S-Space College of Agriculture and Life Sciences (농업생명과학대학) Dept. of Agricultural Biotechnology (농생명공학부) Theses (Ph.D. / Sc.D._농생명공학부)
Insecticide Resistance Monitoring and Resistance-Breaking Control Strategies Using Plant-Derived Active Constituents against Major Vectors
- 농업생명과학대학 농생명공학부
- Issue Date
- 서울대학교 대학원
- mosquito ; cockroach ; chigger mite ; natural insecticides ; natural repellent ; cassia bark oil ; star anise oil ; eucalyptus oil ; metabolic detoxification enzymes ; insecticide resistance ; septic tank
- 학위논문 (박사)-- 서울대학교 대학원 : 농생명공학부, 2013. 8. 안용준.
- Vectors are related with various diseases on human, such as malaria (Anopheles sinensis (L.)), Japanese encephalitis (Culex tritaeniorhynchus (L.)), yellow fever (Aedes albopictus (L.)), dengue hemorrhagic fever (Ae. albopictus), filariasis (Ae. albopictus), allergic reaction (Blattella germanica (L.)), and tsutsugamushi disease (Leptorombidium pallidum (L.)), as well as nuisance insect pests (Culex pipiens pallens Foskal). Continued and repeated use of conventional insecticides such as organophosphorus and carbamates, pyrethroids has often resulted in the widespread development of resistance and has undesirable effects on nontarget organisms and environment. Particularly, widespread insecticide resistance has been a major obstacle in the cost-effective integrated vector management program. Therefore, there is critical need for the development of safe and effective control alternatives to establish rational resistance management strategy for vectors.
Biocides from plants or plant essential oils have been suggested as potential alternatives for vector control largely because they constitute a potential source of bioactive chemicals that have been perceived by the general public as relatively safe, pose fewer risks to the environment, with minimal impacts to animal and human health. They often act at multiple and novel target sites, thereby reducing the potential for resistance.
In this studies for insecticide resistance pattern of two mosquito species, Cx. p. pallens and Cx. tritaeniorhynchus, marked regional variations of insecticide susceptibility were observed. Extremely high to low levels of insecticide resistance were observed against Cx. p. pallens: bifenthrin, resistance ratio (RR) = 1–521
β-cyfluthrin, RR = 16–397
α-cypermethrin, RR = 9–343
deltamethrin, RR = 1–40
etofenprox, RR = 2–42
permethrin, RR = 3–46
chlorpyrifos, RR = 2–675
fenitrothion, RR = 0.5–364
fenthion, RR = 2–360. Interestingly, field populations of Cx. tritaeniorhynchus collected from agricultural areas showed high to extremely high resistance to pyrethroids than those from non-agricultural areas indicating that Cx. tritaeniorhynchus population was repeatedly exposed to various insecticides for agricultural pests and thats why resistance of Cx. tritaeniorhynchus populations from agricultural areas were higher than those from non-agricultural areas. Similar results have been observed in cockroaches. Extremely high to high levels of regional resistance patterns were obtained from bifenthrin (RR, 46–159), deltamethrin (RR, 61–268), and esfenvalerate [RR, 70–270
except for BR-BG females (RR, 20) and GR-BG females (RR, 24)].
To develop effective control strategies for insect resistant mosquitoes, an assessment was made of the toxicity of binary mixtures of Bacillus thuringiensis var. israelensis (Bti) and three essential oil major constituents [(E)-cinnamaldehyde (CA) from cassia bark oil, anethole (AN) from star anise oil and eugenol (EU) from clove bud oil] to third instar larvae from bamboo forest-collected Ae. albopictus and rice paddy field-collected An. sinensis. Binary mixtures of Bti and CA, AN, or EU were significantly more toxic than either Bti, CA, AN or EU alone. Based on the co-toxicity coefficient (CC) and synergistic factor (SF), the three binary mixtures operated in a synergy pattern (CC, 140.7–368.3 and SF, 0.0007–0.0010 for Ae. albopictus
CC, 75.1–245.3 and SF, 0.0008–0.0017 for An. sinensis).
To find new control agents from plant for overcoming insecticide resistance of B. germanica, insecticidal activity of Cyperus rotundus (L.) rhizome was assessed against females of then insecticide-susceptible KSS strain and two field-collected SEL and DJN colonies of B. germanica using a contact and vapor-phase mortality bioassay. p-Cymene, nerol, linalool, o-cymene, (S)-(–)-citronellal, (1S)-(–)-camphor, terpinolene, and m-cymene (LD50, 0.29–0.47 mg/cm2) exhibited high contact-fumigant toxicity against susceptible cockroach females. The toxicity of these compounds was virtually identical against females from two strains, SEL and DJN females with resistant to six acetylcholinesterase inhibitors (RR, 9–154) and three pyrethroids (RR, 12–195). These results indicate that the monoterpenoids and the test insecticides do not share a common mode of action or elicit cross-resistance. In vapor-phase mortality bioassay, these monoterpenoids were consistently more toxic in closed versus open containers against SEL females, indicating that their mode of delivery was, in part, a result of vapor action.
An assessment of plant-derived materials was made of the repellency to B. germanica females and L. pallidum larvae. C. rotundus rhizome steam distillate and rhizome constituents were evaluated against against B. germanica females and males. The repellent principles of C. rotundus rhizome were determined to be the sesquiterpenoid zerumbone (ZER) and the monoterpenoids 1,8-cineole, limonene, pinocarveol, and verbenone. In filter-paper choice assays with 163.1 μg/cm2, ZER, 1,8-cineole, (+)-(E)-myrtanol, and (−)-(Z)-myrtanol exhibited complete (100%) repellency and were significantly more effective than deet. At 81.5 μg/cm2, a significant increase in repellency was produced by binary mixtures of ZER and 1,8-cineole, (+)-(E)-myrtenol, or (−)-(Z)-myrtenol (30:70, 50:50, and 70:30 ratios by weight) and repellency of these mixtures (85–96%) was more pronounced than that of each individual compound (57–61%). The optimum ZER content was determined to be more than 50%. In Ebeling choice box assays at 652.4 μg/cm2, ZER exhibited complete repellency 10 h posttreatment and was just as effective as deet. (−)-(E)-Pinocaveol, (−)-(Z)-myrtanol, and (+)-(E)-myrtanol gave 100% repellency at 8 h. Repellency of ZER, (+)-(E)-myrtanol, (−)-(Z)-myrtanol, and (1S)-(−)-verbenone to unantennectomized and antennectomized males differ significantly, indicating that the chemoreceptors involved in this behavioral response are probably located on the antennae.
The repellency of cassia bark, eucalyptus, star anise oils and commercial repellents against main vector of L. pallidum larvae were assessed. Based on the median repellent concentration (RC50) values, (E)-cinnamaldehyde, (E)-anethole, cassia bark oil, and star anise oil (RC50, 0.95–1.52 mg/cm2) exhibited significantly more potent repellency than DEET (3.85 mg/cm2). (E)-cinnamaldehyde, (E)-anethole, cassia bark oil, 1,8-cineole, and star anise oil were ~43, 16, 11, 8, and 4 times more effective than IR3535 (CC50, 6.51%) as judged by the median climbing distance-disturbing concentration (CC50) values. The median residual duration time of repellency (RT50) was significantly more pronounced in DEET (RT50, 323 min) than in all essential oils and constituents (108–167 min).
In conclusion, cassia bark, eucalyptus, star anis essential oil-derived preparations and C. rotundus methanol extract-derived preparations could be useful as insecticides and/or repellents in the control of the vector populations, particularly in the light of their activity against the insecticide-resistant vectors. For practical use of these materials as novel insecticides and repellents to proceed, further research need to establish their human safety. In addition, their effects on nontarget organisms and the aquatic or indoor environments need to be established. Lastly, formulations for improving insecticidal and repellent potency and stability need to be also developed.