Evaluation of the daily periodicity of acaricides and inhibition of hatching by spiracle-blocking insecticides for control of two-spotted spider mite (green form)

• Published in: Annual Report of The Kansai Plant Protection Society Vol. 61; pp. 61 - 68
• Main Authors: Horikawa, Hidenori, Ito, Ryotaro, Koide, Tetsuya, Ohashi, Hiroko, Takeyama, Keiko, Kato, Kenji, (Kojima), Hiroko Ando
• Format: Journal Article
• Language: Japanese; English
• Published: The Kansai Plant Protection Society 31.05.2019
• Subjects: daily periodicity; inhibition of hatching; spiracle-blocking; Tetranychus urticae (green form); two-spotted spider mite (green form)
• ISSN: 0387-1002; 1883-6291
• DOI: 10.4165/kapps.61.61

The susceptibilities of female Tetranychus urticae (green form) collected in a strawberry field in Nagakute City, Aichi prefecture, Japan, against acaricides were examined at 2 and 10 hours after the onset of the light period, and in the dark period.The mortality rates with emamectin benzoate emulsion, milbemectin emulsion, acequinosyl flowable, and reduced starch glycated solution applied at 2 hours after the onset of the light period tended to be lower than those in the other two treatment groups. Regarding cyenopyrafen flowable and cyflumetofen flowable, mortality after treating at 2 hours after the onset of the light period was higher than in the other two treatments. For the bifenazate flowable and sulfur, mortality did not differ among the treatment times. Furthermore, there was no apparent difference in mortality between treatment at 10 hours after the onset of the light period and that in constant dark conditions, with any acaricide.Ovicidal effects of a variety of spiracles-blocking acaricides were examined against T. urticae collected in a strawberry field in Gamagori City, Aichi prefecture. Treatment of either highly refined machine oil emulsion or machine oil emulsion resulted in a substantial reduction in hatching rates, mainly due to the blocking of spiracles. Hatching inhibition effects were also observed with the rapeseed oil emulsion, fatty acid glyceride emulsion, and blended oil emulsion, but with the propylene glycol mono fatty acid ester emulsion, hydroxypropyl starch solution, and etoxazole flowable, hatching was almost never inhibited. The susceptibility of this population of T. urticae to etoxazole flowable was suspected to have decreased.