Detailed description of pest of Sweet potato and their management

1. Pests Of SWEET
POTATO And Their
Management

2. 1.SWEET POTATO WEEVIL
S.N. - Cylas formicarius
Family - Apionidae
Order - Coleoptera

3. Economical importance
 Serious pest of sweet potato .
Damage percentage - 60- 70%
Host plant
 Specific to Sweet potato

4. Mark of Identification
Grub
The grub is pale yellow in color and legless.
Adult
 It is a wingless, ant–like steel black weevil with a
brown elongated snout and thorax.

5. Sweet
Potato
Weevil

6. Life history
 Eggs - on the tuber & stem of vines by making
small cavities .
 Larva - L . P
. – 2 -3 weeks
 Pupa - Pupation in larval burrows in vines.
P
.P - 7days.
 Life cycle completed - 4-5 weeks
 No of generation - 8-9 / year.

7. Nature of damage
 Grub bore into vines ( stem )& causes tunneling inside and feed
on soft tissues .
 Grub and adults bore into tubers both field and godowns , feed
on inner content & spoil them .
 Affected tuber develop dark patches ,which is latter start rotting
.
 Pest is carried out one field to another through the infested
vines & from season to season by breeding in tuber left over
after harvest .

8. Larval feeding
Larva

9. Sweet potato weevil - tuber develop dark patches

10. Management
 Healthy cuttings should be selected for planting
 After harvest of the crop ,vines should be collected and
destroyed .
 Follow proper crop rotation .
 Mulching with leaves chromolaena doormats at 3 tones/ ha
30 days after planting
 Ear thing up at 50 days after planting

11. Install yellow sticky trap @ 12/ha
Spray quinolphos 25 EC 1.5 lit in 750 lit of water .
Dip planting materials in monocrotophos 36 WSC 15
ml /lit of water.
In godowns treat with malathion 5% OR carbaryl %
dust
Fungi – Beveria basssiana ,Metarizium anisopliae

12. 2. Sweet potato leaf eating caterpillar / Sweet potato
hornworm,/ Convolvulus hawk moth/ Sphinx
caterpillar
S.N. - Agrius convolvuli
Family - Sphingidae
Order - Lepidoptera

13. Sweet potato leaf eating caterpillar

14. Economical importance
Important pest ,It causes economic losses
Host plant
Potato , sweet potato ,Green gram, Black gram

15. Mark of Identification
Adult
 Pale gray colored with black pointed head
Caterpillar
Dark brown with radish patches on sides &
sharp curved horn at tail end

16. Life history
Eggs - Seed like laid singly on leaves.
Larva - L.P
. - 2-3 Weeks
Pupa - in soil
Life cycle completed - 4-15 weeks.
S.O. - Pest active in monsoon
Pest hibernate in pupal stage .

17. caterpillar
Adult Pupa

18. Nature Of Damage
The caterpillar feeds on leaves
voraciously
In case of severe infestation
defoliate the plant.

19. Control Measures
 Collection and destruction of caterpillar
Ploughing the field after harvest to expose the
pupa
Dusting with 10 % carbaryl.