Common names:
|
Aphids (English); omudjenene
(Oshikanyama); oshikagadhi (Oshindonga); omule (Oshingandjera,
Oshikolonkadhi, Oshikwaluudhi); oshizenene (Oshimbalantu); plantluise
(Afrikaans) |
Pest status:
|
The pest status varies from season
to season. Aphids occur frequently on legumes such as Cowpea (Vigna
unguiculata) and Bambaranuts (Vigna subterranea). There
are no exact estimates of aphid damage but if the attacks start early in
the season, both crops will suffer badly. Outbreaks late in the season
do not seem to affect the crops. |
Description:
|
The stems and crown of bambaranut
plants are covered with black aphids. Young leaves curl up due to the sucking
of aphids. Flower formation is reduced. During severe attacks there is
often a circle of dead aphids and debris under each plant. |
Control:
|
Control is at present not recommended
in farmers' fields.
At the research station, the multiplication
fields have sometimes been sprayed to avoid loss of cultivars. The field
is first inspected to identify the major outbreak areas and only these
are sprayed.
During the rainy season it has been
observed that aphids were literally washed off the plants when there was
a heavy shower. If heavy rain is approaching, farmers are advised to wait
and see if this will clear the attack. |
Other notes:
|
Predators such as ladybirds and
hover flies usually turn up in large numbers when there has been an outbreak
of aphids on cowpea and bambara nut. This counter attack of beneficial
insects, however, is usually too late to protect the crop. |
