Astylus atromaculatus (Spotted maize beetle)

Coleoptera > Melyridae

The larvae live in the soil and feed mainly on decayed vegetable matter. They also feed on newly planted maize seeds, causing damage both before and after germination. The adults feed on pollen but despite sometimes occurring in large numbers, do not usually cause much damage to maize flowers.

Agrotis ipsilon (Black cutworm)

Lepidoptera > Noctuidae

Caterpillars sometimes can cause extensive damage to germinating plants.

Agrotis longidentifera (Brown cutworm)

Lepidoptera > Noctuidae

Caterpillars sometimes can cause extensive damage to germinating plants.

Agrotis segetum (Common cutworm)

Lepidoptera > Noctuidae

Caterpillars sometimes can cause extensive damage to germinating plants.

Agrotis subalba (Grey cutworm)

Lepidoptera > Noctuidae

Caterpillars sometimes can cause extensive damage to germinating plants.

Protostrophus spp. (ground weevils)

Coleoptera > Curculionidae

Adults chew the leaves of young plants, sometimes causing extensive damage when they occur in large numbers.

Adoretus cribrosus (Maize chafer)

Coleoptera > Scarabaeidae

The soil-dwelling larvae occasionally damage roots.

Buphonella nigroviolacea metallica (Maize rootworm)

Coleoptera > Chrysomelidae

The soil-dwelling larvae occasionally damage roots.

Gonocephalum spp.

Coleoptera > Tenebrionidae

Larvae feed on roots but rarely cause much damage.

Wire worms

Coleoptera > Elateridae

The elongate larvae live in the soil and feed on roots. Only occasionally troublesome.

Cicadulina mbila (Maize leafhopper)

Hemiptera > Cicadellidae

Sucks the juices of leaves. Its main damage to the plant is to infect it with Maize Streak Virus which causes yellow streaks to appear on the leaf on either side of the main vein. Damage is mainly to plants younger than six weeks.

Epilachna similis (Grain ladybird)

Coleoptera > Coccinellidae

Larvae and adult beetles feed on the leaves of various grasses including maize. Rarely causes serious defoliation.

Spodoptera exempta (Army worm)

Lepidoptera > Noctuidae

Caterpillars chew the leaves. Can be sudden outbreaks that cause extensive damage.

Spodoptera exigua (Lesser army worm)

Lepidoptera > Noctuidae

Caterpillars chew the leaves.

Busseola fusca (Maize stalk borer)

Lepidoptera > Noctuidae

Young larvae (termed top grubs) eat the young unfurled upper leaves, riddling them with holes that become apparent once the leaves unfurl. The older larvae bore into the stalk.

Heteronychus arator (Black maize beetle)

Coleoptera > Scarabaeidae

The adult beetle gnaws into the underground part of the stalk. Older plants usually survive this attack but young plants often succumb.

Sesamia calamistis (Pink stalk borer)

Lepidoptera > Noctuidae

Larvae bore into the stalk and/or feed on the cob of the plant. This often kills young plants or reduces yields of older plants. The hollow stalks also make older plants susceptible to being snapped off in the wind. Damage to the cob is especially a problem for sweetcorn producers as they have to then have to employ people to pick out the damaged cobs. 

Chilo partellus (Sorghum stem borer)

Lepidoptera > Pyralidae

Larvae bore into cobs and stalk but are usually less abundant and damaging than the Maize Stalk Borer.

Heliothis armigera (American bollworm)

Lepidoptera > Noctuidae

Caterpillars often feed on the silken beard at the apex of the cob and also move on to feeding on the apical kernels. Do not usually cause serious damage.

Rhopalosiphum maidis (Maize aphid)

Hemiptera > Aphididae

Commonly infests isolated plants but is rarely a problem in large fields of maize. Usually sucks on juices from the tassels and silk, on the leaves sheathing the cob, and with heavy infestations, the underside of leaves.