Pests of leafy vegetables

1. PESTS OF LEAFY VEGETABLES

2. 1. Amaranthus stem weevil,
Hypolixus truncatulus
(Curculionidae: Coleoptera)
Distribution: India and neighboring countries
Host range: Amaranthus (both wild and cultivated)

3. Damage symptoms
1. Grubs bite into stems, feed on pith region
making irregular zigzag tunnels and fill with
excreta.
2. Stems split longitudinally.
3. Plants dry completely.
4. Adult feeds on tender leaves, makes circular
holes in stems, branches and mid-ribs.
5. Attack causes stunting of plants, twisting and
swelling of branches and stem and suppression
of shoot and leaf production.

4. Damage Symptoms

5. Bionomics - 1
1. Females lay eggs singly in each hole and cover
holes with secretion.
2. A female lays 30-34 smooth, oval and pale yellow
eggs, egg period 4 to 10 days.
3. A single stem contains 17-20 grubs in it.
4. Grubs are stout, curved, apodous and white in
colour.
5. Grub stage lasts for 12 - 24 days.
6. Full-fed grubs form a greyish-brown hard
compact gall like chamber and pupate therein.

6. Bionomics - 2
1. On emergence, they remain inside the stem for 5
to 6 days, then cut epidermal membrane and
emerge out.
2. Adults are ash-grey in colour, with elbowed
antennae and brown elytra.

7. Management
1. Destroy all wild amaranthus plants in the
vicinity.
2. As soon as infestation is observed, remove and
destroy promptly all the affected plants with
grubs inside.
3. Spray chlorpyriphos or quinalphos @ 2ml/L.

8. 2. Amaranthus caterpillar or webber
Hymenia recurvalis
(Crambidae: Lepidoptera)
Distribution and status : Destructive pest. Widely
distributed in tropical and subtropical regions
including Africa, Asia and Australia. In the Indian
sub-continent it is found all the year round, but is
more active during warmer, rainy and early winter
months.
Host range
Amaranthus, beans, melons, spinach, coleus, Luffa
spp., grasslands and pastures

9. Damage symptoms
Larvae scrape the epidermal and palisade tissues
of leaves; web the leaves with silken threads
resulting in drying of webbed leaves.

10. Identification
1. Eggs are spherical in shape and snow white in
colour.
2. Caterpillars are greenish in colour with white
lines.
3. Full grown larva measures 17-20 mm in length.
4. Pupae are 10-14 mm long and brownish in colour.
5. Adults are black coloured.
6. Both pairs of wings are dark fuscous in colour,
outer margins are fringed with short hairs.
7. Wing expanse is 15-20 mm.

11. Life cycle
•Eggs hatch in about 3-4 days
• Larval period is 12-16 days
•Pupal period lasts for 8-12 days
•Total life cycle is completed in 3-4 weeks.
Salient features
• Each female lays 50-80 eggs singly or in batches of
2-5 usually on grooves of leaf veins
•Larvae feed on leaves
• Pupate in soil

12. Management:
1. Collect and destroy wild amaranthus hosts in
the vicinity of cultivated crop.
2. Collect and destroy affected plant parts along
with larvae and adults.
3. Emergency spray of indoxacarb @ 0.6 to 0.7ml/L
or flubendiamide @ 0.2 to 0.5ml/L or coragen
@ 0.3ml/L or quinalphos/chlorpyriphos @
2ml/L or lambda-cyhalothrin @ 1ml/L etc.

13. 3. Leaf caterpillar
Eretmocera impactella
(Scythrididae : Lepidoptera)
Distribution: Distributed in the Indian subcontinent
Hosts: It is a sporadic pest of amaranthus and
spinach
Damage
Caterpillars web the leaves and feed inside

14. Leaf caterpillar, Eretmocera impactella
(Scythrididae : Lepidoptera)

15. Bionomics
1. Eggs are laid on leaves or on top shoots.
2. Full-grown caterpillars are cylindrical,
brownish-yellow to brownish-grey in colour
with a broad sub median dark stripe and black
tubercles bearing several divergent longitudinal
hairs.
3. Long brown pupae in white silken cocoons
remain attached to leaves.
4. Moths are small, blackish with prominent
yellow spots on fore wings.
5. Life cycle is completed in 3 to 4 weeks.

16. Management:
1. Collect and destroy wild amaranthus hosts in
the vicinity of cultivated crop.
2. Collect and destroy affected plant parts along
with larvae and adults.
3. Emergency spray of indoxacarb @ 0.6 to 0.7ml/L
or flubendiamide @ 0.2 to 0.5ml/L or coragen
@ 0.3ml/L or quinalphos/chlorpyriphos @
2ml/L or lambda-cyhalothrin @ 1ml/L etc.

17. 4. Aphids, (Aphididae: Hemiptera)
• Ground nut aphid, Aphis craccivora
• Mustard aphid, Lipaphis erysimi
• Green peach aphid, Myzus persicae
5. Mealy bugs: Ferrisia virgata
(Pseudococcidae: Hemiptera)
Suck vital sap from leaves.

18. 6. Thrips
• Euryaplothrips crassus
• Haplothrips ceylonicus
(Thripidae: Thysanoptera)
Scrap the leaf tissues then suck vital sap from
leaves.

19. 7. Spinach blue beetle
Altica caerulescens
(Chrysomelidae: Coleoptera)
Hosts: Spinach, cabbage, strawberry and plums
Damage
1. Freshly emerged grubs scrap and feed on
chlorophyll containing tissues.
2. Later grubs mine inside the leaves and feed on
the mesophyll tissue.
3. Adults nibble the leaf margins causing very
little damage.

20. Identification
1. Grubs are 5-10 mm long, dark brown in colour.
2. Pupae are 12-15 mm long and brown in colour
when freshly formed and turns blackish brown
later on.
3. Adults are 5-7 mm long steel blue in colour

21. Management
1. After the crop is over, plough the field deep to
kill the grubs present in the soil.
2. Collection and destruction of adult beetles
reduces the population.
3. Spray chlorpyriphos or quinalphos @ 2ml/L.
4. Observe a waiting period of about 10 days.

22. THANK YOU