Articles
EFFICACY OF LANTANA CAMARA L. AND TEPHROSIA VOGELII HOOK AGAINST SITOPHILUS ZEAMAIS (COLEOPTERA: CURCULIONIDAE) IN STORED MAIZE GRAINS
Article number
679_16
Pages
137 – 143
Language
English
Abstract
The toxic and repellent effects of two tropical plants, Lantana camara L. and Tephrosia vogelii Hook were evaluated against Sitophilus zeamais Motschulsky in stored maize grains.
Five rates (1.0, 2.5, 5.0, 7.5 and 10.0% w/w) of each powdered plant material, an untreated control and a synthetic insecticide (Actellic Super&trade 2% dust) were used to investigate treatment efficacy on mortality of the adult insect (five to eight days old), F1 progeny emergence and repellence against S. zeamais adults.
After 21 days, L. camara and T. vogelii caused 82.7-90.0% and 85.0-93.7% insect mortality, respectively.
The mean lethal exposure times (LT50) to achieve 50% mortality varied from five to six days (7.5-10.0% w/w) to seven to eight days (2.5-5.0% w/w) for both plants.
Probit regression analysis showed a significant relationship between plant powder concentration and insect mortality.
The plant powders and synthetic insecticide reduced adult F1 insects by more than 75% compared to the untreated control. T. vogelii was most repellent to S. zeamais at 7.5-10.0% (w/w), showing that 87.5% of insects were repelled, followed by T. vogelii at 2.5% w/w and L. camara at 10% w/w which showed that 65.0% and 62.5% of insects were repelled, respectively.
The implications of these results are discussed in the context of small-scale farmer usage of these plants for stored product protection and implications on food security and poverty alleviation.
Five rates (1.0, 2.5, 5.0, 7.5 and 10.0% w/w) of each powdered plant material, an untreated control and a synthetic insecticide (Actellic Super&trade 2% dust) were used to investigate treatment efficacy on mortality of the adult insect (five to eight days old), F1 progeny emergence and repellence against S. zeamais adults.
After 21 days, L. camara and T. vogelii caused 82.7-90.0% and 85.0-93.7% insect mortality, respectively.
The mean lethal exposure times (LT50) to achieve 50% mortality varied from five to six days (7.5-10.0% w/w) to seven to eight days (2.5-5.0% w/w) for both plants.
Probit regression analysis showed a significant relationship between plant powder concentration and insect mortality.
The plant powders and synthetic insecticide reduced adult F1 insects by more than 75% compared to the untreated control. T. vogelii was most repellent to S. zeamais at 7.5-10.0% (w/w), showing that 87.5% of insects were repelled, followed by T. vogelii at 2.5% w/w and L. camara at 10% w/w which showed that 65.0% and 62.5% of insects were repelled, respectively.
The implications of these results are discussed in the context of small-scale farmer usage of these plants for stored product protection and implications on food security and poverty alleviation.
Authors
J.O. Ogendo, S.R. Belmain, A.L. Deng, D.J. Walker
Keywords
botanical insecticides, grain storage, mortality, repellence, stored product protection
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