Kentucky State University
The Effectiveness of Ripe Pawpaw Fruit Extract for Managing Striped Cucumber Beetle on Squash
Institution
Kentucky State University
Faculty Advisor/ Mentor
John Sedlacek; Karen Friley; Kirk Pomper; Jeremiah Lowe
Abstract
Fruit tissues of pawpaw (Asimina triloba) were recently found to contain annonaceous acetogenin compounds having insecticidal activity. Laboratory experiments were performed to determine the effects of pawpaw fruit extract on mortality and feeding deterrence of striped cucumber beetle (Acalymma vittatum). Ripe pawpaw fruit pulp was extracted with 100% ETOH to obtain acetogenin compounds. Pulp extracts of 0, 10, 100, 1,000, 10,000 and 50,000 ppm were used to assess feeding deterrence and mortality of beetles. Buttercup squash leaf disks 3.5 cm in diameter were treated individually with each concentration and placed on water moistened filter paper in 9 cm plastic Petri dishes. Five striped cucumber beetles were placed on each leaf disk. All Petri dishes were then placed in an environmental growth chamber set at 27° C and a 16: 8 hr light: dark photo period. After 24 hr the cucumber beetles were removed. An LC50 of 50,538 ppm was calculated for the extract concentration required to kill 50% of the beetles. Pawpaw fruit extract reduced feeding by 90% and 98% in the 10,000 and 50,000 ppm treatments, respectively. At 10,000 ppm 10% of the beetles were killed, however only 10% of the leaf tissue was consumed. A LFC10 value of 2,033 ppm was calculated for the extract concentration required to limit feeding to 10% of the leaf. This suggests that pawpaw fruit extracts may be effective insect feeding deterrents. The duration of treatment effectiveness and susceptibility of other pest and beneficial insect species to the extracts should be examined.
The Effectiveness of Ripe Pawpaw Fruit Extract for Managing Striped Cucumber Beetle on Squash
Fruit tissues of pawpaw (Asimina triloba) were recently found to contain annonaceous acetogenin compounds having insecticidal activity. Laboratory experiments were performed to determine the effects of pawpaw fruit extract on mortality and feeding deterrence of striped cucumber beetle (Acalymma vittatum). Ripe pawpaw fruit pulp was extracted with 100% ETOH to obtain acetogenin compounds. Pulp extracts of 0, 10, 100, 1,000, 10,000 and 50,000 ppm were used to assess feeding deterrence and mortality of beetles. Buttercup squash leaf disks 3.5 cm in diameter were treated individually with each concentration and placed on water moistened filter paper in 9 cm plastic Petri dishes. Five striped cucumber beetles were placed on each leaf disk. All Petri dishes were then placed in an environmental growth chamber set at 27° C and a 16: 8 hr light: dark photo period. After 24 hr the cucumber beetles were removed. An LC50 of 50,538 ppm was calculated for the extract concentration required to kill 50% of the beetles. Pawpaw fruit extract reduced feeding by 90% and 98% in the 10,000 and 50,000 ppm treatments, respectively. At 10,000 ppm 10% of the beetles were killed, however only 10% of the leaf tissue was consumed. A LFC10 value of 2,033 ppm was calculated for the extract concentration required to limit feeding to 10% of the leaf. This suggests that pawpaw fruit extracts may be effective insect feeding deterrents. The duration of treatment effectiveness and susceptibility of other pest and beneficial insect species to the extracts should be examined.