Blackgram, greengram, and cowpea are all leguminous crops that are vulnerable to similar pests. Some of the common pests affecting these crops include: Pod Borer (Helicoverpa armigera): The larvae of this moth species bore into the pods and feed on the developing seeds of blackgram, greengram, and cowpea, leading to yield losses. Aphids: Aphids can infest the leaves and stems of these crops, causing stunted growth, leaf curling, and the transmission of viral diseases. Whiteflies: Similar to aphids, whiteflies feed on the sap of the plants and can transmit viral diseases. They also excrete honeydew, promoting the growth of sooty mold. Thrips: Thrips are small insects that feed on the leaves and flowers of blackgram, greengram, and cowpea, causing damage and reducing plant vigor. Bean Fly (Ophiomyia spp.): The larvae of bean flies tunnel into the stems and pods of these crops, causing wilting, stem breakage, and reduced yield. Leafhoppers: Leafhoppers are sap-sucking insects that can transmit viral diseases to blackgram, greengram, and cowpea plants, leading to yield losses. Cutworms: Cutworm larvae can cut the stems of young plants at the soil level, leading to plant lodging and reduced stand establishment. Armyworms: Armyworm larvae feed on the leaves of these crops, leading to defoliation and reduced photosynthesis. Leaf Miner (Liriomyza spp.): The larvae of leaf miner flies tunnel into the leaves of blackgram, greengram, and cowpea, causing characteristic serpentine mines and reducing leaf area for photosynthesis. To manage these pests, integrated pest management (IPM) practices can be employed, including crop rotation, use of resistant varieties, conservation of natural enemies, and judicious use of pesticides when necessary. Early detection and monitoring of pest populations are also crucial for effective pest management in these crops.

1. Pests of Blackgram,
Greengram, Cowpea
By
Dr. U. Pirithiraj, P.hD.
Assistant Professor (Entomology)
JSACAT
Affiliated to Tamil Nadu Agricultural University

2. Sap feeders

3. Bean Aphid, Aphis craccivora, Aphididae, Hemiptera
1
Dr. U. Pirithiraj, P.hD. (Entomology)
Nature of damage
Colonies of nymphs and adults found on leaves, terminal
shoots and pods and such the plant sap
Vector of pea viruses - stunt disease in chickpea, rosette
of groundnut
Serious pest when the rainfall is low
Symptom of damage
The plants wither and vigour reduced
A. craccivora now is virtually worldwide

4. Thrips, Ayyaria chaetophora, Thripidae,
Thysanoptera
2
Dr. U. Pirithiraj, P.hD. (Entomology)
Nature of damage
Nymphs and adults suck the plant sap
Symptom of damage
Leaves mottled with characteristic silvering on
lablab, green gram, black gram and cowpea
Distribution. India and S.E. Asia to northern Australia, Japan, Taiwan and Tahiti.
Tiny yellow fringe winged adults

5. Whitefly, Bemisia tabaci, Aleyrodidae, Hemiptera
3
Dr. U. Pirithiraj, P.hD. (Entomology)
Symptom of damage
Yellowing of leaves, plant vitality reduced,
development of sooty mould, plant dies in
case of severe attack
Nature of damage
Nymphs and adults suck the plant sap and
also transmits yellow mosaic virus (YMV)
Worldwide distribution

6. Stalked, sub-elliptical,
light yellow at first, and
turning brown later on.
Eggs laid singly on
adaxial (lower) side of
leaves
Elliptical on emergence, soon they fix their
mouthparts into the plant tissues and feed on
the cell sap. Greenish yellow, oval on
undersurface of leaves
Small with yellow body covered with white waxy bloom
Dr. U. Pirithiraj, P.hD. (Entomology)

7. Green leafhopper, Empoasca kerri, Empoasca
binotata, Cicadellidae, Hemiptera
4
Dr. U. Pirithiraj, P.hD. (Entomology)
Nature of damage
Nymphs and adults suck the sap and inject
toxins.
Symptom of damage
Affected leaves turn pale and then rust-red.
They curl downwards; in severe cases, show
'hopper burn' symptom, dry and fall to the
ground.
Distribution: Rajasthan, Tamil Nadu, Uttar Pradesh, North America.

8. Yellow, laid on the underside of
the leaf, embedding them into
the leaf veins
Wedge-shaped, very active,
suck cell sap from underside
of the leaves
3 mm long, greenish
yellow during the
summer acquiring a
reddish tinge in the
winter. Adults move
briskly, forward and
laterally and jump or
fly away at slight
disturbance and
attracted to light at
night
Dr. U. Pirithiraj, P.hD. (Entomology)

9. Pod bug, Riptortus pedestris (Alydidae), Clavigrella
horrens, Clavigrella gibbosa, Coreidae, Hemiptera
5
Dr. U. Pirithiraj, P.hD. (Entomology)
Nature of damage
Nymphs and adults suck sap from pods
and also to stem, leaves and flower buds.
Symptom of damage
Pale-yellow patches in pods.
Shrivelled pods.
Important pest of soybean fields in Asian countries, including China, India, Japan, and South Korea

10. Freshly laid eggs are flat dorsally and round
in shape dull white brown in colour. Eggs
are laid in cluster of 3–15
Newly hatched nymphs are reddish in
colour and in the latter instars it
changes to brown
Dr. U. Pirithiraj, P.hD. (Entomology)

11. C. gibbosa: Greenish-brown
in colour, 2 cm in length,
with spines on either side of
the middle of the prothorax.
C. horrens: Robust, greyish
brown in colour with spines
at the anterior margin of the
prothorax.
R. pedestris: Slender elongated,
dark brown coloured bug with two
black bands on ventral side of the
abdomen.
Female has a round and swollen abdomen in comparison with a narrow and pointed
abdomen of the male. Dr. U. Pirithiraj, P.hD. (Entomology)

12. Leaf feeders

13. Leaf webber, Eucosma critica, Eucosmidae,
Lepidoptera
6
Dr. U. Pirithiraj, P.hD. (Entomology)
Nature/Symptom of damage
Vegetative stage - Caterpillar damages leaves by
webbing
Floral stage - Enter the buds, flowers and pods
and feed on the immature seeds.
Young larva - Concealed into the frass produced
during the course of scratching
Grown-up larva draws the two leaves together
and spins a thread between them
Widely distributed in India.

14. Leaf folder, Anticarsia irrotata, Noctuidae,
Lepidoptera
7
Dr. U. Pirithiraj, P.hD. (Entomology)
Nature of damage
Larva folds the leaf and remains inside the
fold and defoliates it
Symptom of damage
Leaves folded together
Yellowish brown moth with an
oblique black line on the wings
Green coloured
This moth was described from India. It is also recorded from Madagascar, Rapa, Society Islands,
and Samoa, indicating a wide range of distribution.

15. Subterranean pests

16. Termite, Odontotermes obesus, Termitidae, Isoptera
8
Dr. U. Pirithiraj, P.hD. (Entomology)
Nature of damage
They live underground, but make small earthen
mounds or earthen passages that are visible
above the ground.
Termites generally damage the crop soon after
germination and in subsequent growth stages.
Symptom of damage
The damaged plants dry up completely and are
easily pulled out.
Tropical and subtropical regions of India

17. Other pests

18. Redgram scale, Ceroplastodes cajani, Coccidae,
Hemiptera
9
Dr. U. Pirithiraj, P.hD. (Entomology)
Throughout India and eastern Africa
Nature/symptoms of damage
Though each insect takes only a few drops
of sap during its life time, presence of
enormous number of insects sucking the
sap continuously at times, weaken trees
and ultimately affect size of pods.

19. Redgram leaf roller, Caloptilia soyella, Gracillaridae,
Lepidoptera
10
Dr. U. Pirithiraj, P.hD. (Entomology)
Symptoms of damage
Mine the leaves of their host plant
Leaves folded together with tender shoots
showing bore holes
Cape Verde (Africa), China, Fiji, India, Indonesia, Japan,
Sri Lanka and Vietnam

20. Leaf eating caterpillar, Azazia rubricans, Noctuidae,
Lepidoptera
11
Dr. U. Pirithiraj, P.hD. (Entomology)
The larva causes
severe defoliation.
Adult moth
resembles a dry
leaf.
Distribution: Throughout India.

21. Sphingid caterpillar, Acherontia styx, Sphingidae,
Lepidoptera
12
Dr. U. Pirithiraj, P.hD. (Entomology)
North-central and western China westward across northern Thailand, Myanmar, Bangladesh, India, Sri Lanka,
Nepal, Pakistan and Iran to Saudi Arabia, Iraq, Jordan and Israel
Larvae feed voraciously on leaves and
defoliate the plants

22. Leaf cutter bee, Megachile antracena, Megachilidae,
Hymenoptera
13
Dr. U. Pirithiraj, P.hD. (Entomology)
Symptoms of damage
Cutting neat circular or oval patches from the
leaf margins.
Cut bits of leaves - used for the construction
nest cells.
They build cells in crevices and cavities in
hedges, dead wood etc.
Distribution in Kenya, Tanzania, Uganda, Eastern North America,
India - Lakshadweep, Maharashtra, Kerala, Tamil Nadu, West Bengal, Andhra Pradesh, Rajasthan