Antifeedant and Toxic Effects of a Neem (Azadirachta indica A. Juss)-Based Formulation Neemix® Against Nezara viridula (L.) (Hemiptera: Pentatomidae)

Abstract

The antifeedant activity of Neemix 4.5 EC, a commercial formulation of azadirachtin from the neem tree (Azadirachta indica A. Juss), was tested against adult Nezara viridula (L.) in the laboratory using a cowpea pod-dip method. A toxicity assay was conducted by dipping fourth-instar nymphs. Feeding by adults was significantly reduced in treated pods compared with controls, based on counts of salivary deposits on pod surfaces, inside pod walls and on seeds. The antifeedant effect of azadirachtin was significantly greater on pods treated with 5% aqueous solution than on those treated with 0.5%, indicating that the antifeedant activity was related to concentration. Bugs were initially repelled by Neemix before approaching treated pods to feed. The LC50 for nymphs was 61% (27450 ppm azadirachtin) at 2 d and ranged from 1.8 to 6.2% (810 to 2790 ppm) at 5 d post-treatment, which indicated that neem was slow acting. Sublethal treatment of nymphs disrupted molting and caused morphological defects in adults. Development time to adulthood also was prolonged, and longevity of females was reduced by neem treatments. Azadirachtin may provide an effective component of a comprehensive management program for N. viridula.

Assessment Of The Effects Of Time, Synthetic And Botanical Insecticides Spray Regimes On The Abundance Of Predators In Cowpea Production In Kebbi State Of Nigeria

“…Their presence in both the unsprayed plots and those of the botanical insecticide plots is an indication of the relative harmlessness of this type of insecticide on them. This result is in agreement with the work of [18] whose work found no effect of neem on the predatory activities of Coccinellidae spp. on N. viridula eggs and suggested neem as an important component of IPM on this particular insect pest.…”

“…The finding of this study is in agreement with those of [24] who reported 20% increase in asilids abundance in organic fields compared to the conventional farming fields (which use chemical pesticides). Apart from repelling both adult and larvae, disrupting their development processes including sterility, nke is known to affect insect pests in various other ways such as causing confusion (immobilization) in the behaviour of adults [18]. The effect of this is to enhance predation as the prey becomes easier to capture.…”

Effect of the aqueous extracts of the seeds of Talisia esculenta and Sapindus saponaria on fall armyworm

“…Understanding the mechanism of action of the aqueous extracts on the insect, important to would be understand. It is also important to search insecticide molecules to generate new synthetic products and to obtain natural insecticides for direct use, to produce commercial formulation (Abudulai et al, 2003) or that can be expressed in plants acting as molecular defenses against herbivores insects (Peumans and Van Damme, 1998). …”

Influence of weeding regime and neem seed extract on the population of insect pests and yield of cabbage in the Guinea savannah zone

“…There is, therefore, the need for novel and alternative pest control strategies that are cheaper to use and also less detrimental to the environment. Extracts from the neem tree, Azardirachta indica A Juss have deterrent and insecticidal properties against over 400 insect pests and could be used for pest control in cabbage (Schmutterer, 1985;Abudulai et al, 2004). The extracts act as contact and stomach poisons, and disrupt the development of eggs, larvae, pupae or prevent moulting of larvae or nymphs (Singh, 1994;.…”

“…The neem tree is ubiquitous in Ghana and can therefore be a cheap source of insecticides for pest control in cabbage and other crops. Moreover, neem is non-toxic to mammals and also benign to nontarget organisms (Ascher, 1993;Abudulai et al, 2004).…”