大腸菌對於蓖麻蠶的影響

作者:黃雪香、嚴奉琰、繆端生

摘要：

作者等一直主張用生物防治害虫，尤其是細菌和濾過性毒可廣泛實施。1955-1959年間，謬端生與何仁傑曾以大腸菌處理蓖麻蠶發現蓖麻蠶皆發病而死，其 發病部位為消化器官及血液，大腸菌寄生於人體，對人體無害，如用來撲滅害虫實甚理想，一般農藥望塵莫及，其後美國加州大學寄來在美培養的大腸菌，作者等一 再重複實驗，發見該大腸菌並無誘發蓖麻蠶發病之毒力作用及現象。
試驗過程中，每一供試幼虫經口腔注入或體壁注射 1,900,000-3,600,000個大腸菌後，仍能照常取食，並繼續其正常發育。從切片中觀察，用大腸菌處理過的幼虫，其腸壁組織並無病變，其腸細胞仍屬完整，血球數量亦無顯著變化。
作者認為美國人腸中之大腸菌與中國人腸中之大腸菌，其環境及種系(Strain)不同，乃對蓖麻蠶引起不同之影響，故在應用上需注意其種系。

《詳全文》

Effect of Escherichia Coli on Erisilkworm. Philosamia Cynthia Ricini

Author: S. S. Huang, Y. F. Yen, T. S. Miu

Abstract：

From the review of the literature, it is apparent the Escherichia coli, is an important organism among the tribe Eschericheae, to cause the disease of insect. It was substantially demonstrated in the earlier reports that E. coli was the pathogen for silkworm, as well as for wax moth. However, as the result indicated in the pre-sent investigation, Eri-silkworm, Philosamia cynthia ricini Boisdu-val is non-susceptible to E. coli so far studied.
After oral ingestion and body cavity injection of bacterial sus-pension, the larvae fed normally and continued their development. The concentration used was approximately 1,200,000 to 3,000,000 bacterial cells per larva.
As observed from the histological study of alimentary tract there was no pathological change. The number of blood cells had no great change between treated and untreated larvae as well.
E. coli is not a pathogen for Eri-silkworm, why? It may be concerned with three factors: Host, pathogen, and environment. If this is the problem that remains for further study.