Sorghum

Pests of Field Crops in Southern Africa

SORGHUM

(Sorghum vulgare, Graminaceae)

Text Box: See general section. Occasionally, the bollworm (or earworm as it may be more appropriately called in this case) can cause severe damage in sorghum by feeding on developing heads. Larvae vary in colour, but are often dark in this crop, and may not be immediately noticeable owing to their habit of feeding well within the heads. Small whitish frass pellets are a good indication of their presence. More open-headed varieties are less prone to infestation. The only recommended insecticide for many years has been endosulfan. TOP

Text Box: Armyworm is described under the maize section, and in outbreaks will attack all graminaceous crops, including sorghum. Crop loss can be almost total if the crop is still very small, and preventative measures are not taken. TOP

African Bollworm

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Þ Armoured Bush Crickets

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Text Box: Sorghum is susceptible to soil nematode populations, and in sandy soils they may be the cause of poorly-growing, yellowing crops. TOP

Þ Sorghum Midge

Þ Sorghum Shootfly

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African Bollworm

Text Box: Various species of bugs have been recorded feeding on developing sorghum grains. Amongst these are the green stinkbug (Nezara viridula), cotton stainers (Dysdercus spp.), the spectacularly coloured “blue bugs” (Calidea spp.), small Mirid bugs (Eurystylus spp.) and Coreid bugs such as Anoplocnemus curvipes. As with most of the pests in this crop, these bugs are usually more severe in late-planting situations. TOP

Lygus bug (above) and Mirid bug (below) in sorghum seed head.

Bollworm on Sorghum developing flower head. (Photo: J Van Den Berg.)