Study on activity of some indagenous plants of Southern Thailand on the mortality of diamondback moth
การศึกษาฤทธิ์ของพืชบางชนิดในท้องถิ่นภาคใต้ประเทศไทยต่อการตายของหนอนใยผัก
Sunthron Pipithsangchan, D. of Pest Management, F. of Natural Resources, PSU.
Tiwa Butpha, D. of Pest Management, F. of Natural Resources, PSU.
Parichart Palintorn, D. of Pest Management, F. of Natural Resources, PSU.
Supreeya Yuenyongsawad, D. of Pharmacognosy and Pharmaceutical Botany,
F. of Pharmaceutical Sci., PSU.
Sanan Subhadhirasakul, Assoc. Prof., D. of Pharmacognosy and Pharmaceutical Botany, F. of Pharmaceutical Sci., PSU.
Corresponding e-mail : ssanan@ratree.psu.ac.th
Published : Songklanakarin J Sci Technol 2000, 22(4) : 447-455
Key words : diamondback moth, Plutella xylostella, Azadirachta excelsa, Toddalia asiatica, Ericybe coriacea, Crypteronia paniculata, Coleus parvifolius
Methanolic extract from Azadirachta excelsa Jack. (leaves), Toddalia asiatica Lamk. (stems),
Ericybe coriacea Wall. (stems), Crypteronia paniculata Blume (leaves) and Coleus parvifolius Benth. (Leaves) were laboratory tested for their mortal activity on the third instar larvae of diamondback
moth (Plutella xylostella Linn.) by topical application and spraying methods. The LC50 at 72 hours
after test of the methanolic extracts from A. excelsa, T. asiatica, E. coriacea, C. paniculata and C. parvifolius using topical application were 847.6 mg/l, 935.2 mg/l, 4068.2 mg/l, 3176.9 mg/l and
1375.6 mg/l, respectively, and using by spraying were 469.7 mg/l, 806.7 mg/l, 2429.4 mg/l, 1900.6
mg/l and 1024.5 mg/l, respectively. The methanolic crude extract from A. excelsa showed the most effective mortality on diamondback moth, while E. coriacea showed the lowest effective property.
The surviving larvae showed unusual development of the pupal stage eg. darker colour, non-func-tioned silk thread, failure of adult emergence and eventually death.
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