B. cockerelli adults are small, measuring about 2.5-2.75 mm long. The adults generally resemble tiny cicadas, largely because they hold their wings angled and roof-like over their body. B. cockerelli adults possess two pairs of clear wings;the front wings bear conspicuous veins and are considerably larger than the hind wings. The antennae are moderately long, extending almost half the length of the body. The overall body colour ranges from pale green at emergence to dark green or brown within 2-3 days, and eventually becomes grey or black thereafter. Prominent white or yellow lines are found on the head and thorax, and dorsal whitish bands are located on the first and terminal abdominal segments. These white markings are spot characteristics of the psyllid, particularly the broad, transverse white band on the first abdominal segment and the inverted ‘V’-shaped white mark on the last abdominal segment (Pletsch, 1947;Wallis, 1955), along with the raised white line around the circumference of the head. Adults are active in contrast to the largely sedentary nymphal stages. These insects are good fliers and readily jump when disturbed.
Related invasive species
- Bactericera cockerelli
Related Farm Practice
- Feeding
- Hosts
B. cockerelli is one of the most destructive potato pests in the western hemisphere. It was recognized in the early 1900s that B. cockerelli had the potential to be an invasive and harmful insect, particularly in western United States and Mexico (Šulc, 1909;Crawford, 1914;Compere, 1915;1916;Essig, 1917). By the 1920s and 1930s, B. cockerelli had become a serious and destructive pest of potatoes in most of the southwestern United States, giving rise to the description of a new disease that became known as ‘psyllid yellows’ (Richards, 1928;1931;1933;Binkley, 1929;Richards and Blood, 1933;List and Daniels, 1934;Pletsch, 1947;Wallis, 1955).
B. cockerelli has historically been associated with ‘psyllid yellows’ disease of potato and tomato (Richards and Blood, 1933). Psyllid yellows disease is thought to be associated with feeding by psyllid nymphs (List, 1925) and may be caused by a toxin associated with the insect (Carter, 1939), although the actual etiology of the disease is yet to be determined (Sengoda et al., 2010). More recently, this psyllid has been found to be associated with the bacterium ‘ Candidatus Liberibacter’ (Hansen et al., 2008;Liefting et al., 2009;Crosslin et al., 2010;Munyaneza, 2010;Munyaneza, 2012;Munyaneza and Henne, 2012) (see ISC datasheet on ‘ Candidatus Liberibacter solanacearum’ for details).
The characteristic above-ground plant symptoms of infestation by B. cockerelli in potatoes and tomatoes include retarded growth, erectness of new foliage, chlorosis and purpling of new foliage with basal cupping of leaves, upward rolling of leaves throughout the plant, shortened and thickened terminal internodes resulting in rosetting, enlarged nodes, axillary branches or aerial potato tubers, disruption of fruit set and production of numerous, small, and poor quality fruits (List, 1939;Pletsch, 1947;Daniels, 1954;Wallis, 1955;Munyaneza, 2012;Munyaneza and Henne, 2012).
The below-ground symptoms on potato include the setting of an excessive number of tiny misshapen potato tubers, production of chain tubers and early breaking of dormancy of tubers (List, 1939;Pletsch, 1947;Wallis, 1955). Additional potato tuber symptoms include collapsed stolons, browning of vascular tissue concomitant with necrotic flecking of internal tissues and streaking of the medullary ray tissues, all of which can affect the entire tuber. Upon frying, these symptoms become more pronounced and chips or fries processed from affected tubers show very dark blotches, stripes, or streaks, rendering them commercially unacceptable (Munyaneza et al., 2007a,b;2008;Secor et al., 2009;Crosslin et al., 2010;Miles et al., 2010;Munyaneza, 2012;Munyaneza and Henne, 2012);see the ISC datasheet on ' Candidatus Liberibacter solanacearum' for details.
B. cockerelli is found primarily on plants within the family Solanaceae. The psyllid attacks, reproduces and develops on a variety of cultivated and weedy plant species (Essig, 1917;Knowlton and Thomas, 1934;Pletsch, 1947;Jensen, 1954;Wallis, 1955), including crop plants such as potato (Solanum tuberosum), tomato (Solanum lycopersicon), pepper (Capsicum annuum), eggplant (Solanum melongena) and tobacco (Nicotiana tabacum) as well as non-crop species such as nightshade (Solanum spp.), groundcherry (Physalis spp.) and matrimony vine (Lycium spp.).
Adults have been collected from plants in numerous families, including Pinaceae, Salicaceae, Polygonaceae, Chenopodiaceae, Brassicaceae, Asteraceae, Fabaceae, Malvaceae, Amaranthaceae, Lamiaceae, Poaceae, Menthaceae and Convolvulaceae, but this is not the complete host range of this psyllid (Pletch, 1947;Wallis, 1955;Cranshaw, 1993). Beside solanaceous species, B. cockerelli has been shown to reproduce and develop on some Convolvulaceae species, including field bindweed (Convolvulus arvensis) and sweet potato (Ipomoea batatas) (Knowlton and Thomas, 1934;List, 1939;Wallis, 1955;Puketapu and Roskruge, 2011;Munyaneza, unpublished data).