Mass production of Tetranychus urticae Koch and its applications
Date Issued
2006
Date
2006
Author(s)
Lee, Chi-Yang
DOI
en-US
Abstract
In this study, we developed a system for the mass production of the two-spotted spider mite, Tetranychus urticae Koch in the laboratory and in a greenhouse. First, T. urticae was reared on soybeans (Chin-pe Tao, a native soybean variety) hydroponically without nutrients in the laboratory at 26 ± 1℃ and 65％-95％ RH, under a 14: 10-h (L: D) photoperiod. The greatest numbers of spider mites per bean seedling were 909-962 on days 10-11. The greatest numbers of spider mites per rearing unit (30 x 60 cm) were 538,000-543,000 for feeding on ca. 600 bean seedlings on days 10-11. The frequencies of T. urticae eggs and larvae on bean seedlings were over 70%. It is recommended that the optimal harvesting time for rearing T. urticae is on days 10-11. Second, T. urticae was reared on soybeans hydroponically without nutrients in a greenhouse and were extracted from bean seedlings using a vibratory sieve shaker. In experiment I, the greatest number of spider mites per rearing unit (30 x 60 cm) was 851,000 on day 8 and showed an 8.51-fold increase to the initially inoculated 100,000 individuals. In experiment II, the greatest number of spider mites per rearing unit was 744,000 on day 9 and showed a 12.4-fold increase to the initially inoculated 60,000 individuals. The greatest yield of T. urticae eggs and larvae per rearing unit appeared on day 8 in both experiments I (672,290 individuals) and II (561,600 individuals). It is recommended that the optimal harvesting time for the mass production of T. urticae is on day 8. All life stages of the residual population of T. urticae on bean seedlings after extraction can be used to re-infest new host plants. They recover very well. The yield and extraction rate of spider mites can be predicted. The population densities of T. urticae were significantly correlated with the rearing period for the linear regression. Regression analyses showed a significant logarithmic relationship between the extraction rate of T. urticae and the vibration time. An extraction-reproduction cycle was established. The operating time is very short, and most importantly, the spider mites are alive. Third, Phytoseiulus persimilis was reared in arenas set up established in the laboratory at 26 ± 1℃ and 65％-95％ RH, under a 14: 10-h (L: D) photoperiod. The population of P. persimilis feeding on a 160-fold greater number of T. urticae showed the greatest increase on day 13, an average of 22.9-fold. The ratio of T. urticae to P. persimilis was 5.5. After day 15, the population increase of P. persimilis feeding on a 160-fold greater number of T. urticae was lower than 7.7-fold per arena. It is recommended that the optimal harvesting time for rearing of P. persimilis is on days 13-14. Finally, this study also assessed on the control effect of soap solution on T. urticae. Five kinds of soap solutions (4 g (AI)/l) made by different household soap were evaluated by contact and residual bioassays on the adult and egg stages of T. urticae in the laboratory. The mortalities of female adults immersed in each soap solution for 1 to 8 s exhibited no significant difference, and treated by soap (4 g (AI)/l) in distilled water, or by abamectin (0.01 g (AI)/l), the mortalities also exhibited no significant difference. The mortalities of female adults ranged from 93.1% to 98.6% among five soap solutions and that of abamectin solution was 100%. Soap solutions did not significantly affect T. urticae egg hatchability, and sequential second dipping could not completely eradicate the remaining nymphs. The mortality of nymphs ranged from 89.2% to 98.8% among those soap solutions. Soap residual bioassay showed that residues did not significantly affect the mortality of female adults as well. Divalent metal ion concentrations in soap solution could affect the soap activity on T. urticae. The mortality of female adults using each kind of soap dissolved in standard hard water was significantly lower than that same soap dissolved in distilled water.
Subjects
智利捕植蟎
二點葉蟎
大豆
青皮豆
萃取
大量繁殖
家用肥皂
皂液
生物檢定
標準硬水
Glycine max
Phytoseiulus persimilis
Tetranychus urticae
bioassay
extraction
mass production
rearing
soap solution
soybean
standard hard water
Type
thesis
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