Soil application of azadirachtin and 3‐tigloyl‐azadirachtol to control western flower thrips, Frankliniella occidentalis (Thysanoptera: Thripidae): translocation and persistence in bean plants

Abstract

To study the systemic effects of active neem ingredients, the substrate of bean plants was treated with a 170 g kg(-1) azadirachtin (NeemAzal-U; Trifolio-M GmbH, Lahnau, Germany, registration pending). This product was used at a dose rate of 10 mg AZA (azadirachtin a) and 1.2 mg 3-tigloyl-azadirachtol (azadirachtin b) per treated bean plant. Afterwards, the translocation and persistence of AZA and 3-tigloyl-azadirachtol and the effects on western flower thrips, Frankliniella occidentalis (Pergande), were studied. Residues of AZA and 3-tigloyl-azadirachtol from substrates with different contents of organic matter [pure culture substrate (CS), CS-sand mixture] and from various plant parts were quantified by high-performance liquid chromatography-mass spectrometry (HPLC-MS). The dissipation trends of AZA and 3-tigloyl-azadirachtol were similar within the same substrates. A slower decline of both active ingredients was measured with CS than with CS-sand mixture. Residue analysis of the bean plants showed that only small proportions of the initial amounts of AZA and 3-tigloyl-azadirachtol applied to the substrate were present in the plant (0.3-8.1%). Variable amounts of residues of the active components in relation to plant parts and time of analysis indicated a different translocation pattern for the two active ingredients. Higher residues of the active ingredients were found in roots and stems after neem application using CS, whereas higher residues were found in leaves after CS-sand mixture treatments. Mortality of F. occidentalis after NeemAzal-U soil applications reached up to 95% on CS-sand mixture, compared with 86% in CS.

Additive and synergistic interactions amongst Orius laevigatus (Heteroptera: Anthocoridae), entomopathogens and azadirachtin for controlling western flower thrips (Thysanoptera: Thripidae)

“…They can be used in combinations with entomopathogens that are "compatible" (causing mortality ˂ 20%) and their joint efficacy can potentially benefit from synergistic interaction (Mohan et al 2007, Islam et al 2010. However, since the active ingredient azadirachtin is susceptible to photodegradation by UV radiation, soil application is advantageous to minimize exposure to sunlight, and for soil treatments water based formulations of azadirachtin have been proven to be most efficient in controlling pests (Thoeming et al 2006, Karanja et al 2015 Entomopathogenic fungi (EPF) such as Metarhizium anisopliae (Metschnikoff) Sorokin (Hypocreales: Clavicipitacea) has also been described as an efficient biocontrol agents against western flower thrips (Ansari et al 2007(Ansari et al , 2008. The relative safety and specificity of these fungal pathogens may enhance their acceptance for use in pest management programs (Gao et al 2012).…”

The combined effect of soil‐applied azadirachtin with entomopathogens for integrated management of western flower thrips

“…), Ceratothripoides claratris (Thoeming and Poehling ) and WFT (Thoeming et al. ; Cloyd ). The active ingredient of neem products, azadirachtin (AZA), can affect the behaviour and physiology of different target insects (Mitchell et al.…”

Effect of Aqueous Extract of Neem (Azadirachta Indicia) Leaves on Plant Development and Liver Enzymes in Rats.

“…Azadiractha indica is a tetranortriterpenoid or limonoid, which is familiar to steroids [9]. Extracts from neem leaves, roots, fruits, seeds and barks comprise with properties of biocids properties and utilize for soil amendments.…”