Aphids mainly feed on young leaves of maize, sorghum, barley, wheat, tobacco, cyperaceae, green beans, millets, papaya, potato, rice, sugarcane and wheat

Image courtesy noldus

Signs of damage

The leaves, leaf sheaths and inflorescence are easily infested with aphids. This makes the leaves to become mottled and distorted, and the inflorescence become sterile.

New growing plants can then remain dwarfed. In the case of heavy attacks, the plants tend to wilt and die. Aphids are also known to be vectors of viral diseases affecting cereals and other crops

These persistent viruses include: barley yellow dwarf, maize leaf fleck and millet red leaf. The non-persistent viruses include abaca mosaic, maize dwarf mosaic and sugarcane mosaic.  .


Aphids appearance

The female aphids normally reproduce without mating, they don’t lay eggs but instead birth live young ones.

  • The first instar nymphs are light green with the tips of the head, antennae and legs slightly darker than the body.
  • The second instar nymphs are pale green with the head, abdomen and antennae darker than the body, the legs are paler with red eyes.
  • At the third stage, the constricted third antenna segment is divided into two segments with the body still pale green but slightly darker on the sides. Legs are darker than the body while the head is dark green.

Image courtesy els landscape

Elongated aphids: The antennae is short, the color varies from yellow green to dark olive green or blue-green. Some of the insects are normally dusted with wax having dark purple areas around the base of the siphunculi. The siphunculi are dark and short with the insect being 0.9-2.4mm.

Aphids’ larvae: They have a yellow green to dark green abdomen without the dark dorsal markings near the siphunculi. They are 0.9-2.4mm..

The aphid adults are winged or unwinged, elongate and measure between 1/25 to 1/12 inch in length. They are yellow green to dark olive green or bluish green having a light powdery covering. During cool weather their color tends to be pale green while during warm weather tend to be darker.


Cultural control methods

  • Burn the crop stubble after the harvest
  • Natural enemies can also control aphids
  • Destruction of weeds to reduce the feed base of aphids.
  • The weeds should be removed below the water level