"}],"replies":[{"embeddable":true,"href":"https:\/\/extension.colostate.edu\/arapahoe\/wp-json\/wp\/v2\/comments?post=8339"}],"version-history":[{"count":7,"href":"https:\/\/extension.colostate.edu\/arapahoe\/wp-json\/wp\/v2\/posts\/8339\/revisions"}],"predecessor-version":[{"id":8401,"href":"https:\/\/extension.colostate.edu\/arapahoe\/wp-json\/wp\/v2\/posts\/8339\/revisions\/8401"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/extension.colostate.edu\/arapahoe\/wp-json\/wp\/v2\/media\/8340"}],"wp:attachment":[{"href":"https:\/\/extension.colostate.edu\/arapahoe\/wp-json\/wp\/v2\/media?parent=8339"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}