The document summarizes the life cycles of various insect pests that affect important forest trees in India. It provides details on the egg-laying, hatching, larval, pupal, and adult stages of different insects that are pests of trees like teak, sal, chir pine, deodar cedar, sissoo, bamboo, silk cotton, and others. For each insect pest, it mentions the number of generations per year, duration of different stages, overwintering behavior, number of eggs laid, and other key life cycle details. The life cycles described range from 14-41 days for some insects to over 1 year for beetle grubs that feed on deodar cedar

1. Life cycles of insect pests of important
forest trees
By
CH. BHARGAVI
M.Sc Forestry
IGKV, Raipur

2. INDEX
• Tectona grandis
• Shorea robusta
• Pinus roxbhurghii
• Cedrus deodera
• Dalbergia sissoo
• Bamboo
• Bombax ceiba
• Anthocephalus cadamba
• Ailanthus excelsa
• Acacia nilotica
• Murayya
• karanj

3. Tectona grandis
Hyblea purea:
 The life-cycle (from egg to emergence of the moth) completes in 15-34 days and there are about 14 generations of
the pest in a year depending on the climatic conditions and the quality of the available food.
 The average number of eggs laid by one female is between 500-600 but the maximum number of the eggs
sometimes may exceed over 1000.
 The incubation period varies from 2 to 4 days.
 The newly hatched larva protects themselves with silk strands during feeding and at the new shelter of the feeding
place is changed.
 The young instars feed by scrapping the epidermis in small patches.
 The later larval instars (stages) from small semi-circular incisions in the leaves.
 The larval period varies from 8-10 days.

4.  Molting takes place in the leaf folds where it stops feeding and looses its body
color. 1 or 2 hours is needed after the old skin is cast for hardening and
pigmentation of the new body and several more hours are spent resting before
feeding is resumed.
 Pupation takes place in the folded leaves by silken threads and in case of
complete defoliation, the larva drops by a thread to pupate in the fallen leaves in
the soil.
• Pupal period various from 5 to 13 days

5. Larva and adult

6. Hapalis macharalis
 The maximum number of eggs produced buy one female is 550.
 Eggs are laid singly on both sides of the leaves and hatch in 3days or more.
 The young larvae feed on the superficial cells of the epidermis of the leaf under the
protection of strands of silk spun in an escape hole and skeletonize the whole leaf.
 Molting takes place on green leaves or on undergrowth or in fallen dead leaves by
spinning a thick shelter web. Life cycle takes completes in 14-41 days and 14-15
generations in a year

7.  Larvae hibernate during winter and pass 5-6 months in web among dried leaves.
 The larval period is 8-27 days.
 Pupal period varies from 4-11 days.
 The life cycle from egg to emergence of the moths varies from 14-41 days.
 There are 14-15 generations in a year

8. Adult Larva

9. Hypsiphyla robusta
 Female lays 400-600 eggs.
Larvae feed on all parts .
 Life cycle lasts for 24-29
days.(egg 4- 5, larval 1
days pupa 8-12 days.
Moth appears in the month of
March
Larva
Adult

10. Shorea robusta
Hoplocyrambyx spinicornis
One female lays 100 to 300 eggs.
The incubation period is 3-7 days. 1 to 2 generations in a year
The grubs (larvae) after hatching from the eggs establish tunnel in the bark, than
in sapwood and finally into the heartwood of the sal trees.
The larval period is 2-3 weeks.
Pupation takes place in a cell and the pupal period is 2-3 weeks.
The insert turns into a beetle in May-June and waits until the monsoon arrives

12. Pinus roxburghii
Platypus biformis
As many as 20 or 30 eggs are laid by a female beetle and from them hatch out
minutes white dots, the size of pin’s head, which ultimately grow into small,
elongates larvae with yellowish heads.
The length of each larva is about 1/4th inch.
The length of the life cycle (from egg to beetle) is variable seasonally but is
about 6-8 weeks as it’s shortest. Few days Page 26 2 or 3 generations in a year
Eggs lay in the 1st to 2nd week of October hatch out within a couple of days
or so, and the larvae are full-grown by the end of the month or first week in
November.

13. The Pupal stage is about 2 weeks, and the mature beetles issue about the 3rd
week of November if the weather is favorable.
Emergence of the over wintered generation begins in April and May according
elevation of Aspects of the pine forests, or as early as March at an elevation of
2200 feet.
Larva

14. Coniferous bark beetle
 In each gallery 30-60 eggs are laid by a female
beetle.
 The larvae on hatching eat their galleries in bast.
 The large, squarish pupal cell is opened out in the
bark at the end of the larval gallery.
 The maturing beetles bores from the pupal cell
through the bark in order to escape.
 In a crowded attack practically all the available
surface and depth is occupied and converted to
dust.

15. Cedrus deodera
Melolontha sps
 The eggs hatch in 2 to 3 weeks.
 The larva is a large (2” long), white grub of the eruciform type (the form of a ‘C’).
 The larval life is for more than one year.
 The grub cuts through the roots of seedlings and young plants, or often gnaws away the bark all round.
 Pupal stage is short but the beetle spends long time in the soil in resting stage to become chitinous parts
solidified.
 Immature beetles in the soil are light yellow, yellow brown in color.
 In the subtropical plains, the life cycle is normally annual with a larval period of 8 to 10 months. In the
mountain above 6000 ft. the life cycle lasts 2 years.

16. Larva Adult

17. Dalbergia sisso
Sissoo leaf roller
 A small cavity is bitten in the midrib and an egg inserted.
 The roll remains suspended from the petiole for a while or falls at once.
 The egg hatches in 3 to 6 days during March-September and in 6 to 8 days in October.
 One female may lay 20 eggs.
 The larva feeds on the inner rolls leaving the outer sheath untouched.
 The larval period is 10 to 16 days during March to April, 4-7 days during May-October
and 20-30 days in November, December

18.  The pupal stage lasts 3 to 6 days during March-October and 5 to 9 days in
November, December. 18. There are about eight generations in a year.
 The first-generation beetle emerges in March from rolls formed in October. 20.
However, the beetles emerging in December do not survive in the winter.
Larva

19. Acmaeodera Kerremansi
Female lays eggs singly or in a small cluster of 3-6 on
the bark of the dead or dying bast or crevices of the
trees.
The size of the larva is about 11mm long.
The larval life may last for a few weeks only, or may
extend to nearly a year.
The mature larva pupates inside the sapwood in a short
vertical pupal chamber.
The pupa spends a few weeks only in this stage of its
existence
The life cycle is normally annual.

20. Bamboo
Dinoderus minutus
 From these eggs small white roundish dots of grubs issue within a few days of their being
deposited.
 The grubs are opaque, curved with the swollen thoracic segments.
 Length is 3mm to 3.75mm.
 About four weeks are spent in this stage, and the grubs then enlarge the ends of their burrows and
change to pupae, which after some eight days or so, turn into the beetles.
 On becoming mature the beetles bore their way out of the bamboos, and thus add further to the
tunnels already made in them.
 On emergence the insects fly off to attack fresh bamboos, or they may bore into the one in which
they have themselves matured.

21.  In the warmer parts of the country it passes through at least five and
perhaps more, generations or life-cycles in the year.
 The first generation takes about 7 weeks (April-June); the second
about 4-5 weeks (June-July); the third about 4 weeks (July-
September); the fourth about less than 4 weeks (September); the
fifth from the end of September to the end of October.
 It is probable that many of the beetles of the fifth generation were
caught and killed off by the cold snap experienced towards the end
of the moth. Few days 4 weeks 3days

22. Anthocephalus cadambae
Lymantria matura:
 Eggs with almost completely developed larvae overwinter under bark scales. Neonate
caterpillars usually appear in the first half of May and continue to hatch for around 20
days.
 For the first 4–5 days, they neither spread nor feed. The feeding period covers May, June
and July. Caterpillars feed first on buds, then on leaves, preferring to stay on leaves and
not on branches.
 The most active feeding is observed in the evening. During outbreaks, the pest
population level may reach more than 1000 caterpillars per tree.

23.  Pupation of L. mathura occurs on leaves
and branches in crumbly cocoons or
almost without cocoons in July, usually 5–
7 days later than pupation of L. dispar.
 Pupal development lasts 12–18 days.
Flights occur at the end of July and in
August. Males and females are strong
fliers, active at night and attracted to
lights.
Larva
Adult

24. Ailanthus excelsa
Atteva fabricella
 Small pale green eggs are laid either as single or small groups, usually on young buds
and tender leaves.
 Incubation lasts from 2–3 days according to the season, and emerge 1st instar larva.
 There are five larval instars, where the larval period may be 13–20 days.
 Fifth matured larva constructs a loose cocoon and pupates.
 Color of the pupa changes from orange brown to pale yellow brown.
 The pupal stage completes after 4–14 days.[

25. Eligma narcissus
 Moth large, grey, black and yellow; egg pale white, larva bright sulphur yellow
with black and red patches, pupa dark brown.
 Moth oviposits in clusters, incubation period 3-4 days, larval period 22-23 days
and pupal period 15-17 days. There are 8-9 generations a year.
Adult
Larva

26. Murayya
Papilio polytes
The eggs are laid singly on top of the
leaves. They are round and yellow to light-
orange in colour.
Common Mormon caterpillars are
heavily parasitized by chalcid wasps, with
over a hundred tiny wasps eventually
emerging from each Mormon pupa
The pupa is located on underside of
leaves and twigs. The pupa is light green
and unmarked. It has two projections to the
front on its head and also one on its thorax.
egg
instars

27. pupa
Pre pupa
5th instar

28. karanj
Glyphodes negatalis
Female insect lays eggs on upper surface of leaves. A female can lay an average of
160 eggs
Larva of the insect observed to moulted four times and thus passes through the
five larval instars in 18 to 23 days.
Pupae are formed in rolled leaf. The newly formed pupa was pale greenish brown
in colour but the colour soon changed to reddish brown and finally to dark brown
before adult emergence.
The fully grown larva of fifth instar became sluggish and suspended feeding and
movement. The length of pre pupa varies from 9.84 to 12.84 mm.
Male adult moth has a wingspan of 18 to 22.8 mm with an average of 20.49.
where female was with 20.5 to 25.02 mm.

29. Larva
Adult

30. Reference
 Studies on the Biology, Ecology, Life History, and Parasite Complex of Ailanthus Defoliator Eligma
narcissus Cramer (Noctuidae : Lepidoptera), together with Morphology of Adult and Immature Stages
 P. N. Chatterjee , Pratap Singh , R. M. Misra
 Sohn JC, Wu CS (2013). "A taxonomic review of Attevidae (Lepidoptera: Yponomeutoidea) from China with
descriptions of two new species and a revised identity of the Ailanthus webworm moth, Atteva fabriciella,
from the Asian tropics". J Insect Sci. 13 (66): 1–16.
 (Blackwell Publishing, Ltd. European and Mediterranean Plant Protection Organization Organisation
Européenne et Méditerranéenne pour la Protection desPlantes)
 Forest protection book.
 www.wikipedia.org/wiki/papilio polytes
 6) www.researchgate/glycophodes.