Impact of sesquiterpenes from Inula racemosa (Asteraceae) on growth, development and nutrition of Spodoptera litura (Lepidoptera: Noctuidae).
BACKGROUND
The use of botanical pesticides for protecting crops from insect pests has assumed greater importance all over the world owing to growing awareness of harmful effects of indiscriminate use of synthetic pesticides. Inula racemosa Hook. f. (Asteraceae), a medicinally important perennial herb, is rich in sesquiterpenes with many biological activities. The present studies were conducted with the objective to evaluate the sesquiterpenes isolated from I. racemosa for insecticidal activity against Spodoptera litura (F.).


RESULTS
Alantolactone and isoalantolactone isolated from I. racemosa exerted growth inhibitory effects on S. litura. Addition of both the sesquiterpenes to larval diet extended the development period and reduced pupation as well as adult emergence. The dietary utilisation experiments on third-instar larvae of S. litura revealed reduction in consumption and growth rates of larvae as well as efficiency of conversion of ingested and digested food owing to alantolactone and isoalantolactone.


CONCLUSIONS
The root extract of I. racemosa, which is rich in two sesquiterpenes, i.e. alantolactone and isoalantolactone, has the potential for management of S. litura. However, there is a need to understand the specific mechanism of action of these compounds. © 2016 Society of Chemical Industry.
Department of Zoology, Guru Nanak Dev University, Amritsar, Punjab, India.
Mandeep
M
Kaur
Department of Natural Products, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar, Punjab, India.
Rakesh
R
Kumar
Department of Natural Products, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar, Punjab, India.
Deep Patel
DP
Upendrabhai
Department of Natural Products, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar, Punjab, India.
Inder Pal
IP
Singh
Department of Zoology, Guru Nanak Dev University, Amritsar, Punjab, India.
Sanehdeep
S
Kaur
D000818:Animals; D019659:Asteraceae / Q000737:chemistry*; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D012717:Sesquiterpenes / Q000302:isolation & purification / Q000494:pharmacology*; D018411:Spodoptera / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism
D012717:Sesquiterpenes
Inula racemosa; Spodoptera litura; alantolactone; isoalantolactone; sesquiterpenes