1. Identification, Symptoms and nature of damage: Minor pest
Leaf Webber
Slug caterpillar
Red ants

2. Identification, Symptoms and nature of damage of mango leaf webber
(Lepidoptera: Pyralida)

3. Mango Leaf Webber, Orthaga euadrusalis
Earlier, the leaf webber or “tent caterpillar”, Orthaga euadrusalis Walker was considered as one of the minor pests of mango
Since last five years it has become a major problem in North India, especially in old, crowded orchards where there is excessive shade.
Source:

4. Identification
Source:
ap_img/brinjal/br_lwdamage.jpg
Adult - Brown moth of medium size with wavy lines on fore wings.
Eggs - Eggs are laid in clusters of about ten, on buds and young leaves
Larva - Pale greenish with brown head and prothroacic shield. Fully grown caterpillar measures 2.5 to 3 cm. 
Pupa - Pupation takes place in silken cocoons

5. Symptoms
Leaflets, flowers and pods are held together to form a web by larvae
Larvae feed from inside these webs and give burnt appearance
Growth of the terminal shoot is impaired if infested
Infestations may begin as early as seedling stage and continue during flowering and podding
The infestation is severe in shady conditions.
Old orchards with lesser space between tree canopy have more infestation than open orchards. 

6. Nature of Damage
Its infestation starts from the month of April and goes up to December. 
Eggs are laid singly or in clusters within silken webbings on leaves. Upon hatching, the caterpillars feed on leaf surface by scrapping. 
Later, they make web of tender shoots and leaves together and feed within.
Generally, 1-9 larvae are found in a single web. 

7. Nature of Damage
Pupation takes place inside the webs in silken cocoons. 
The life-cycle takes 3-4 weeks
However, the last generation (December-January) pupates in the soil. 
The pupae diapause for about five to six months. 

8. Identification, Symptoms and nature of damage of Slug Caterpillar
Latoia lepida
(Lepidoptera: Limacodidae)

9. Identification
Caterpillar - fleshy and slug like, greenish body with white lines
Four rows of spiny tipped red or black which causes irritation and pain due to glandular secretion.
Adult - green wings with prominent dark patch at the base of each forewing
Source:

10. Symptoms of damage Feed gregariously on the leaves
Cause defoliation – leaving only the midrib and veins

11. Life Cycle of slug caterpillar
Moth lay eggs flat shining eggs in batches of on undersurface of leaves.
The caterpillars feed on leaves. The full grown larva is 2.5 mm approximately. Larva possesses spines which cause irritation and pain if touched.
Pupation takes place on stem in compact elliptical cocoon.

12. Identification, Symptoms and nature of damage of Red Ants
Nest of ants on
mango tree
Identification, Symptoms and nature of damage of Red Ants
(Hymenoptera :Formicidae)

13. Red Ant, Oecophylla smaragdina
Identification
The wingless ants or the workers measuring 1.2 cm long
Resembles house hold ants, but they are slightly longer
The workers are orangish red in colour
The male and female ants are greenish in colour

14. Life Cycle A colony of ants has
one queen
Number of soldiers
Two kinds of workers
Eggs, larvae and pupa housed separately
Eggs are covered with mucilage. Incubation period: 4-8 days
Three larval instars: days
Pupal Period: 5-7 days
Life cycle is completed in days
They store no food material except some coccids and aphids, whose honey-dew secretion the relish.
These are somewhat dynamic in that they may grow, or move when leaves die.

15. Nature of Damage/Control
The ants stitch together few leaves and build their nests in them on the trees
The ants do not cause any direct injury or loss to the tree.
Indirectly, the damage is caused by protecting aphids and scale insects from being preyed upon by their parasitoids and predators and also carries the nymphs of aphids, mealy bugs and scale insects from tree to tree thus spreading the infection of these noxious pests.
These ants aggressively defend "nests" and trees and, whilst they do not sting, chemicals in the saliva can irritate the skin.
They cause annoyance and make harvesting difficult.

16. Red Ant, Oecophylla smaragdina
As Bio-control agent
They also feed other insect pests and can be used in IPM for controlling other pests

17. Summary
Leaf webbers are active from Dec-April. Larvae webs the leaves and scrape the chlorophyll that results in drying and withering  of leaves. Pupation trakes place inside the web
Slug Caterpillar are fleshy and slug like, greenish body with rows of spiny tipped red or black hairs which causes irritation and pain due to glandular secretion. They Feed gregariously on the leaves, cause defoliation
Weaver ants/red ants stitch together few leaves and build their nests in them on the trees. They cause annoyance and make harvesting difficult.
Red ants also feed other insect pests and can be used in IPM for controlling other pests

18. Reference
Butani, D.K. (1993). Mango: Pest Problems. Delhi, India: Periodical Expert Book Agency, 290 pp.
Srivastava, R.P. (1997). Mango Insect Pest Management (first edition). Lucknow, India: International Book Distributing Co., 272 pp.