[et_pb_section fb_built=”1″ admin_label=”section” module_id=”1″ _builder_version=”4.17.4″ global_colors_info=”{}”][et_pb_row column_structure=”1_2,1_2″ admin_label=”row” _builder_version=”4.16″ background_size=”initial” background_position=”top_left” background_repeat=”repeat” global_colors_info=”{}”][et_pb_column type=”1_2″ _builder_version=”4.16″ custom_padding=”|||” global_colors_info=”{}” custom_padding__hover=”|||”][et_pb_text admin_label=”squiggle-left” _builder_version=”4.27.2″ _module_preset=”default” header_font=”||||||||” header_text_align=”left” header_font_size=”22px” width=”100%” module_alignment=”center” custom_margin=”3%||||false|false” custom_padding=”||||false|false” global_module=”23371″ saved_tabs=”all” global_colors_info=”{}”]<\/p>\n
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Order: Hemiptera
Family: Cicadellidae<\/p>\n
Leafhoppers are generally small, torpedo shaped insects that have long bodies relative to their width, and their hindlegs have one or more rows of spines. Some species are brightly colored while others camouflage with the host plant. Both adults and nymphs are highly mobile and will jump away from physical disturbances.<\/p>\n
In Colorado, the most common leafhopper in hemp is Ceratagallia uhleri<\/em>, which does not cause injury to plants. Ceratagallia <\/em>spp. are typically brown or dark gray with brown markings. Adults of beet leafhopper are pale green in the summer and roughly 3.3-3.6 mm (0.13-0.14 inches) long. There are no markings on the head unlike many other leafhopper species, and this feature can be used to distinguish beet leafhopper from other leafhopper species found in hemp.<\/p>\n [\/et_pb_text][et_pb_blurb title=”Quick Facts” use_icon=”on” font_icon=”||fa||900″ icon_color=”#F15625″ image_icon_width=”36px” _builder_version=”4.21.0″ _module_preset=”default” header_level=”h3″ header_font=”|||on|||||” header_text_align=”center” header_font_size=”26px” background_color=”#FEBD3B” custom_padding=”4%|4%|4%|4%|true|true” global_colors_info=”{}”]<\/p>\n \u2022 Beet leafhoppers\u00a0are small insects in the order Hemiptera. They have piercing-sucking mouthparts and are major pests of sugar beets. It is an important vector of the beet curly top virus (BCTV), which can significantly reduce plant health. [\/et_pb_blurb][et_pb_blurb image=”https:\/\/agsci.colostate.edu\/agbio\/wp-content\/uploads\/sites\/127\/2022\/10\/Beet-leafhopper.jpg” alt=”Beet leafhopper” _builder_version=”4.21.0″ _module_preset=”default” body_line_height=”1.4em” image_icon_custom_margin=”||-22px||false|false” custom_padding=”4%|4%|4%|4%|true|true” border_width_all=”4px” border_color_all=”#F15625″ global_colors_info=”{}”]<\/p>\n Beet leafhopper adult. Beet leafhoppers are small insects in the order Hemiptera. They have piercing-sucking mouthparts and are major pests of sugar beets. Beet leafhoppers are also vectors of the beet curly top virus (BCTV), which is capable of infecting various cultivated plants including hemp. Young plants are the most susceptible to infection and this virus can significantly reduce hemp yields. Management recommendations for beet leafhopper in hemp primarily involve cultural and chemical control. Image credit: A.C. Magyarosy, Bugwood.org<\/em><\/p>\n [\/et_pb_blurb][\/et_pb_column][et_pb_column type=”1_2″ _builder_version=”4.16″ custom_padding=”|||” global_colors_info=”{}” custom_padding__hover=”|||”][et_pb_blurb image=”https:\/\/agsci.colostate.edu\/agbio\/wp-content\/uploads\/sites\/127\/2022\/10\/Nymph-of-Ceratagallia-uhleri.jpg” alt=”Nymph of Ceratagallia uhleri” _builder_version=”4.21.0″ _module_preset=”default” body_line_height=”1.4em” image_icon_custom_margin=”||-22px||false|false” global_colors_info=”{}”]<\/p>\n Nymph of Ceratagallia uhleri <\/em>on a hemp leaf. Image credit: Melissa Schreiner, Colorado State University, Bugwood.org<\/em><\/p>\n [\/et_pb_blurb][et_pb_blurb image=”https:\/\/agsci.colostate.edu\/agbio\/wp-content\/uploads\/sites\/127\/2022\/10\/Hemp-plant-infected-bctv.jpg” alt=”hemp plant infected with bctv” _builder_version=”4.21.0″ _module_preset=”default” body_line_height=”1.4em” image_icon_custom_margin=”||-22px||false|false” global_colors_info=”{}”]<\/p>\n Hemp plant infected with beet curly top virus. Note the curling of leaves. Image credit: Whitney Cranshaw, Colorado State University, Bugwood.org<\/em><\/p>\n [\/et_pb_blurb][et_pb_blurb image=”https:\/\/agsci.colostate.edu\/agbio\/wp-content\/uploads\/sites\/127\/2022\/10\/Hemp-plant-yellowing-stunted-growth.jpg” alt=”Hemp plant yellowing” _builder_version=”4.21.0″ _module_preset=”default” body_line_height=”1.4em” image_icon_custom_margin=”||-22px||false|false” global_colors_info=”{}”]<\/p>\n Hemp plant infected with BCTV. Note the yellowing and stunted growth of the plant, even in the absence of leaf disfiguration. [\/et_pb_blurb][et_pb_blurb image=”https:\/\/agsci.colostate.edu\/agbio\/wp-content\/uploads\/sites\/127\/2022\/10\/Jujube-tree-with-multiple-witches-brooms.jpg” alt=”Witches broom on jujube tree” _builder_version=”4.21.0″ _module_preset=”default” body_line_height=”1.4em” image_icon_custom_margin=”||-22px||false|false” global_colors_info=”{}”]<\/p>\n Jujube tree with multiple witches\u2019 brooms, caused by infection of a phytoplasma. Image credit: William M. Brown Jr., Bugwood.org<\/em><\/p>\n [\/et_pb_blurb][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.17.4″ _module_preset=”default” background_color=”#F1F1F1″ global_colors_info=”{}”][et_pb_row _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.16″ _module_preset=”default” global_colors_info=”{}”][et_pb_text admin_label=”Squiggle” _builder_version=”4.17.4″ _module_preset=”default” header_font=”||||||||” header_text_align=”left” header_font_size=”22px” custom_padding=”||||false|false” saved_tabs=”all” global_colors_info=”{}”]<\/p>\n\t\t [\/et_pb_text][et_pb_text _builder_version=”4.24.2″ _module_preset=”default” header_2_font_size=”36px” header_3_font_size=”26px” global_colors_info=”{}”]<\/p>\n Females of beet leafhopper begin laying eggs in the early spring, and each female can lay hundreds of eggs. There are typically multiple generations per year. Eggs are elongated, slightly curved, and white or yellow, and they are deposited singly inside leaves and stems.<\/p>\n Nymphs develop through five instars. The first instar is transparent white after emerging from the egg but within a few hours it becomes yellow or green, and later instars have black, brown, and red spots. The beet leafhopper acquires BCTV by feeding on infected weeds and can transmit the virus to nearby cultivated plants.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.17.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_row _builder_version=”4.17.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.17.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_text admin_label=”Squiggle” _builder_version=”4.17.4″ _module_preset=”default” header_font=”||||||||” header_text_align=”left” header_font_size=”22px” custom_padding=”||||false|false” saved_tabs=”all” locked=”off” global_colors_info=”{}”]<\/p>\n\t\t [\/et_pb_text][et_pb_text _builder_version=”4.24.2″ _module_preset=”default” header_3_font_size=”26px” global_colors_info=”{}”]<\/p>\n The transmission of BCTV through beet leafhopper feeding poses a significant threat to hemp cultivation, even though the feeding itself does not significantly injure the plant. Infected plants will display various symptoms depending on the plant\u2019s growth stage at the time of infection. Young plants are the most susceptible.<\/p>\n Leaves of young hemp infected with BCTV have light green color and yellowing of new growth is common. Older leaves of infected plants tend to display dark and light green mottling due to chlorosis. The mosaic mottling continues into mid growth of the plant and includes more severe yellowing. Infection at this stage will cause curling and twisting of new leaves. Leaves of the apical meristem will also be stunted with a shortened stem at the internode, producing a symptom known as \u201cwitch\u2019s broom\u201d.<\/p>\n The symptoms described above typically appear at or above the infection site and seem to occur on individual branches. Some branches show no symptoms and will cover and outgrow symptomatic branches. Symptoms of late-stage infection include severe curling and possibly twisting of leaves, stunting, and necrosis of yellow leaves. All these symptoms will significantly reduce yields, and dwarfed plants with severe infections tend to experience high mortality later in the season. It is unknown whether BCTV is seed transmitted.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.18.0″ _module_preset=”default” background_color=”#F1F1F1″ global_colors_info=”{}”][et_pb_row _builder_version=”4.17.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.17.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_text admin_label=”Squiggle” _builder_version=”4.17.4″ _module_preset=”default” header_font=”||||||||” header_text_align=”left” header_font_size=”22px” custom_padding=”||||false|false” saved_tabs=”all” locked=”off” global_colors_info=”{}”]<\/p>\n\t\t [\/et_pb_text][et_pb_text _builder_version=”4.24.2″ _module_preset=”default” header_3_font_size=”26px” global_colors_info=”{}”]<\/p>\n Treatment thresholds have not yet been established for beet leafhopper in hemp, but the pest should still be monitored to determine whether control measures are necessary. Note that other leafhopper species may be present in hemp fields, therefore accurate identification of beet leafhopper is crucial. To monitor beet leafhopper in hemp, yellow sticky cards can be placed on the field edges, inspected weekly, and replaced as needed. Sweep nets can also be used to conduct surveys in fields.<\/p>\n There are many natural enemies of beet leafhopper, including spiders, green lacewings, assassin bugs, bigeyed bugs, and certain species of parasitic flies and wasps. When possible, these natural enemies should be promoted in the field through appropriate means of conservation biological control.<\/p>\n Since young plants are the most susceptible to BCTV infection, deploying a physical barrier over seedlings can help protect against beet leafhoppers. Trap crops can also be planted on the edge of fields to concentrate the pest in these areas for targeted sprays. Sugar beet is the preferred food source of the beet leafhopper and makes for an ideal trap crop.<\/p>\n Scouting nearby crops and weeds for the presence of beet leafhopper is recommended. When beet leafhopper is present, these breeding areas should be treated with both soil and foliar applications. This will help knock down beet leafhopper populations before they begin migrating to nearby hemp fields.<\/p>\n Beet leafhopper is resistant to many commonly used pesticides in its preferred host \u2013 sugar beets \u2013 and utility of pesticides commonly used in hemp in Colorado is still under investigation.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section][et_pb_section fb_built=”1″ _builder_version=”4.18.0″ _module_preset=”default” background_color=”#FFFFFF” global_colors_info=”{}”][et_pb_row _builder_version=”4.17.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.17.4″ _module_preset=”default” global_colors_info=”{}”][et_pb_text admin_label=”Squiggle” _builder_version=”4.17.4″ _module_preset=”default” header_font=”||||||||” header_text_align=”left” header_font_size=”22px” custom_padding=”||||false|false” saved_tabs=”all” locked=”off” global_colors_info=”{}”]<\/p>\n\t\t [\/et_pb_text][et_pb_text _builder_version=”4.24.2″ _module_preset=”default” header_3_font_size=”26px” global_colors_info=”{}”]<\/p>\n California Department of Food and Agriculture. (n.d.).<\/strong> Beet Curly Top Virus Control Program. Available https:\/\/www.cdfa.ca.gov\/plant\/ipc\/curlytopvirus\/ctv_hp.htm<\/a><\/p>\n Colorado State University. (n.d.).<\/strong> Leafhoppers. Available https:\/\/webdoc.agsci.colostate.edu\/hempinsects\/PDFs\/Leafhoppers%20Revision%202020.pdf<\/a><\/p>\n Hu, J., and Masson, R. 2021.<\/strong> Beet Curly Top Virus in Industrial Hemp. The University of Arizona: Cooperative Extension. Available https:\/\/extension.arizona.edu\/sites\/extension.arizona.edu\/files\/pubs\/az1931-2021.pdf<\/a><\/p>\n Oregon State University. (n.d.).<\/strong> Hemp-Leafhoppers. Pacific Northwest Pest Management Handbooks. Available https:\/\/pnwhandbooks.org\/insect\/agronomic\/hemp\/hemp-leafhoppers<\/a><\/p>\n
\u2022 BCTV is much more prevalent in western Colorado than in eastern Colorado. In 2019, there was a damaging outbreak of BCTV in the state.
\u2022 Hemp appears to be highly susceptible to BCTV, which was first reported in hemp grown in western Colorado in 2015. Young plants are especially susceptible to this virus.<\/p>\n
Image credit: Whitney Cranshaw, Colorado State University, Bugwood.org<\/em><\/p>\nLife history and habits<\/h2>\n
Injury<\/h2>\n
Monitoring<\/h2>\n
Biological control<\/h2>\n
Cultural control<\/h2>\n
Chemical control<\/h2>\n
References<\/h2>\n