Pigeonpea and Chickpea Insect Identification Handbook - Agropedia

Pests of Foliage and Pods
A p h i d s Aphis craccivora ( K o c h )
Acyrthosiphon pisum ( H a r r i s )
( H e m i p t e r a : A p h i d i d a e )
D i s t r i b u t i o n . Both these species are w i d e l y d i stributed
and f o u n d on a wide range of l e g u m e s in all regions where
chickpeas are cultivated.
S y m p t o m s . T h e aphids feed on stems, leaflets (Fig. 96),
and pods (Fig. 97). T h e plants wilt w h e n large colonies
build up on t h e m . However, stunt disease causes the most
damage in c h i c k p e a (Fig. 98). This is caused by bean
leaf-roll virus w h i c h is transmitted by these aphids. Stunt
disease limits plant g r o w t h , and leaflets are small and
reddish b r o w n (yellow in kabuli types). S c r a p i n g the lower
part of the stem reveals b r o w n phloem w h i c h is characteristic
of this disease.
D e s c r i p t i o n a n d b i o l o g y . Aphis craccivora (1.6 mm
long) is a black shiny a p h i d while A. pisum (2 mm long) is
grey-green. Winged p a r t h e n o g e n e t i c females are carried
by the w i n d . Many that land on c h i c k p e a m a y be deterred
and fly off or be killed by the acid exudate. Plants w i t h
colonies have little or no exudate. It is not k n o w n whether
this is because the aphids feed on the exudate or whether
colonies develop on plants that p r o d u c e little exudate. T h e
n y m p h s resemble the adults and one g e n e r a t i o n can be
completed in less than 2 weeks.
C o n t r o l . A p h i d s are seldom n u m e r o u s e n o u g h on chickpea
to merit c o n t rol measures but stunt disease causes
substantial losses in s o m e years in some areas. Several
chickpea genotypes are k n o w n to be resistant to this disease
so the best means of c o m b a t i n g it is by the use of
resistant cultivars.
Figure 96. Aphis craccivora on leaves.
Figure 97. A. craccivora on pods.
Figure 98. Symptoms of stunt disease.
94