長毛細蟎之生殖、發育及傳播

Abstract

水稻稻桿段做為室內長毛細蟎飼養之材料，比葉鞘更容易獲得大量之細蟎，並能延緩村料之老化。長毛細蟎具有產雄生殖(arrhentoky)形式之孤雌生殖。溫度之高低，對長毛細蟎之發育及生殖有不同之影響；細蟎之卵到成蝓的發育全期，產卵前期，成蝸之壽命，常隨溫度之降低而延長。於32、28、25、20、16℃溫度下，發育全期分別為4、5、6、7、28、6天，產卵前期分別為2、2.5、5.6、8.5、21天。產卵期分別為8、7.5、9.2、10、4、22.0天，雌蟎之壽命一般較雄蟎為長，其壽命分別為10.8、10.8、15、20、40.5天，雄蟎之壽命分別為4、4、10、17、35天。在各種溫度下，細蟎之發育全期內幼蟎都比卵期或靜止期為短。雌蟎之產卵數，則以高溫為多，在32、28、25、20、16℃分別為70.6、56.5、61.5、40及23.3個。一對細蟎之後代，其雌雄比率，亦以高溫為高，在32、28、25、20、16℃分別為22/1、3.2/l、2.4/1、1.8/l、0.75/1。雨水能將病株之葉鞘內的長毛細蟎沖洗出來，有助於長毛細蟎之傳播。 The rice stem segments utilized to be a material instead of leaf sheath segments for the reproduction of rice tarsonemid mite, Steneotarsonemus spinki Smiley, were easier to get a large amount of the mites in the laboatory. Arrhenotoky, one type of the parthenogenesis, was found in the reproduction of the rice tarsonemid mite besides the bisexual reproduction. The development and reproduction of the mite were greatly influenced by the ambient temperature. The lower the temperature from 16 to 32℃, the longer the period of development from egg to adult, or preoviposition and oviposition stage, longevity of adult. At 32, 28, 25, 20 and 16℃, the mite required 4, 5, 6, 7 and 28.6 days to complete its development from egg to adult, respectively; the preoviposition period 2, 2.5, 5.6, 8.5 and 21 days, the oviposition period 8, 7.5, 9, 10 and 22 days, respectively. The longevity of adult female was 10.8, 10.8, 15, 20 and 40.5 days, and the male 4, 4, 10, 17 and 35 days, respectively, at 32, 28, 25, 20 and 16℃. In the developmental period, the time of larval stage was shorter than that of egg stage or quiescent stage at 32-16℃. The average number of the eggs laid by each female was 70.6, 56.5, 61.5, 40 and 23 respectively, at 32, 28, 25, 20 and 16℃. The sex ratio (female : male) of the first generation of the bisexual reproduction, at 32, 28, 25, 20 and 16℃, was 22 :1, 3.2 :1, 2.4 :1, 1.8 1, and 0.75 :1, respectively. The mites could be washed out of from diseased plants and transmitted by rain fall.