Scott I M, Jensen H, Scott J G, Isman M B, Arnason J T, Philogène B J R
Biology Department, University of Ottawa, Ottawa, Ontario, Canada.
Arch Insect Biochem Physiol. 2003 Dec;54(4):212-25. doi: 10.1002/arch.10118.
The efficacy of extracts from two Piperaceae species, Piper nigrum L. and P. tuberculatum Jacq. were evaluated using larvae and adults of the Colorado Potato Beetle Leptinotarsa decemlineata (Say). Young larvae and neonates were the most susceptible; a 24-h LD(50) of 0.064% extract of P. tuberculatum was determined for 4-day-old larvae, while 0.05% extract of P. nigrum reduced larval survival up to 70% within one week after treatment of potato Solanum tuberosum L. (Solanaceae) plants. When an insecticide resistant strain of L. decemlineata larvae was tested with the P. tuberculatum extract, there was less than a 2-fold tolerance ratio compared to the 22-fold tolerance ratio to cypermethrin, a pyrethroid. Older larvae, pre-pupal stage and adults, were less sensitive to the P. nigrum extracts; the 24-h LD(50) was 0.5% (95% C.I. = 0.36, 0.65). However, the same concentration was equally effective under field conditions. In the greenhouse, P. nigrum at 0.5% was as effective at reducing adult L. decemlineata feeding as combinations with 2 separate botanical mixtures, garlic and lemon grass oil. Under field conditions, the residual activity of the P. nigrum extracts was less than 3 h. When adult L. decemlineata were placed on treated plants exposed to full sunlight for 0, 1.5, and 3 h, leaf damage progressively increased as the main active compound, piperine, was found to degrade by 80% after 3 h. An in vitro polysubstrate monoxygenase (PSMO) enzyme assay, using the substrate methoxyresorufin O-demethylation (MROD), determined that the principal P. nigrum active compound, piperine, is responsible for inhibition of that specific enzyme. The results suggest that Piper extracts could be used effectively as contact botanical insect control agents to protect potato plants from developing L. decemlineata larvae at concentrations less than 0.1%. There is also potential for Piper extracts to control insecticide resistant populations in conjunction with other integrated pest management (IPM) strategies used in conventional and organic agriculture.
使用科罗拉多马铃薯甲虫（Leptinotarsa decemlineata (Say)）的幼虫和成虫，对胡椒科的两种植物——黑胡椒（Piper nigrum L.）和糙叶胡椒（P. tuberculatum Jacq.）的提取物的功效进行了评估。幼虫和初孵幼虫最为敏感；对于4日龄幼虫，测定了糙叶胡椒提取物24小时的半数致死剂量（LD(50)）为0.064%，而用黑胡椒提取物0.05%处理马铃薯（Solanum tuberosum L.，茄科）植株后，一周内幼虫存活率降低了70%。当用糙叶胡椒提取物对科罗拉多马铃薯甲虫的抗药性幼虫品系进行测试时，与对拟除虫菊酯氯氰菊酯的22倍耐受率相比，其耐受率不到2倍。大龄幼虫、预蛹期和成虫对黑胡椒提取物不太敏感；24小时的半数致死剂量（LD(50)）为0.5%（95%置信区间 = 0.36, 0.65）。然而，在田间条件下相同浓度同样有效。在温室中，0.5%的黑胡椒在减少科罗拉多马铃薯甲虫成虫取食方面，与两种单独的植物混合物（大蒜和柠檬草油）组合一样有效。在田间条件下，黑胡椒提取物的残留活性小于3小时。当将科罗拉多马铃薯甲虫成虫放置在经过处理并分别暴露于全光照0、1.5和3小时的植株上时，随着主要活性化合物胡椒碱在3小时后被发现降解了80%，叶片损伤逐渐增加。使用甲氧基试卤灵O - 脱甲基化（MROD）作为底物的体外多底物单加氧酶（PSMO）酶活性测定表明，黑胡椒的主要活性化合物胡椒碱是抑制该特定酶的原因。结果表明，胡椒提取物可有效用作接触型植物源杀虫剂，以保护马铃薯植株免受科罗拉多马铃薯甲虫幼虫侵害，浓度低于0.1%。胡椒提取物还有潜力与常规农业和有机农业中使用的其他综合虫害管理（IPM）策略结合，用于控制抗药性害虫种群。
