BIORATIONAL CONTROL METHODS FOR INSECT PESTS OF POTATO
Location: Fruit and Vegetable Insect Research
Title: Entomopathogenic fungi (Hypocreales) for control of potato psyllid, Bactericerta cockerelli (Sulc)(Hemiptera: Triozidae) in an area endemic for zebra chip disease of potato
Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 16, 2010
Publication Date: January 19, 2011
Citation: Lacey, L.A., Liu, T.X., Buchman, J., Munyaneza, J.E., Goolsby, J., Horton, D.R. 2011. Entomopathogenic fungi (Hypocreales) for control of potato psyllid, Bactericerta cockerelli (Sulc)(Hemiptera: Triozidae) in an area endemic for zebra chip disease of potato. Biological Control. 56:271-278.
Interpretive Summary: The potato psyllid is a serious pest of potato and related vegetables. It has recently been shown to transmit a bacterium that results in a disease of potato known as zebra chip. This disease is responsible for millions of dollars in losses to the potato industry in the southwestern United States and Mexico. The conventional means of control of potato psyllid is with broad spectrum chemical pesticides that are also lethal to beneficial insects and have potential risks for the environment and people. In an effort to develop alternative methods of control that are safe for the environment and the food supply, scientists at USDA-ARS Wapato, WA and Weslaco, TX, and Texas A & M University evaluated two commercially produced insecticidal fungi for control of potato psyllid in the potato growing area near Weslaco, TX. They demonstrated good insecticidal activity of both products. Our results indicate that both fungi might be useful as environmentally friendly components of an integrated strategy for control of potato psyllid.
Potato psyllid, Bactericera cockerelli (Šulc), is a serious pest of potato, tomato and other solanaceous vegetables in the United States, Mexico, Central America, and New Zealand and is responsible for transmission of Candidatus Liberibacter solanacearum causing a disease known as “zebra chip” (ZC). Entomopathogenic fungi could provide an environmentally friendly component of a softer integrated pest management (IPM) strategy for control of B. cockerelli and other potato pest insects. Field trials of commercial formulations of Metarhizium anisopliae (F 52®, Novozymes Biologicals) and Isaria fumosorosea (Pfr 97®, Certis USA) and Agri-Mek®, (abamectin, Syngenta USA) were conducted in Weslaco, Texas in 12009 and 2010. In 2009 F 52 applied at 0.51, 1.1, and 2.2 l/ha and Agri-Mek applied at 0.584 ml/ha produced season long reductions of B. cockerelli eggs and nymphs of 45, 59, 67, and 63% respectively. Mean tuber yield per plant for controls, the 3 rates of F52 and Agri-Mek were 475, 441, 448, 452, and 576 g, respectively. Only Agri-Mek produced significant reductions in plant damage and ZC symptoms. The first trial in 2010 compared Pfr 97 at 1.1 kg/ha with and without 1% Trilogy® (neem oil, Certis, USA), and Agri-Mek at 584 ml/ha resulting in psyllid reductions of 78, 76, and 84%, respectively. Tuber yields in control plots and those treated with Pfr, Pfr plus Trilogy and Agri-Mek were 775, 893, 952 and 943 g/plant, respectively. Significantly greater tuber yield and decreased plant damage and ZC symptoms were observed for all treatments. In the second 2010 trial, F 52 was applied at 1.1, and 2.2 l/ha and Pfr 97 at 1.1 and 2.2 kg/ha producing 62, 62, 66, and 65% reduction, respectively. Mean yield of tubers for controls and the 4 fungus treatments were 621, 709, 859, 927, and 787 g/plant, respectively. Significantly increased tuber yield was observed for all fungal treatments except the low F 52 application rate. All fungal treatments significantly reduced plant damage and ZC symptoms.