Archives of Phytopathology and Plant Protection (2007) 40, 441-450

Ayhan Gökçe, Mark E. Whalon, Halit Çam, Yusuf Yanar, Ibrahim Demirtas and Nezhun Gören (2007)
Contact and residual toxicities of 30 plant extracts to Colorado potato beetle larvae
Archives of Phytopathology and Plant Protection 40 (6), 441-450
Abstract: Contact and residual toxicities of 30 plant extracts were investigated on third instar larvae of Colorado potato beetle, Leptinotarsa decemlineata. The plant samples were collected during the spring and summer of 2002 and were dried and ground. The plant samples were treated with methanol and the residue was eluted with distilled water containing 10% acetone, resulting in plant extracts. In contact bioassays, the beetle larvae were treated with 40% (w/w) plant extract using a Potter Spray Tower. The insects were incubated at 28±2°C under a 16 h: 8 h photo regime and the mortality was recorded at 24 h intervals for 7 days. The plant extracts exhibited varying toxicity to the larvae ranging from 0 - 91% after 24 h incubation and Artemisia vulgaris, Hedera helix, Humulus lupulus, Lolium temulentum, Rubia tinctoria, Salvia officinalis, Sambucus nigra, Urtica dioica, Verbascum songaricum, and Xanthium strumarium extracts resulted in significantly higher mortality than the control. Generally, prolonged incubation time did not result in an increase in mortality. After 48 h of incubation, 10 plant extracts yielded a significant mortality and H. lupulus extract, the most toxic extract among those tested, caused 99% mortality which is similar the mortality caused by the chemical standard, imidacloprid. In residual assays, potato leaflets were treated with 20% (w/w) plant-extract concentrations using a Potter Spray Tower. Third instar larvae were added to a glass jar to which treated leaflets were transferred before incubation at the temperature and photo regime described above. Mortality was recorded at 24 h intervals for 7 days. Five plant extracts, H. lupulus, L. temulentum, Reseda lutea and Solanum nigrum, induced significantly higher mortalities compared with controls. Chenopodium album extract was the most toxic, killing 34.9% of exposed larvae, followed by L. temulentum, H. lupulus and S. nigrum after 72 h incubation. The results exhibited that certain plant extracts were toxic to the beetle larvae and may have potential for controlling this destructive pest under field conditions.
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Link to article at publishers website
Database assignments for author(s): Ayhan Gökçe, Mark E. Whalon

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Leptinotarsa decemlineata