Laboratory Evaluation of Tween 20 for Potential Use in Control of Cacopsylla pyri L. Eggs and Nymphs (Homoptera: Psyllidae)
Abstract
The toxicity of the Tween 20, also known as polyoxyethylene (20) sorbitan monolaurate, was evaluated against the summerform pear psylla Cacopsylla pyri (L.) (Homoptera: Psyllidae) under laboratory conditions. Tween 20 was applied at 1, 2, 3, 7, 10, 20 and 30 ml/l concentrations onto eggs and nymphs of C. pyri on pear shoots. Water was used as a control treatment. The toxic effect on eggs and nymphs was determined by counting treated eggs and nymphs, live or dead. Despite low toxicity to psyllid eggs, Tween 20 showed significant toxic effects against nymphs. The mortality rates of eggs were 3.2%, 2.1%, 1.0%, 12.8%, 13.5%, 100.0%, 100.0% at 1, 2, 3, 7, 10, 20 and 30 ml/l concentrations, respectively. The highest toxic activity was recorded at concentrations of 20 and 30 ml/l. The mortality rates of nymphs were 7.2%, 21.0%, 49.9%, 96.5%, 100.0%, 96.5%, and 100.0% at above concentrations in the same order, respectively. Tween 20 at 3, 7, 10, 20 and 30 ml/l concentrations showed the highest toxic activity to psyllid nymphs, while concentrations of 1 and 2 ml/l had the lowest toxicity compared to water control. No significant phytotoxic effect was observed at all concentrations except for concentrations at 20 and 30 ml/l. In conclusion, Tween 20, either alone or in combination with pesticides, may provide an effective alternative to control pear psylla nymphs.
Keywords
Tween 20, Cacopsylla pyri, Toxicity, Detergents, Soaps, Surfactants, Pear
References
- Blomquist CL, and Kirkpatrick BC (2002). Frequency and seasonal distribution of pear psylla infected with the pear decline phytoplasma in California pear orchards. Phytopathology, 92: 1218-1226.
- Butler GD, Puri SN, and Henneberry TJ (1991). Plant-derived oil and detergent solutions as control agents for Bemisia-tabaci and Aphis-gossypii on cotton. Southwestern Entomologist, 16(4): 331-337.
- Curkovic T, Araya JE (2004). Acaricidal action of two detergents against Panonychus ulmi (Koch) and Panonychus citri (Mcgregor) (Acarina: Tetranychidae) in the laboratory. Crop Protection, 23: 731-733.
- Curkovic T, Araya J, Canales C, and Medina A (2006). Evaluation of two agriculture detergents as control alternatives for Green Peach Aphid and Two spotted Spidermite, Two Pests Affecting Peach Orchards in Chile. Proc. 6th Intl. Peach Symposium Ed. R. Infante Acta Hort. 713.
- Erler F (2004). Natural enemies of the pear psylla Cacopsylla pyri in treated vs untreated pear orchards in Antalya, Turkey. Phytoparasitica, 32: 295-304.
- Erler F, and Cetin H (2007). Effect of kaolin particle film treatment on winterform oviposition of the Pear Psylla Cacopsylla pyri. Phytoparasitica, 35(5): 466-473.
- FAO (2013a). Pear production of commodity in Turkey, http://faostat3.fao.org/browse/Q/QC/E, (04.2016).
- FAO (2013b). Pear exports of Turkey, (http://faostat3.fao.org/browse/T/TP/E), (04.2016).
- Garcia-Chapa M, Sabate J, Lavina A, and Batlle A (2005). Role of Cacopsylla pyri in the epidemiology of pear decline in Spain. Eur. J. Plant Pathol., 111: 9-17.
- Gencer NS and Kovanci B 2000. Bursa ilinde armutlarda zararlı Cacopsylla pyri (L.) (Homoptera:Psyllidae)’nin biyolojisi. Türkiye IV. Entomoloji Kongresi (12-15 Eylül 2000, Aydın) Bildirileri, s 101-110.