Plant Extracts For Biological Activity And Mechanism Of Vegetable Armyworm

In this study, the bioactivies of twenty ethanol extracts of corresponding organaand parts of plants against 2 species of vegetable pests, and the co-toxicities of the plantextracts mixed with them, and CTC, and the effection of weakening for Spodopteraexigua from two plant extracts, and the bioactivies of AchE and CarE on S. exigua werestudied by different methods, the results indicated that:Among the 20 extracts, the corrected mortality of 6 plant extracts were more than90% and the antifeeding rate of 2 plant extracts were more than 90% and 3 plantextracts had significant growth inhibition (＞80%) to Spodoptera exigua. The correctedmortality of 8 plant extracts were more than 90% and the antifeeding rate andsignificant growth inhibition of 20 plant extracts were all lower to Spotoptera litura.The results of combinatorial (v/v) test of the plant extracts showed that: toSpodoptera exigua, the toxic action of the combination of Araliaceae and Euphorbiaceaeextractions (1: 9) was 83.33%, and the co-toxity exponent was 269.8283; toSpotoptera litura, the toxic action of the combination of Araliaceaeand Euphorbiaceaeextracts (9: 1) was 86.67%, and the co-toxity exponent was 243.6776.The result of effection of weakening of two plant extracts—Araliaceae andEuphorbiaceae on Spodoptera exigua is that: we evaluate the effects of plant extractionsfor Spodoptera exigua on upgrowth and propagate. Euphorbiaceae andAraliaceaeextractions have better toxic action of Spodoptera exigua (2L), alsoEuphorbiaceae extractions have better antifeeding action and crowth inhibition action.Two plant extractions can prolong development period of larva, but cannot prolongpupae period; also, they have some effects on pupation ratio, eclosion ratio, sex ratio,oviposition.The result of the bioactivies of AchE and CarE on Spodoptera exigua is that: twoplant extracts all have restrain on AchE. And, the plant extract of Araliaceae (1g/ml) could restrain the bioactivies of AchE, but lower consistence have no bioactivies. Theplant extract ofEuphorbiaceae have better bioactivies on AchE. two plant extracts ofAraliaceae and Euphorbiaceae all have better bioactivies on CarE.