Occurrence of Spodoptera frugiperda (J. E. Smith) (Insecta: Lepidoptera: Noctuidae), commonly known as fall armyworm, in southern India is reported along with associated natural enemies. Severe damage was noticed in Chikkaballapur, Hassan, Shivamogga, Davanagere and Chitradurga during July-August 2018. The incidence ranged from 9.0 to 62.5 percent at various locations, maximum incidence was recorded in Hassan district followed by Chikkaballapur, Davanagere, Shivamogga and Chitradurga. Morphology and molecular based taxonomic tools were used for the identification of this pest. The GenBank accession number MH704433 of Chikkaballapur population was released on 1 st August, 2018 and Barcode obtained from BOLD System-ID: AGIMP054-18. The survey also revealed natural parasitism by egg parasitoids viz., Telenomus sp. (Hymenoptera: Platygastridae) and Trichogramma sp. (Hymenoptera: Trichogrammatidae), gregarious larval parasitoid, Glyptapanteles creatonoti (Viereck) (Hymenoptera: Braconidae) solitary larval parasitoid, Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae), and a solitary indeterminate larval-pupal (Hymenoptera: Ichneumonidae: Ichneumoninae) parasitoid. Spodoptera frugiperda is the first host record for G. creatonoti across the globe. Glyptapanteles creatonoti, being a well established parasitoid of various noctuids in India and Malaysia, was capable of parasitizing S. frugiperda. Besides these, other commonly found bioagents viz., Forficula sp. (Dermaptera: Forficulidae) and entomopathogenic fungus Nomuraea rileyi (Farl.) Samson was also collected in large numbers. We report the natural enemy complex of S. frugiperda for the first time from India. The electro physiological response of Indian population of S. frugiperda male adults to pheromone was established. The studies to manage this pest by any/all means are in progress.
Recent studies proved that the biofumigants could be an alternative to chemical fumigants against stored grain insect pests. For this reason, it is necessary to understand the mode of action of biofumigants. In the present study the prospectus of utilising Lantana camara as a potent fumigant insecticide is being discussed. Inhibition of acetylcholinesterase (AChE) by Coumaran, an active ingredient extracted from the plant L. camara, was studied. The biofumigant was used as an enzyme inhibitor and acetylthiocholine iodide as a substrate along with Ellman's reagent to carry out the reactions. The in vivo inhibition was observed in both dose dependent and time dependent in case of housefly, and the nervous tissue (ganglion) and the whole insect homogenate of stored grain insect exposed to Coumaran. The possible mode of action of Coumaran as an acetylcholinesterase inhibitor is discussed.
Objective
Insecticidal activity of Clerodendrum capitatum extracts against the stored product insect pest, Sitophilus oryzae (L.), Rhyzopertha dominica (F.), and Tribolium castaneum (Herbst) were investigated.
Materials and Methods
Hundred grams of C. capitatum powder was sequentially extracted with a series of solvents of increasing polarity in a Soxhlet apparatus and the extracts were concentrated on rotary evaporator to make it solvent free and the residue dissolved in a known volume of methanol and the solution was assayed for insecticidal activity by the fumigant toxicity. Hexane extract which showed maximum activity was selected for the preparation of herbal formulation and for its insecticidal properties and phytotoxicity. The herbal formulation obtained from leaves of C. capitatum was investigated by GCMS and GC/FID.
Results
Clerodendrum capitatum ethyl extract had a very strong repellent activity to adults of all three major stored grain insects and was significantly repellent at a 1.58 mg/cm2. The hexane extract (oil) had high fumigant activity with LC50 values in the range between 25 and 32 µg/L. A total of 14 components representing 97.8% of the formulation were identified and the main compounds in the formulation were found to be 2-Heptanone, 3-methyl (33.9 %) and Hexahydrofarnesyl acetone (25.3%) followed by 3-Dodecen-1-al (10.2%) and 8-Methyl-1-undecene (4.9%). Further, herbal formulation was found to be highly toxic to mixed age cultures of all three major stored grain insect pests which recorded 80%–90% mortality at dose of 200 µg/L in 24 h exposure, where as 100% mortality achieved at dose of 200 µg/L in 72 h exposure, respectively.
Conclusion
The results indicate that extracts and formulation of C. capitatum has the potential to be developed in to a natural insecticide or repellent for controlling of stored product beetles.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.