Articles
Insecticidal activity of a diatomaceous earth and a natural Cuban zeolite against adults of the bean weevil, Acanthoscelides obtectus
Article number
1458_55
Pages
413 – 420
Language
English
Abstract
The bean weevil, Acanthoscelides obtectus (Say) (Coleoptera, Bruchidae), is one of the most serious pests of stored legumes worldwide.
There is a growing global interest in replacing chemical insecticides due to their adverse environmental and health effects, as well as the development of pest resistance.
Many inert dusts, primarily including diatomaceous earth (DE), have been proven effective in controlling stored-product insect pests, while the insecticidal activity of zeolites remains little investigated.
The present study aimed to evaluate the insecticidal activity of DE (Insectosec, Newpharm) and a natural Cuban zeolite (Zeokill, Bioagrotech) against A. obtectus when applied to seeds of different legumes.
Chickpea or lentil samples (80 g) put in cylindrical plastic containers (Ø 6×8 cm) were treated with increasing doses (0, 0.5, 1.0, 2.0, 4.0, 8.0 kg t‑1) of DE or zeolite, infested with 20 newly emerged A. obtectus adults, and maintained at 25±2°C, 60% relative humidity, and at daily periods of 12 h of light (L) and 12 h of dark (D) (L12:D12). The number of dead specimens was recorded at 3, 7, 10, 14, and 21 days of exposure, and the mean percentage of insect mortality was calculated.
For both legumes, the DE and zeolite treatments induced adult mortality, increasing with the dose and exposure time.
On chickpea, the total insect mortality was achieved at the lowest dose tested (0.5 kg t‑1) after 3 and 7 days-exposure to DE and zeolite, respectively.
Similarly, on lentil, the total insect mortality was recorded at 0.5 and 1 kg t‑1 doses after 7-day exposure to DE and zeolite, respectively.
Overall, both inert dusts were effective in controlling A. obtectus at lower doses tested and in short exposure times, with the DE showing a faster insecticidal activity.
Notably, the insecticidal activity of inert dusts can vary depending on the substrate treated, likely due to differences in particle adherence to the seed surface.
There is a growing global interest in replacing chemical insecticides due to their adverse environmental and health effects, as well as the development of pest resistance.
Many inert dusts, primarily including diatomaceous earth (DE), have been proven effective in controlling stored-product insect pests, while the insecticidal activity of zeolites remains little investigated.
The present study aimed to evaluate the insecticidal activity of DE (Insectosec, Newpharm) and a natural Cuban zeolite (Zeokill, Bioagrotech) against A. obtectus when applied to seeds of different legumes.
Chickpea or lentil samples (80 g) put in cylindrical plastic containers (Ø 6×8 cm) were treated with increasing doses (0, 0.5, 1.0, 2.0, 4.0, 8.0 kg t‑1) of DE or zeolite, infested with 20 newly emerged A. obtectus adults, and maintained at 25±2°C, 60% relative humidity, and at daily periods of 12 h of light (L) and 12 h of dark (D) (L12:D12). The number of dead specimens was recorded at 3, 7, 10, 14, and 21 days of exposure, and the mean percentage of insect mortality was calculated.
For both legumes, the DE and zeolite treatments induced adult mortality, increasing with the dose and exposure time.
On chickpea, the total insect mortality was achieved at the lowest dose tested (0.5 kg t‑1) after 3 and 7 days-exposure to DE and zeolite, respectively.
Similarly, on lentil, the total insect mortality was recorded at 0.5 and 1 kg t‑1 doses after 7-day exposure to DE and zeolite, respectively.
Overall, both inert dusts were effective in controlling A. obtectus at lower doses tested and in short exposure times, with the DE showing a faster insecticidal activity.
Notably, the insecticidal activity of inert dusts can vary depending on the substrate treated, likely due to differences in particle adherence to the seed surface.
Authors
I. DIsita, O.M. Pistillo, F. Lo Muzio, A. Asghar, M. Coduti, M. Acquaviva, A.M. Di Palma, G.S. Germinara
Keywords
stored-product insect pests, inert dusts, mortality bioassays, physical control means, IPM
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