First formulation of a botanical active substance extracted from neem cell culture for controlling the armyworm

Abstract

Neem (Azadirachta indica) produces several of compounds known as limonoids, which have an antifeedant effect on insects. These compounds are extremely sensitive to some environmental factors that cause their degradation. Despite this, they are widely used in many formulations of commercial bioinsecticides. We evaluated the photodegradation of the crude extract from A. indica cell culture and designed the formulation of a botanical active substance for controlling insects. The crude extract was subjected to 368 nm UV light for 24 h, and its degradation was examined. Limonoids present in the crude extract were analyzed via high-performance liquid chromatography (HPLC). The composition of some compounds in the extract decreased by 55% after 214 min and 83% after 1440 min. For the insect bioassay, we prepared six formulations containing ethanolic extracts from A. indica cell culture as the active ingredient. The formulation also contained a photoprotector and two stabilizers, emulsified with water, castor oil, and Tween 80. Formulations were subjected to stability tests, and the relative phase separation was assessed. To evaluate their biological activity, the antifeedant index and the affected leaf area on corn infested with Spodoptera frugiperda were determined using laboratory-and field-scale bioassays. Three formulations showed good stability, and two presented the highest antifeedant indices (98.5 and 99.7%) in laboratory-scale bioassays. They provided the greatest field-level protection (leaf areas affected were 0.6 and 1.9%, respectively). Therefore, the emulsion containing 0.76% p/p ethanolic extract, 0.72% 8-hydroxyquinoline, 1.00% anthraquinone and epichlorohydrin, 0.20% Tween 80, and 50/50 aqueous phase/oil phase was selected as the best formulation for the insect biocontroller. This thus addresses the problem of metabolite degradation in the field. To our knowledge, this is the first effective formulation of a botanical active substance for controlling insects using A. indica cell culture extract.

WITHDRAWN: Bioengineering of Neem Colloidal Nano-Emulsion Formulation With Adjuvant for Better Surface Adhesion and Long Term Activity in Insect Control

“…The most common destabilization phenomenon like occulation, creaming, and coalescence etc. are directly related to droplet size 25,26 . The small size of nanoemulsion is desirable in achieving optimal e ciency.…”

Antifeeding effects of azadirachtin on the fifth instar Spodoptera litura larvae and the analysis of azadirachtin on target sensilla around mouthparts

“…Previous research has shown that azadirachtin has a variety of biological effects on insects, such as antifeeding (Tomé et al, 2013), inhibition of growth and development (Lucantoni et al, 2006), avoidance (Bezzar-Bendjazia, Kilani-Morakchi, Maroua, & Aribi, 2017;Liu & Liu, 2006), cytotoxicity (Radhika, Sahayaraj, Senthil-Nathan, & Hunter, 2018), and so on. The antifeedant index and the affected leaf area of corn infected with Spodoptera frugiperda were evaluated by a laboratory and field bioassay by Zuleta-Castro, Rios, Hoyos, and Orozco-S nchez (2017). The results showed that the crude extract of azadirachta had good stability and an antifeedant effect.…”

Video on Mobile Phones as an Effective Way to Promote Sustainable Practices by Facilitating Innovation Uptake in Mali

“…One video described the production and use of a bio-pesticide using Neem and hot pepper. Neem (Azadirachta indica) produces several of compounds known as limonoids, which have an antifeedant effect on insects and are therefore used in the formulation of many commercial biosinsecticides [41]. A second video compared three different ways of applying compost: uniformly, in rows, and in pockets.…”