Bioefficacy of enhanced diatomaceous earth and botanical powders on the mortality and progeny production of Acanthoscelides obtectus (Coleoptera: Chrysomelidae), Sitophilus granarius (Coleoptera: Dryophthoridae) and Tribolium castaneum (Coleoptera: Tenebrionidae) in stored grain cereals

Abstract

Food losses caused by insects during postharvest storage are of paramount economic importance worldwide, especially in Africa. Laboratory bioassays were conducted in stored grains to determine the toxicity of powders of Eugenia aromatica and Moringa oleifera alone or combined with enhanced diatomaceous earth (Probe-A® DE, 89.0% SiO2 and 5% silica aerogel) to adult Sitophilus granarius, Tribolium castaneum and Acanthoscelides obtectus. Adult mortality was observed up to 7 days, while progeny production was recorded at 6–10 weeks. LD50 and LT50 values for adult test insects exposed to plant powders and DE, showed that A. obtectus was the most susceptible towards the botanicals (LD50 0.179% and 0.088% wt/wt for E. aromatica and M. oleifera, respectively), followed by S. granarius. Tribolium castaneum was most tolerant (LD50 1.42% wt/wt and 1.40% wt/wt for E. aromatica and M. oleifera, respectively). The combined mixture of plant powders and DE controlled the beetles faster compared to the plant powders alone. LT50 ranged from 55.7 h to 62.5 h for T. castaneum exposed to 1.0% M. oleifera and 1.0% DE, and 0.5% E. aromatica and 1.0% DE, respectively. Botanicals caused significant reduction of F1 adults compared to the control. Combined action of botanical insecticides with DE as a grain protectant in an integrated pest management approach is discussed.

Bioactivities of patchoulol and phloroacetophenone from Pogostemon cablin essential oil against three insects

“…Such a difference of insecticidal activity against various insect species is common. [47] Chen et al [48] found that the essential oil of Amomum villosum Lour. showed fumigant toxicity to red flour beetles but was inactive to cigarette beetles.…”

Plant‐Derived Substances Used Against Beetles–Pests of Stored Crops and Food–and Their Mode of Action: A Review

“…Adarkwah, Obeng‐Ofori, Hörmann, Ulrichs, and Schöller () investigated alternative control strategies of pests attacking stored grains. They used plant powder from Eugenia aromatica and Moringa oleifera , which caused significant mortality of the adult beetles ( S. granarius , T. castaneum and A. obtectus ) and reduction of F 1 adults compared with the control.…”

α-Pinene, Caryophyllene and β-Myrcene from Peucedanum terebinthaceum Essential oil: Insecticidal and Repellent Effects on Three Stored-Product Insects

“…α-Pinene exhibited great fumigant toxicity to three insect species, with LC50 (the concentration lethal to half of given insect species over a certain time) values of 12.15, 38.07 and 1.43 mg/L air for T. castaneum, L. serricorne and L. bostrychophila respectively. The fumigant toxicity of α-pinene to insect pests has been confirmed, such as Hypothenemus hampei [53], Sitophilus granarius [54] and Callosobruchus chinensis [55]. And it has been reported that essential oils of 10 species of Myrtaceae were toxic to T. castaneum in the fumigation, all of which contained α-pinene within a range of 0.2% -32.5% [56].…”