Transcript RLO- Mango minor pests

Identification, Symptoms and nature of
damage: Minor pest
Leaf Webber
Slug caterpillar
Red ants
Identification, Symptoms
and nature of damage of
mango leaf webber
(Lepidoptera: Pyralida)
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:http://www.plantwise.org
Identification
Source: http://www.ikisan.com/Crop%20Specific/
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
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.
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.
Nature of Damage
Pupation takes place inside the webs in
silken cocoons.
The life-cycle takes 3-4 weeks
However, the last generation (DecemberJanuary) pupates in the soil.
The pupae diapause for about five to six
months.
Identification, Symptoms
and nature of damage of
Slug Caterpillar
Latoia lepida
(Lepidoptera: Limacodidae)
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: http://www.rakbankerd.com/kaset/Plant/2958_1.jpg
Symptoms of damage
Feed gregariously on the leaves
Cause defoliation – leaving only the midrib
and veins
Life Cycle of slug caterpillar
Moth lay eggs flat shining eggs in batches of
20-30 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.
Nest of ants
on
mango tree
Identification, Symptoms
and nature of damage of
Red Ants
(Hymenoptera :Formicidae)
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
Life Cycle
A colony of ants has
– one queen
– Number of soldiers
– Two kinds of workers
http://www.myrmecos.net/formicinae
Eggs, larvae and pupa housed separately
–
–
–
–
Eggs are covered with mucilage. Incubation period: 4-8 days
Three larval instars: 10-17 days
Pupal Period: 5-7 days
Life cycle is completed in 20-30 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.
•
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.
Red Ant, Oecophylla smaragdina
As Bio-control agent
They also feed other insect pests
and can be used in IPM for
controlling other pests
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
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.
http://www.rakbankerd.com/kaset/Plant/2958_1.jpg
http://www.thaibugs.com/wpcontent/gallery/ants/Oecophylla%
20smaragdina1.jpg