{"id":270,"date":"2026-08-05T15:28:48","date_gmt":"2026-08-05T19:28:48","guid":{"rendered":"https:\/\/site.extension.uga.edu\/irwinag\/?p=270"},"modified":"2026-08-05T15:28:48","modified_gmt":"2026-08-05T19:28:48","slug":"cotton-silverleaf-whiteflies-and-jassid-update","status":"publish","type":"post","link":"https:\/\/site.extension.uga.edu\/irwinag\/2026\/08\/cotton-silverleaf-whiteflies-and-jassid-update\/","title":{"rendered":"Cotton \u2013 Silverleaf Whiteflies and Jassid Update"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Silverleaf Whitefly Management by: (Phillip Roberts and Alana Jacobson): <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The initial goal of a successful<br>silverleaf whitefly (SLWF) management is to lower the risk of whitefly infestations. All efforts should be<br>made to minimize the need to treat SLWF with insecticides. Following the guidelines below, especially<br>when done on a community basis, should result in reduced risk of SLWF locally and areawide.<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Destroy host crops immediately after harvest; this includes vegetable and melon crops in the<br>spring and cotton (timely defoliation and harvest) and other host crops in the fall.<\/li>\n\n\n\n<li>Scout cotton on a regular basis for SLWF adults and immatures and use recommended thresholds.<\/li>\n\n\n\n<li>The presence of SLWF should influence insecticide selection and the decision to treat other pests.<\/li>\n\n\n\n<li>Conserve beneficial insects; do not apply insecticides for ANY pests unless thresholds are<br>exceeded.<\/li>\n\n\n\n<li>Avoid use of insecticides for other pests which are prone to flare SLWF.<br>Several additional factors influence SLWF risk:<\/li>\n\n\n\n<li>Leaf pubescence: SLWF prefers hairy cotton. The more leaf pubescence the greater the SLWF risk<br>(semi-smooth varieties are at higher risk than smooth leaf varieties).<\/li>\n\n\n\n<li>Planting Date: late planted cotton is at greater risk compared with early planted cotton. This is<br>simply a numbers game as overall SLWF populations increase during the summer months.<\/li>\n\n\n\n<li>Environment: hot and dry conditions are conducive for SLWF population growth. Intense rainfall<br>associated with thunderstorms can provide suppression of adults. Extended periods of rainfall will<br>also slow down population growth.<br>As many of you are aware, we and several agents run whitefly sticky cards around Tifton to monitor<br>SLWF populations. We update the website below weekly with trap captures:<br>https:\/\/stopwhitefly.org\/monitoring\/<br>Invariably there will be fields which require intervention of insecticides for SLWF. The goal is to initiate<br>control measures just prior to the period of most rapid SLWF population development (i.e. reproduction in<br>the field). It is critically important that initial insecticide applications are well timed. If you are late with<br>the initial application control will be very difficult and expensive in the long run. It is nearly impossible to<br>regain control once the population reaches outbreak levels.<\/li>\n\n\n\n<li>SLWF Threshold: Treat when 50 percent of sampled leaves (sample 5th expanded leaf below the<br>terminal) are infested with multiple immatures (\u22655 per leaf).<\/li>\n\n\n\n<li>Insect Growth Regulators (Knack and Courier): use of IGRs are the backbone of SLWF<br>management programs in cotton. Effects on SLWF populations are generally slow due to the life<br>stages targeted by IGRs, however these products have long residual activity and perform very well<br>when applied on a timely basis.<\/li>\n\n\n\n<li>Use of other insecticide options (non-IGRs) which have quicker effects on SLWF infestations<br>would be preferred if you are late with the initial spray. These quick knockdown sprays will allow<br>you to \u201ccatch up\u201d and can be followed by an IGR.<\/li>\n\n\n\n<li>SLWF is an areawide cross commodity problem. When everyone uses an effective management<br>program (regardless of crop) all will benefit.<br>The table below provides some general information on SLWF recommended insecticide<br><\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"575\" height=\"450\" src=\"https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-8.png\" alt=\"\" class=\"wp-image-271\" srcset=\"https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-8.png 575w, https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-8-300x235.png 300w\" sizes=\"auto, (max-width: 575px) 100vw, 575px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Cotton Jassid Update <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">(Phillip Roberts and Alana Jacobson): We are in a better position today<br>concerning cotton jassid compared to where we were a year ago. To date we have detected jassids in 16<br>counties in 2026. This time a year ago (August 7, 2025) we had detected jassids in 33 counties. Jassid<br>populations where we detected them a year ago were also present at much higher populations than now.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Thanks to our agents and others in the industry who have been letting us know when and where jassids<br>are detected. We maintain a map of jassid detections online at: https:\/\/stop2scl.org\/cotton\/<br>There is no question that the cold temperatures significantly reduced jassids across Georgia. In February a<br>hard freeze occurred over most of Florida that likely reduced jassid populations to the southernmost part<br>of Florida. Initial detections were likely migrating adults which moved in on wind currents. Perhaps 2026<br>is a best case scenario for jassid as we move forward, but who knows.<br>We have received a few reports of early hopperburn on field edges and skips in fields. As we move<br>forward scouting is a must and we should all be looking for hopperburn and leaf puckering symptoms. We<br>did receive a report today (August 4th) that a field exceeded threshold for jassid in southeast Georgia. In<br>2025 the first commercial field treated for jassids was on July 31st but at that time our threshold was much<br>higher than the 1 jassid per leaf threshold we are recommending for 2026<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"405\" height=\"417\" src=\"https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-10.png\" alt=\"\" class=\"wp-image-272\" srcset=\"https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-10.png 405w, https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-10-291x300.png 291w\" sizes=\"auto, (max-width: 405px) 100vw, 405px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 2 Jassid Hopperburn<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 3 below  Adult cotton jassid with shed skin to the right,<br>image by Jeremy Kichler<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"591\" height=\"374\" src=\"https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-9.png\" alt=\"\" class=\"wp-image-273\" srcset=\"https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-9.png 591w, https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-9-300x190.png 300w\" sizes=\"auto, (max-width: 591px) 100vw, 591px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">When scouting for jassids examine the 4th expanded main stem leaf below the terminal. Sample this leaf<br>on a minimum of 25 plants per field (sampling more leaves is better). If jassids reach a mean of 1 jassid<br>per leaf treatment is recommended. Once the threshold is triggered it will be important to make a timely<br>application. As we learned in 2025, jassid numbers and plant injury can progress quickly. If a grower<br>struggles to be timely with an application, you may need to be more aggressive if populations are building. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The chart below is a general guide of expected efficacy of insecticides we tested in the southeast<br>during 2025. Some insecticides were tested more than others (i.e. Carbine has 9 data points, Venom only<br>has 2 data points) so we cannot make direct comparisons. But this chart does have some value. I interpret<br>this chart that insecticides highlighted in green would be used if jassids triggered threshold. Products in<br>orange provide suppression but may be of value if a grower cannot come back and make a timely<br>application based on scouting. It is also important to note that bifenthrin will not provide control of<br>jassids. Don\u2019t overreact when you detect jassids, scout and use thresholds, and watch trends of how fast<br>populations are building. All this will allow you to make a good decision. As in 2025 we will provide<br>updates of the most current information to county agents.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"751\" height=\"540\" src=\"https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-11.png\" alt=\"\" class=\"wp-image-274\" srcset=\"https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-11.png 751w, https:\/\/site.extension.uga.edu\/irwinag\/files\/2026\/08\/image-11-300x216.png 300w\" sizes=\"auto, (max-width: 751px) 100vw, 751px\" \/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Silverleaf Whitefly Management by: (Phillip Roberts and Alana Jacobson): The initial goal of a successfulsilverleaf whitefly (SLWF) management is to lower the risk of whitefly infestations. All efforts should bemade to minimize the need to treat SLWF with insecticides. Following the guidelines below, especiallywhen done on a community basis, should result in reduced risk of [&hellip;]<\/p>\n","protected":false},"author":234,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-270","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/site.extension.uga.edu\/irwinag\/wp-json\/wp\/v2\/posts\/270","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/site.extension.uga.edu\/irwinag\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/site.extension.uga.edu\/irwinag\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/site.extension.uga.edu\/irwinag\/wp-json\/wp\/v2\/users\/234"}],"replies":[{"embeddable":true,"href":"https:\/\/site.extension.uga.edu\/irwinag\/wp-json\/wp\/v2\/comments?post=270"}],"version-history":[{"count":1,"href":"https:\/\/site.extension.uga.edu\/irwinag\/wp-json\/wp\/v2\/posts\/270\/revisions"}],"predecessor-version":[{"id":275,"href":"https:\/\/site.extension.uga.edu\/irwinag\/wp-json\/wp\/v2\/posts\/270\/revisions\/275"}],"wp:attachment":[{"href":"https:\/\/site.extension.uga.edu\/irwinag\/wp-json\/wp\/v2\/media?parent=270"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/site.extension.uga.edu\/irwinag\/wp-json\/wp\/v2\/categories?post=270"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/site.extension.uga.edu\/irwinag\/wp-json\/wp\/v2\/tags?post=270"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}