Effect of NeemAzal and other neem products on mortality, fecundity and frass activity of the larger grain borer Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) infesting maize.

Abstract

Two NeemAzal products from Trifolio GmbH, Germany, and neem oil and neem seed cake powder of the Kenyan neem tree were tested for their efficacy against the storage pest P. truncatus in the laboratory at (a) low, (b) medium and (c) high rates, containing approximately 1.5, 3 and 6 mg azadirachtin A/kg maize, respectively. The maize samples were stored in 250 ml glass jars at 30°C and 70% relative humidity. After one month of storage, NeemAzal PC KG 01 (0.1% azadirachtin A) at all the tested rates and neem seed oil at high rates caused more than 80% mortality compared with 4% in the control. The two compounds also reduced weight loss to less than 20% of the loss in the control. Neem oil at high rates resulted in the highest mortality after 24 h. Most of the mortality caused by the NeemAzal PC KG 01 at all rates occurred within 7 days of treatment. Insect population increase was completely inhibited by rates of more than 7.5 ml/kg (approx. 22.5 mg azadirachtin A/kg maize) of neem oil and 3 mg azadirachtin A/kg maize of NeemAzal PC KG 01, while the lower dosage levels of neem oil also resulted in significantly fewer progeny compared with the untreated control. Neem oil caused larval mortality in their early developmental stages within the grains. These results are discussed in relation to the existing widely varied reports on the same subject.

Comparative efficacy of NeemAzal and local botanicals derived from Azadirachta indica and Plectranthus glandulosus against Sitophilus zeamais on maize

“…The toxic action of NSP and P. glandulosus powder was slower than that of NeemAzal powder and NSO. Our result on the insecticidal efficacy of NeemAzal against S. zeamais is different from that of Ogemah et al (2002). These authors reported that at the rate of 6 g/kg, NeemAzal powder caused complete mortality of P. truncatus on maize within 28 days, while in our study it caused 98% mortality of S. zeamais within 14 days.…”

“…These results are similar with the findings of other workers. NeemAzal powder, NSO and NSP inhibited F 1 progeny of P. truncatus (Ogemah et al 2002). Crude powders from Lantana camara and Tephrosia vogelii reduced F 1 progeny of S. zeamais by over 75% (Ogendo et al 2004).…”

“…Several neem-based commercial insecticides are available, including Azatin, Bioneem, Neemies, Safer's ENI, RD-Repelin, Neemguard, Neemark, Neemazal, Oikos 32 EC (Cóndor 2007;Isman and Akhtar 2007;Kavallieratos et al 2007;Akhtar et al 2008). NeemAzal powder, a mixture of SilicoSec and azadarachtin (0.1%) is produced in Germany, and it can greatly reduce maize damage caused by Prostephanus truncatus Horn (Coleopera: Bostrichidae) during storage (Ogemah et al 2002). The insecticidal activity of neem products is well documented (Schmutterer 1990;Kontodimas et al 2004;Athanassiou et al 2005;Isman 2006; Kavallieratos et al 2007).…”