Peas

Pests of Field Crops in Southern Africa

PEAS

(Pisum sativum, Fabaceae)

Text Box: See general section. Bollworm are invariably found in the pea pods, which they enter close to the calyx end. Bollworm is of particular importance in sugar snap peas grown for export, since the infestation often goes undetected. TOP

Text Box: See general section. This pest is a fairly recent introduction to peas, and has been described in the general section. Attack is often in the seedling stage. As with some of the other vegetables, since the leaves are not the plant part being consumed, it would be better if possible to leave the pest untreated and allow it to come under natural control as far as possible. Another species of leafminer, Phytomyza horticola, also attacks peas, and the long mines are usually located on older leaves. Damage is seldom significant. TOP

African Bollworm

Liriomyza Leafminer

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Þ Lesser Armyworm

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Liriomyza Leafminer

African Bollworm

Text Box: See general section. The main culprit species in peas are the Frankliniella spp., which soon become abundant in the flowers. They cause a peculiar damage symptom that is related to the laying of eggs in the very young pods. This is not unlike that recorded for cold damage – white flower-like markings surrounding a tiny raised “pimple” in which the egg can be detected by microscopic means. Any marks of this sort render the peas unsuitable for export markets. In addition, their feeding may result in scarring of the pod tissue. The thrips can generally be found hiding beneath the flower bract that is retained when the pods begin to grow. Frankliniella spp. continue to breed throughout the winter months, although at a slower rate and in reduced populations. Peas, however, provide a very suitable winter host for the pest. TOP

Entrance hole of African bollworm.

Liriomyza flies on leaf with characteristic stippling damage.

Thrip damage to pea pod. (Photo: W Cranshaw, Colorado State Univ. Bugwood.org)