Theory question 106
Crop Pests(a) Outline the life cycle of the bean beetle
(b)(i) Describe briefly four damages done by cotton stainer to cotton plants on the field (ii) Name four alternate hosts of cotton stainer.
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(a) Bean beetle (Callosobruchus maculatus) has complete metamorphosis: female lays eggs on the seed/pod surface; larva hatches and bores into the seed, feeding inside; it pupates inside the seed; adult emerges through a round hole; the cycle takes about 3–4 weeks and repeats in store
(b)(i) Any four: sucks sap from developing bolls and seeds; seeds shrivel and lose viability/oil; stains the lint yellow/brown, lowering quality; introduces fungi that cause internal boll rot; causes boll shedding
(ii) Any four: okra; kenaf; baobab; silk cotton tree (kapok); hibiscus/roselle; Sida and other wild Malvaceae
Follow the life cycle stage by stage.