The document provides information on the orders Grylloblattodea, Trichoptera, and Thysanoptera. Grylloblattodea, or ice crawlers, are small, soft-bodied insects found in northern regions. They live under rocks near snow and emerge at night to feed. Trichoptera, or caddisflies, are aquatic insects found in rivers and streams. They have membranous wings and undergo complete metamorphosis. Thysanoptera, or thrips, are tiny insects with four fringed wings. They pierce plant or animal tissues to feed and can be pests of crops.

1. Presentation on
Characteristics of different insect order
Presented by
Bipin Karki
ENT-07M-2019
AFU,Rampur,Chitwan

2. Grylloblattodea
• This is suborder of order Notoptera. This includes small sized insects i.e. rock
crawlers, ice crawlers or ice bugs.
• The Grylloblattodea or ice crawlers, are a small group of soft-bodied, apterous,
terrestrial and termite-like insects confined to the Northern Hemisphere.
Characteristics
• Cryptic, ground-dwelling insects that prefer wet habitats and cool temperatures.
• Slender and depressed insects covered with fine hairs and having reduced eyes.
• Live under rocks under or near snowbanks emerge after dark.
• Feed scavengers or predators on dead or dying insects that have been blown
onto the snow from lower elevations.

3. • Heads are projected, antennae are elongated and thin, eye comprises fewer
ommatidia in young instars than in adults, ocelli are absent, and legs are
simple, slender and not suited for jumping. The abdomen has 11 segments
with long and flexible cerci and asymmetrical male genitalia. The
ovipositor has three pairs of slender, tapering, partly free valves.
• Normally considered to be cold-adapted insects, they cannot withstand
temperatures much below 0°C. At -5.5 to 8.0°C, they become stressed.
• It has ony one family i.e. Grylloblattidae.

4. Trichoptera
• This order falls under superorder Endopterygota.
• Trichoptera or caddisflies are an order of aquatic insects occurring around
the world in rivers, streams, and lakes.
• Almost all caddisflies live in a case or retreat with the exception of
Rhyacophilidae.
Characteristics
• Most insect species of this order are found in cool, lotic waters and are
nocturnal.
• Most species hold their wings along their bodies when at rest which are
membranous and covered with short hairs.
• Wings are 2 paired having hind wing shorter than forewing. Antenna are
long, many segmented and pointed forward.

5. • They have sclerotized head, sclerotized plate on thoracic segment one (and
sometimes also on 2 or 3 segments), soft abdomen, 3 pairs of segmented legs and
an abdomen that terminates in a pro-legs bearing hooks.
• The adults of most species have reduced mouthparts and feed is restricted to
sucking nectar and other plant juices.
• Metamorphosis is holometabolous type.
• The eggs are normally laid in or near water in a jelly like substance except except
Limnephilidae family. Limnephilidae deposit egg masses above the water on
plants or stones.
• Larvae may be herbivorous, carnivorous or omnivorous.
• Those species which construct a larval case, usually pupate in the case which has
been attached to a support. Free living larva construct a shelter for pupation.
• The pupa possesses a strong pair of mandibles to bite its way out of the shelter
and rise to the water surface and use a pair of modified legs to reach land.

6. Some families
• Brachycentridae (humpless case maker caddisflies)
•Glossosomatidae(saddle case maker caddisflies)
•Helicopsychidae (snail case maker caddisflies)
•Hydropsychidae (common net spinner caddisflies)
•Hydroptilidae(micro caddisflies)
•Lepidostomatidae(Lepidostomatid case maker
caddisflies)
•Limnephilidae(Northern case maker caddisflies)

7. • Leptoceridae(Long horned case maker caddisflies)
• Molannidae(Hood Case maker caddisflies)
• Odontoceridae (Strong Case maker Caddisflies)
• Philopotamidae(Finger net Caddisflies)
• Phryganeidae(Giant Case maker caddisflies)
• Phryganeidae(Giant Case maker caddisflies)
• Polycentropodidae (tube making and Trumpet Net caddisflies)
• Psychomyiidae(Tube making and trumpet net caddisflies)
• Rhyacophilidae(Free living caddisflies)
• Sericostomatidae(sericostomatid case maker caddisflies)
• Uenoidae ( Uenoid case maker caddisflies)

8. Caddisfly(Order-Trichoptera)

9. Thysanoptera
• This name is derived from latin name “thysano” means fringe or tassel, “ptera”
means wings. It relates to both pairs of wings being fringed with long hairs.
• It has 2 suborders i.e. Telebrantia and Tubulifera (Verginiatech, 2019).
Characteristics
• Thysanopterons are minute, elongated insects that may be wingless or may have
four narrow wings fringed with long hairs.
• Mouthparts elongate into stylets fitted for piercing plant tissue or sucking blood of
mites and small insects or plant sap.
• Abdomen elongate and usually cylindrical.

10. • They often crawl with the abdomen curved up over the back. Parthenogenesis
occurs in this order and males of some species are unknown.
• Metamorphosis is a modification of the hememetabolous type: there are two larval
stages followed by two or three inactive pupal stages.
• They have one to several generations per year and adults or immature overwinters
in debris.
• Most insects feed on flowers, leaves, buds, fruits and many species are serious
pests of crops.
• Few insects feed on fungal spores, mites and small insects. Some transmit plant
viruses also.
Different families
• These insects are generally classified into two Suborders (Terebrantia and
Tubulifera) and 14 Families, of which five families are known only from fossils.
The nine families of recent thrips include 774 genera and 5938 species, whereas
fossil thrips taxa are represented by 57 genera and 153 species distributed across
12 families (ThripsWiki 2013).

11. • The currently accepted classification of the Terebrantia recognizes eight
families, whereas a re-classification recently proposed by Bhatti (2006)
recognizes 28 families and 10 superfamilies for the 2400 species. Bhatti (1994,
1998) recognised 11 small families, for a total of 96 speciesin Tubulifera order.
• Out of these families economically most important family is thripidae.
Thripidae
• It is the largest family in this order and contains most of the species of
economic importance.
• The wings are relatively narrow, the ovipositor turns downward, and the
antennae are 6-9 segmented. Example banded thrips (Aelothrips fasciatus),
Mullein thrips, green house thrips etc.

12. THANK YOU