Efficacy of Insect Growth Regulators as Grain Protectants against Two Stored-Product Pests in Wheat and Maize

Abstract

Insect growth regulators (IGRs) (two juvenile hormone analogues [fenoxycarb and pyriproxifen], four chitin synthesis inhibitors [diflubenzuron, flufenoxuron, lufenuron, and triflumuron], one ecdysteroid agonist [methoxyfenozide], and one combination of chitin synthesis inhibitors and juvenile hormone analogues [lufenuron plus fenoxycarb]) were tested in the laboratory against adults of Prostephanus truncatus in maize and against adults of Rhyzopertha dominica in wheat. The tested IGRs were applied in maize at three doses (1, 5, and 10 ppm) and assessed at three temperature levels (20, 25, and 30°C) in the case of P. truncatus, while in the case of R. dominica the above doses were assessed only at 25°C in wheat. In addition to progeny production, mortality of the treated adults after 14 days of exposure in the IGR-treated commodities was assessed. All IGRs were very effective (>88.5% suppression of progeny) against the tested species at doses of $ 5 ppm, while diflubenzuron at 25°C in the case of P. truncatus or lufenuron and pyriproxyfen in the case of R. dominica completely suppressed (100%) progeny production when they were applied at 1 ppm. At all tested doses, the highest values of R. dominica parental mortality were observed in wheat treated with lufenuron plus fenoxycarb. Temperature at the levels examined in the present study did not appear to affect the overall performance in a great extent of the tested IGRs in terms of adult mortality or suppression of progeny production against P. truncatus in treated maize. The tested IGRs may be considered viable grain protectants and therefore as potential components in stored-product integrated pest management.

Mobility of Stored Product Beetles after Exposure to a Combination Insecticide Containing Deltamethrin, Methoprene, and a Piperonyl Butoxide Synergist Depends on Species, Concentration, and Exposure Time

“…The use of the insect growth regulator (IGR) methoprene for direct application to stored grains, and as structural treatments in storage and processing facilities, has been reported in on-going projects for more than 20 years [1][2][3][4][5]. In general, methoprene and IGRs can be reliable alternatives to traditional neurotoxic insecticides including organophosphorous (OP) and pyrethroid compounds [3,6].…”

“…Methoprene is effective for control of R. dominica and external feeders of stored grains [10,11], and for application to surface substrates [2]. Exposure to methoprene may also reduce fecundity of exposed parental adults [1,6,[12][13][14].…”

Residual efficacy of methoxyfenozide applied on different grain commodities for the control of three stored-product insect pests

“…However, very few studies have evaluated the potential of ecdysteroid agonists against stored-grain insect pests (Oberlander et al, 1998;Kostyukovsky et al, 2000;Kavallieratos et al, 2012;Ali et al, 2016Ali et al, , 2017. Methoxyfenozide, an ecdysteroid agonist, is the member of the diacylhydrazine class (Carlson et al, 2001), novel and potent molt-accelerating compound that targets Lepidoptera (Enríquez et al, 2010), but is harmless to beneficial insects.…”

Disinfestation techniques for major cereals: A status report

“…In biorational approaches, biological materials such as the plant‐ and animal‐derived products are used, or the physical or biological environment of the pest is modified (Phillips & Throne, 2009). It includes modified or controlled atmosphere treatments, use of entomopathogens or plant‐derived products, insect growth regulators (IGRs), and pheromones (Chambers, 1990; Kavallieratos, Athanassiou, Vayias, & Tomanovic, 2012). The natural predators of stored product pests are also included in the biorational approaches.…”