Normal view MARC view ISBD view

Maize storage insects (Sitophilus zeamais and Prostephanus truncatus) prefer to feed on smaller maize grains and grains with color, especially green

By: De Groote, H. A. J.
Contributor(s): De Groote, B | Bruce, A.Y | Marangu, C | Tadele Tefera.
Material type: materialTypeLabelArticlePublisher: New York : Elsevier, 2017Subject(s): Maize | Sitophilus zeamais | Prostephanus truncatusOnline resources: Access only for CIMMYT Staff In: Journal of Stored Products Research v. 71, p. 72-80Summary: Maize is the major food staple in Eastern and Southern Africa, and since production is seasonal, on-farm storage is practiced by farmers. Because stored maize is susceptible to pests, improved storage methods are being developed which need to be evaluated for their effectiveness in reducing losses. The standard count and weigh method (CWM) assumes storage insects attack grains of different sizes in equal measure, although this has not been tested. This study therefore analyzed storage insects’ feeding preferences for maize grains of different sizes. Maize grain was sieved and split into four size categories, colored with food dyes, remixed, and distributed into 48 jars, each with about 300 g of grain, artificially infested with maize weevils (Sitophilus zeamais) or larger grain borers (Prostephanus truncatus), 40 insects per jar. After two months, the grains were separated into their size categories (visually, by color), and grain damage and weight loss was estimated with the CWM. Results show that storage insects have a preference for feeding on smaller, rather than larger grains; and on colored rather than uncolored grains. Small-sized and colored grains were more likely to be perforated by insects and suffered more weight loss. This preference, observed for both species, is more pronounced in S. zeamais, who also distinguish between different colors, and prefer green. The size effect is, however, comparatively small and the average weight loss calculated by a size-adjusted formula is not significantly different from that calculated by the standard CWM. However, the resulting differences in weight losses between grains of different sizes are small. Weight loss calculated by weighted CWM, while in principle more accurate, does not in practice lead to significantly different estimates. Therefore, the results do not warrant a change in the conventional CWM for weight loss in stored grain.
List(s) this item appears in: Dr. De Groote
Tags from this library: No tags from this library for this title. Log in to add tags.
    average rating: 0.0 (0 votes)
Item type Current location Collection Call number Status Date due Barcode Item holds
Article CIMMYT Knowledge Center: John Woolston Library

Lic. Jose Juan Caballero Flores

 

CIMMYT Staff Publications Collection Available
Total holds: 0

Peer review

Maize is the major food staple in Eastern and Southern Africa, and since production is seasonal, on-farm storage is practiced by farmers. Because stored maize is susceptible to pests, improved storage methods are being developed which need to be evaluated for their effectiveness in reducing losses. The standard count and weigh method (CWM) assumes storage insects attack grains of different sizes in equal measure, although this has not been tested. This study therefore analyzed storage insects’ feeding preferences for maize grains of different sizes. Maize grain was sieved and split into four size categories, colored with food dyes, remixed, and distributed into 48 jars, each with about 300 g of grain, artificially infested with maize weevils (Sitophilus zeamais) or larger grain borers (Prostephanus truncatus), 40 insects per jar. After two months, the grains were separated into their size categories (visually, by color), and grain damage and weight loss was estimated with the CWM. Results show that storage insects have a preference for feeding on smaller, rather than larger grains; and on colored rather than uncolored grains. Small-sized and colored grains were more likely to be perforated by insects and suffered more weight loss. This preference, observed for both species, is more pronounced in S. zeamais, who also distinguish between different colors, and prefer green. The size effect is, however, comparatively small and the average weight loss calculated by a size-adjusted formula is not significantly different from that calculated by the standard CWM. However, the resulting differences in weight losses between grains of different sizes are small. Weight loss calculated by weighted CWM, while in principle more accurate, does not in practice lead to significantly different estimates. Therefore, the results do not warrant a change in the conventional CWM for weight loss in stored grain.

Text in English

There are no comments for this item.

Log in to your account to post a comment.

Click on an image to view it in the image viewer

International Maize and Wheat Improvement Center (CIMMYT) © Copyright 2015. Carretera México-Veracruz. Km. 45, El Batán, Texcoco, México, C.P. 56237.
Monday –Friday 9:00 am. 17:00 pm. If you have any question, please contact us at CIMMYT-Knowledge-Center@cgiar.org

Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT) © Copyright 2015. Carretera México-Veracruz. Km. 45, El Batán, Texcoco, México, C.P. 56237.
Lunes –Viernes 9:00 am. 17:00 pm. Si tiene cualquier pregunta, contáctenos a CIMMYT-Knowledge-Center@cgiar.org