Combined Effect of Diatomaceous Earth and Insect Growth Regulators Against Trogoderma granarium (Coleoptera: Dermestidae)
Muhammad Awais*, Muhammad Zeeshan, Mansoor-ul-Hasan, Muhammad Sagheer, Muhammad Usman Asif, Qurban Ali, Shah Zaman
Grain Research, Training and Storage Management Cell, Department of Entomology, University of Agriculture, Faisalabad-38000, Pakistan
Diatomaceous earth (DE) and two insect growth regulators (IGRs) were tested under laboratory conditions against khapra beetle (Trogoderma granarium). Khapra beetle is a severe pest of stored products and causes heavy losses. Three dose levels of both IGRs (lufenuron and tebufenozide) and DE were used alone and in combinations. Twenty-three instar larvae of khapra beetle were released on treated and untreated wheat grains. Data of larval mortality was recorded after 7, 14 and 21 days, while adult emergence was observed after 14 and 30 days. The progeny production was observed after 60 days. The mortality rates of 84.9%, 66.4%, 41.5% and 91.6% were recorded in case of DE, lufenuron, tebufenozide and combined treatment (lufenuron + DE), respectively, at their highest dose rates compared to control, revealing the highest mortality rate in combined treatment. Similarly, minimum pupation of 1.22 and minimum adult emergence of 0.22 were also observed in combined treatment of lufenuron and DE at their maximum dose rates. Adult progeny production data showed that the highest reduction of 64% was determined with combined application of lufenuron and DE compared to control. The lufenuron and DE were found most appropriate against the khapra beetle, not only alone but also combined. Overall, the outcomes of the present work prominently specify that the combined use of DE and IGRs is highly operative and beneficial against stored grain insect pests.