The document discusses 5 major orders of insect pests - Lepidoptera, Diptera, Hemiptera, Isoptera, and Coleoptera. For each order, it provides details on morphological features, mouthparts, life cycles, examples of pests, and economic significance. The document is intended as an assignment for students to comment on the characteristic features of each order with supporting diagrams.

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Dr. A. S. Wabale
Assistant Professor and Research Guide
Post Graduate Department of Botany and Research Centre,
Padmashri Vikhe Patil College of Arts, Science and Commerce, Pravaranagar- 413 713
dranilwabale78@gmail.com
ORDERS OF INSECT PEST

2. June 27, 2020
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Chapter-1: Orders of Insect Pests
1) Lepidoptera
2) Diptera
3) Hemiptera
4) Isoptera
5) Coleoptera
Dr. A. S. Wabale

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June 27, 2020
Dr. A. S. Wabale
Order: Lepidoptera
ü The word Lepidoptera comes from Ancient Greek (lepís “scale” + pterón “wing”)
ü It is an order of insects that includes butterflies and moths
ü About 180,000 species of the Lepidoptera are described in 126 families and 46 superfamilies,10 %
of the total described species of living organisms
ü The most noticeable is the presence of scales that cover the body, wings and proboscis. The scales
are modified, flattened "hairs", and give butterflies and moths their wide variety of colors
and patterns.
ü Two pairs of membranous wings covered with tiny scales which give colour, rigidity & strength
ü Bright colored
ü Knob or club like antennae
ü Siphoning type of mouth parts
ü Large Compound eyes with many light sensitive lens
ü Complete metamorphosis i.e. Egg, Larvae, Pupae and Adult
ü Larvae with mandibulate type of mouth parts
ü Larvae bears 3 pairs of thoracic legs and many prolegs on abdomen

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Types of Mouth Parts in Insects
CHEWING and BITTING TYPE
PIERCING AND SUCKING
TYPE
SPONGE TYPE SIPHONING TYPE
June 27, 2020
Dr. A. S. Wabale

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Significance
Butterflies and moths play an important role in the natural ecosystem as pollinators and as food in the food chain;
conversely, their larvae are considered very problematic to vegetation in agriculture, as their main source of food
is often live plant matter.
Moth Butterfly
Yellowish white in colour Bright colored
Nocturnal Diurnal
Mostly two ocelli present Ocelli absent
Wings at rest held in horizontal position Wings at rest held in Vertical position
Pupae covered with cocoon Pupae are naked known as chrysalis
Larvae covered with hairs Larvae are smooth and naked
June 27, 2020
Dr. A. S. Wabale
Order: Lepidoptera

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Dr. A. S. Wabale
In many species, the female may produce from 200 to 600 eggs, while in others, the number may
approach 30,000 eggs in one day.
Metamorphosis in Lepidoptera
Eggs
Larvae
Cocoon
Adult

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June 27, 2020
Dr. A. S. Wabale
Order: Diptera
This is one of the largest insect orders including many known insects such as mosquitoes and house
flies. The word diptera means insects bearing two wings
ü One pair of wings (forewings)
ü Hind wings are reduced to club-like halters. The halters are used for stability during flight
ü A large and moveable head
ü Compound eyes that are often very large on a mobile head
ü Sucking, piercing and sucking or sponge-like mouthparts (all adapted for a liquid diet)
ü The legs of insects are appendages consisting of three pairs, one for each thoracic segment. The
forelegs are called also prothoracic, the midlegs mesothoracic, and the
hindlegs metathoracic.
ü It displays a complete metamorphosis (egg, larva, pupa, adult)
ü The larvae are legless, and have head capsules with mandibulate mouthparts in the Nematocera.
ü The larvae of "higher flies" (Brachycera) are however headless and wormlike, and display only three
instars.
ü Pupae are obtect (enclosed in a firm case or covering with the appendages held tightly against the
body) in the Nematocera, or coarcate (a pupa closely covered by the old larval skin) in
Brachycera.
ü Many species of Diptera are vectors of diseases. E.g. as mosquitoes are considered to spread malaria
Obtect Pupa Coarcate Pupa

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Dr. A. S. Wabale
Order: Diptera
PIERCING AND SUCKING
TYPE
SPONGE TYPE HALTERS

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June 27, 2020
Dr. A. S. Wabale
Order: Hemiptera
Hemiptera means "half-wings", referring to how the wings overlap and how they are made of two
dissimilar halves.
Commonly known as True Bugs, is a large and varied order. There are 80,000 described species
belonging to 37 families.
Hemiptera are also important in agriculture, known to cause direct damage to plants by herbivory and
indirectly by transporting diseases (Dooling, 1991).
• Basal portion of the front wing is thickened and leathery
• Apical portion is membranous (this type of wing is called hemelytron, or hemelytron if single)
• Hind wings are completely membranous and shorter than the front wings
• Wings at rest are held over the abdomen with membranous tips overlapping
• Some are wingless
• Piercing-sucking mouth parts
• Mouth part in form of segmented beak arising from front part of the head and extending back along
the ventral side of the body
• Antennae are fairly long and contain four to five segments

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• Compound eyes are usually well developed
• Many have glands secreting unpleasant odor
• Eggs cases may be laid on plants or sometimes just dropped
• Simple metamorphosis with mostly five nymphal instars
• Most species are terrestrial but some are aquatic
• Predacious ones are beneficial to man
• Some may serve as disease vectors
• Some insects like Aphids show both
Parthenogenesis is a natural form of asexual reproduction in which growth and
development of embryos occur without fertilization by sperm. In animals, parthenogenesis means
development of an embryo from an unfertilized egg cell. In plants parthenogenesis is a component
process of apomixis.
Among animals, viviparity is development of the embryo inside the body of the parent,
eventually leading to live birth. This is opposed to oviparity which is a reproductive mode in which
females lay developing eggs that complete their development and hatch externally from the mother.
Dr. A. S. Wabale
Order: Hemiptera

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Fore Wings
Hind Wings
Piercing and
Sucking Type
Mouth Part
Dr. A. S. Wabale
Order: Hemiptera

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June 27, 2020
Dr. A. S. Wabale
Order: Hemiptera- Examples
Source: Encyclopedia Britannica

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Dr. A. S. Wabale
Order: Hemiptera- Life Cycle
Source: Dreamstime.com

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Dr. A. S. Wabale
Order: Isoptera
• The word Isoptera is derived from the Greek word “iso” meaning equal and “ptera” meaning wings.
It refers to the similar size, shape and venation of the four wings.
Immature (Soldiers and Workers)
• Body pale in color, somewhat ant-like in appearance but with a broader junction between thorax and
abdomen. Workers are cream-colored
• Compound eyes small or absent
• Head large and cylindrical or small and round
• Antennae beaded
• Mouthparts chewing; sometimes with large mandibles
Adults (reproductive)
• Body may be darkly pigmented
• Head well-developed, with chewing mouthparts and beaded antennae
• Compound eyes present
• Two pairs of membranous wings, all similar in shape and size; wings are shed after mating
Termites are an important part of the community of decomposers. They help to break down
and recycle up to one third of the annual production of dead wood. Termites are economic pests for
human homes, building materials, forests, and other commercial products.

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Nymph
Larvae
Eggs
King Termite
Queen Termite
De-alate
Alate
Reproductive
Soldier
Worker
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Metamorphosis in order: Isoptera
Dr. A. S. Wabale

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The name Coleoptera, derived from the Greek words "koleos" meaning sheath and "ptera" meaning wings. It refers
to the modified front wings which serve as protective covers for the membranous hind wings. Coleoptera is the
largest order in the animal kingdom. It includes 40% of all insects and nearly 30% of all animal species.
Immatures:
• Head is well-developed with ocelli and chewing type of mouthparts.
• Three pairs of thoracic legs
• No abdominal prolegs
Adults:
• Complete development (egg, larva, pupa, adult)
• Chewing mouthparts (sometimes located at the tip of a beak or snout)
• Tarsi (leg part) 2 to 5-segmented
• Hind wings large, membranous, folded beneath the elytra
• Front wings (elytra) are hard and serve as covers for the hind wings; meet in a line down the middle of the back
Many beetles are regarded as major pests of agricultural plants and stored products. They attack all parts of living
plants as well as processed fibers, grains, and wood products.
Scavengers and wood boring beetles are useful as decomposers and recyclers of organic nutrients.
Predatory species, such as lady beetles, are important biological control agents of aphids and scale insects.
Order: Coleoptera
June 27, 2020
Dr. A. S. Wabale

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Metamorphosis of Order: Coleoptera
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Dr. A. S. Wabale
Adult
Egg
Pupa
Larvae

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Assignment
June 27, 2020
Dr. A. S. Wabale
1. Comment of the characteristic features of Order Lepidoptera with suitable diagrams
2. Comment of the characteristic features of Order Diptera with suitable diagrams
3. Comment of the characteristic features of Order Hemiptera with suitable diagrams
4. Comment of the characteristic features of Order Isoptera with suitable diagrams
5. Comment of the characteristic features of Order Coleoptera with suitable diagrams