Toxic effects of the neem oil (Azadirachta indica) formulation on the stink bug predator, Podisus nigrispinus (Heteroptera: Pentatomidae)

Abstract

This research investigated the effects of neem oil on mortality, survival and malformations of the nontarget stink bug predator, Podisus nigrispinus. Neurotoxic and growth inhibitor insecticides were used to compare the lethal and sublethal effects from neem oil on this predator. Six concentrations of neem oil were topically applied onto nymphs and adults of this predator. The mortality rates of third, fourth, and fifth instar nymphs increased with increasing neem oil concentrations, suggesting low toxicity to P. nigrispinus nymphs. Mortality of adults was low, but with sublethal effects of neem products on this predator. The developmental rate of P. nigrispinus decreased with increasing neem oil concentrations. Longevity of fourth instar nymphs varied from 3.74 to 3.05 d, fifth instar from 5.94 to 4.07 d and adult from 16.5 and 15.7 d with 0.5 and 50% neem doses. Podisus nigrispinus presented malformations and increase with neem oil concentrations. The main malformations occur in wings, scutellum and legs of this predator. The neem oil at high and sub lethal doses cause mortality, inhibits growth and survival and results in anomalies on wings and legs of the non-traget predator P. nigrispinus indicating that its use associated with biological control should be carefully evaluated.

Insecticidal activity of garlic essential oil and their constituents against the mealworm beetle, Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae)

“…These oils are plants secondary metabolites and include alkaloids, amides, chalcones, flavones, kawapirones, lignans, neolignans or phenols which are important in insect-plant relationships141518. In this sense, essential oils represent an alternative for pest control as repellents, deterrent of oviposition and feeding, growth regulators, and toxicity to insects with low pollution and quick degradation in the environmental1617. Various studies have focused on the possibility of using plant essential oils for application to stored grain to control insect pests192021.…”

Ecotoxicological potential of bordeaux mixture and Neem oil on non-target soil organisms

“…Other studies have reported negative effects on non-target organisms. Neem oil mortality was confirmed in juveniles and adults of the non-target predator Podisus nigrispinus, depending on concentration applied, and they could be compared to a neurotoxic insecticide and growth inhibitor (Zanuncio et al, 2016). It also verified the toxicity of this oil for adults and nymphs of Aphis gossypii (target) and the larva of its natural predator Cycloneda sanguine (non-target).…”

“…This is the main component responsible for anti-food and toxic effects on insects. It also causes deformities in the pupae, increasing in the instar period (which causes aging of the larvae) and reproductive effects (Souza et al, 2015, Zanuncio et al, 2016, Archana et al, 2017. Neem applications ranging from 0.5 to 7% in the control of Bemisia argentifolli, Keratoma tingomarianus, Liriomyza sativae, Sitophilus zeamais and Zabrotes subfasciatus; Gyropsylla spegazziniana are recommended (Fernandes et al, 2006, Silva et al, 2015, Formentini et al, 2016.…”

“…The risks of Bordeaux mixture for non-target arthropods are considered low (Bengochea et al, 2014). Neem oil has been shown exceptionally safe for beneficial organisms, mainly because it is very selective (Zanuncio et al, 2016;Archana et al, 2017).…”

Acute toxicity evaluation of mixture of neem (Azadirachta indica) and moringa (Moringa oleifera) seed oils in rats

“…The usual beginning in any toxicological evaluation is the assessment of the acute toxicity that is the effects of a single dosage of the chemical. Botanical insecticides have eco-toxicological advantages compared to traditional synthetic insecticides because they can have favourable eco-toxicological properties (low human toxicity), rapid degradation and reduced environmental impact which make them suitable insecticides for organic agriculture (Zanuncio et al, 2016).…”