神澤葉蟎為害桑葉對家蠶繭產量影響之評估

EFFECT OF THE INFESTATION OF TETRANYCHUS KANZAWAI KISHIDA (ACARINA: TETRANYCHIDAE) ON THE SILK PRODUCTION OF THE SILKWORM, BOMBYX MORI (L.) (LEPIDOPTERA: BOMBYCIDAE)

何琦琛(Chyi-Chen Ho) ； 黃勝泉(Sheng-Chyuang Hwang) ； 王世華(Shyh-Hwa Wang)

《中華昆蟲》 9卷2期 (1989/09) Pp. ap7+203-209

https://doi.org/10.6660/TESFE.1989019

摘要

本試驗於1986年8月至11月進行，當蠶種出庫前，在桑園中接種神澤葉蟎，造成A、B、C、D等4種不同之密度。自第3齡蠶起，飼以此桑葉。此時各處理第6－10葉片上每葉片之平均葉蟎密度分別為8.8、29.2、88.8、103.9隻，對照區為2.2隻。飼育家蠶之上繭數及食桑量在各處理間差異不顯著。C及D區之熟蠶重及繭重（含蛹）均顯著減少，而繭淨重及繭層率僅D處理顯著降低。亦卽僅D區蠶隻之吐絲能力受到顯著影響。被害桑葉之重量明顯減輕，蠶隻為維持一定之食桑量，增加取食桑葉片數。因而單位面積桑園可飼養之蠶隻數減少，從而降低單位面積桑園之產絲量。計算在桑園中神澤葉蟎之累積為害度（蟎日），對相對桑葉重及相對蠶絲產量之相關性較蟎密度更高。當蠶隻進入第3齡，而神澤葉蟎之累積為害度已達約190及539蟎日時，蠶絲產量將分別約減少15%及35%。

並列摘要

During the fall of 1986, Tetranychus kanzawai was inoculated to mulberry right before the raising of silkworm to induce four different spider mite densities. Silk worms were fed with these mulberry leaves since the third instar. The mite densities, adults plus nymphs per leaf, were 8.8, 29.2, 88.8, and 103.9 for A,B,C, and D treatments respectively, and 2.2 for check at the begining of the third stadium of silkworm. The number of first grade cocoon produced and the total food consumption were not significantly different among treatments at 0.05 level. The mature laval weight and cocoon weight (including pupa) of C and D treatments decreased significantly. The net weight of cocoon and the silk producing rate of D treatment reduced significantly. That is only the silk-production capability of the silkworm raised in D treatment were significantly influenced. The weight of mulberry leaf was lowered significantly by the spider mite infestation. Consequently, silkworms fed more leaves to achieve a certain food consumption. Therefore, a smaller number of silkworm would be raised from an unit acrage of mulberry field and resulted in lower silk production. The relative leaf weight and the relative silk production had a higher correlation with the accumulative infestation (mite-day) than with the mite density. The silk production would be reduced, approximately, 15 and 35%, if the accumulative infestation of the kanzawa spider mite reached 190 and 539 mite-day, respectively, when the silkworm moult into the third instar.