Insects in Aquatic Ecosystem

Suprabha PALB 4109

What is an Aquatic insects ???

Importance

Habitat of Aquatic insects ???

Adoptions of aquatic insects ???

Uses of aquatic insects???

One million known insect species, there are over 8000 species that fall into the macro invertebrate category

All living organisms in aquatic environments fall into one of the four categories:

1. Plankton - Drifters 2. Nekton - Free-swimmers 3. Benthos - bottom dwellers4. Pleuston - air water interferace

Aquatic Ecosystem

(Danks , 2002)

Truly aquatic insects are those that spend some part of their life-cycle closely associated with water, either living beneath the surface or skimming along on top of the water

The immature stages are truly aquatic while the adult is a winged terrestrial form.

(Subhashini et al ., 2008)

Aquatic insects

Aquatic Insect Orders

1. Collembola*

2. Ephemeroptera **

3. Odonota**

4. Plecoptera**

5. Hemiptera

6. Megaloptera

7. Neuroptera*

8. Trichoptera**

9. Lepidoptera*

10. Coleoptera

11. Hymenoptera*

12. Diptera

* ---- Minor aquatic order with only a few aquatic species ** ---- Entirely aquatic orders 12

2912 orders ,150 Families ,8600 Species

1 mm

21 cm

Small and Larger Aquatic insects

Megaloptera Hymenoptera

Ephemeroptera May fly - 21 families with 676 species

Eggs –Nymph– Adult

Naiads often with abdominal gills

Maxillary and labial gills

3 styli on naiads and adults

Nymph (Predacious)

Adult ( do not feed)

Upto 45 instars

( Voshell et al ., 2002 )

Eggs –nymph–adult Up to 20 instars Predacious Gills present Mask present

Odonata Dragon fly, Damsel fly- 9 families with 407 species

Damsel fly

Dragon fly

( Voshell et al ., 2002 )

Plecoptera Stone flies- 9 families and 626 species

Mostly temperate regions

Anal gills

10-33 instars

Need high oxygen, good

environmental indicators.

Water purity indicator

( Voshell et al ., 2002 )

Hemiptera Back swimmers, Water Boatmen, water bugs , water strider,

water scorpions

Diving or at surface

Adults and naiads both aquatic.

Highly modified legs.

Generally wings still functional as

adults, can disperse between

waterways.

( Voshell et al ., 2002 )

Coleoptera Diving beetles, Whirligig beetles, Scavenger beetles

Egg – larva –pupa – adult

Larva very different from adult

Adults – have hard case on body that does not

overlap

Adults have chewing mouthparts

Predatious

Coleoptera

( Subramanian and Sivaramakrishnan, 2007 )

Diptera Mosquito , Meniscus midges, Chironomids

29 families and 3,500 species

Larvae are maggot like or worm like

Very diverse in aquatic ecosystem

Anal spiracles breathing at surface

upto 5 instars

( Subramanian and Sivaramakrishnan, 2007 )

Diptera

( Subramanian and Sivaramakrishnan, 2007 )

Trichoptera Caddisflies - 21 families and 1,400 species

Caddisflies are related to

Lepidoptera and resemble small hairy

moths

Wings are covered in dense hairs

rather than scales

Upto 6-7 instars

The larvae may be either

herbivorous or predatory

Trichoptera

( Subramanian and Sivaramakrishnan, 2007 )

Megaloptera Dobsonflies and Alderflies

Gills present Complete metamorphosis Larvae of some of the larger kinds are called hellgrammites,

which are popular as live bait for smallmouth bass and other warm-water fish species.

Dobsonfly Alderfly

( Subramanian and Sivaramakrishnan, 2007 )

Habitat of Aquatic insectsCollembola Ephemeroptera Odonota Plecoptera

Hemiptera Trichoptera Coleoptera Diptera

Springs and spring ponds Lakes and Streams Lakes and Streams Streams

Lake and Stream Margins

Lakes and Streams Lakes and Streams All Aquatic Habitats

( Ronald et al., 2007 )

Structure and Appearance

Lifecycle and Development

1. Slow season life cycle - Mayflies, Stoneflies, And Caddisflies 2. Fast season life cycle - caddisflies and dragonflies

3. non seasonal life cycle - Hellgrammites

Life cycles for aquatic insects may be very short or very long

( Voshell et al ., 2002 )

Lifecycle and Development

( Hope Batcheller, 2010)

Food sources & Feeding mechanism

1. Scrapers2. Collectors3. Shredders4. Predators

Food sources - Functional feeding groups

Categorize:

(Reese , 2009)

Scrapers special mouthparts that

remove algae growing on the surface of rocks or other solid objects

Collectors

acquire small pieces of decaying plant material (detritus)

Feeding mechanism

(Reese , 2009)

Shredders aquatic insects feed on

parts of live plants that grow under the water.

Predators

feed on other animals that are alive (small

vertebrates, such as fish and tadpoles)

Feeding mechanism

(Reese , 2009)

Use oxygen that is dissolved in the water

Immature stages – Gills –obtaining dissolved oxygen - water

Use the holes in their bodies to get oxygen from the air – Respiratory siphon

Spiracles on the end of a long tube at the end of their abdomen ( water beetle)

Respiration

( Reese Voshell , 2009)

2. Snorkel with a breathing tube :

- Mosquito larva and water scorpions 3. Scuba tank :

- Water beetle and Water Spider

1. Gills : - May fly , Dragon fly , Stone fly , caddish fly

Respiratory adoptions

Reproduction

Only adult insects are capable of reproducing, and most aquatic insects spend their adult stage out of the water

After mating on land, females return to the water to deposit her eggs

Eggs are usually stuck on solid objects under water, but a few kinds deposit the eggs on trees or rocks above the water

( Hodkinson and Jackson , 2005 )

Reproduction

Ephemeroptera Odonota Diptera

Coleoptera Trichoptera Plecoptera

Other aquatic adoptions1. Ripple effect:

(Hershey et al ., 2008)

signals are usually produced by vertical oscillations of the legs which remain in contact with the water.

Ripple signals occur in the contexts of calling and courtship (precopulation), copulation, postcopulation, sex discrimination, induction of oviposition, individual spacing, territoriality, and food defence

Water striders, Giant water bugs and Whirligig beetles

2. Double vision

The Whirligig Beetle has eyes divided vertically to see both under and above water.

upper

lower (Hershey et al ., 2008)

3. Oars

Many aquatic insects paddle underwater with oar-like legs Legs are long, flattened and fringed water beetle and water boatman

(Hershey et al ., 2008)

4. Skates

Aquatic insects skate on the water surface by distributing their body weight over long, thin, waterproof legs.

They paddle with the middle pair of legs, steer with the hind legs and use the short front legs to attack and hold prey

(Englund , 2007 )

5. Jet skis The Camphor Beetle also skates on the water surface.

When alarmed, it releases a chemical from its back legs

that reduces the water surface tension

( Choudhary and Ahi , 2015)

1 meter / second

5. Suckers

Blephariceridae, commonly known as net-winged midges

Found near fast-flowing streams where the larvae live

Suckers are sometimes called creeping welts

Immature stagesAdult( Choudhary and Ahi , 2015)

Importance of Aquatic Insects

Major component of the aquatic food web

Indicators of aquatic health

Affect human health

Role in forensic investigation

Business partner

Aquatic insects and Water quality Hazardous chemicals, automotive products, pesticides,

fertilizers, pet wastes, excessive soil erosion and air pollution all contribute to water pollution.

Mayflies Stoneflies Caddisflies Making survey of aquatic insects is called “ Bio monitoring”

(Kaur et al ., 2010)

Role in Aquatic Food web

( Baxter et al., 2005 )

Algae → Protozoa → Small Insects → Large aquatic Insects → Small fish → Large fish

IbisbillIbidorhyncha struthersii

1. Malaria 2. Kala Azar 3. Dengue 4. Plague 5. Filariasis 6. Chickungunya 7. Lyme disease 8. Yellow fever 9. Chagas’ disease 10. Japanese encephalitis

Mosquito v/s Human

(WHO, 2015)

Zika virus outbreak - 2015 The outbreak began in April 2015 in Brazil, and has spread

to other countries in South America, Central America, Mexico, and the Caribbean

The virus is spread mainly by the Aedes aegypti

Role in forensic investigations

1. Ephemeroptera

2. Odonota

3. Plecoptera

4. Hemiptera

5. Trichoptera

6. Coleoptera

7. Diptera

(Merritt and Wallace , 2010)

(Merritt and Wallace , 2010)

ETP Group

HemipteraColeoptera

Odonata Diptera

(2-13 days)

(14-38 days)

(39-161 days)

(161-225 days)

(225-338 days)

In 2007 profile of Hubert Duprat's work with caddis fly larvae is a tiny, entomological miracle.

The larvae build their cocoons with whatever material is at hand

Duprat forces them to build with gold and precious gems, making spectacular bio-organic jewelry

Business partner

(Duprat , 2007)

Case study

- Relationship between some aquatic insect species (Ephemeroptera, Plecoptera,Trichoptera and Odonata) and some heavy metals (cadmium, lead, copper, zinc, nickel, iron and manganese) assessed using data obtained from the Ankara Stream .

Study area

(Girgin et al., 2010)

Water pollution

Danger !!!

Giant Water BugLethocerus indicus

Researchable Area

Aquatic insects of Village Irrigation Tanks

Community structure of aquatic in a Village Irrigation Tank

Changes in the diversity and Community Structure of aquatic insects due to Sewage Pollution in Bangalore Lakes

Can aquatic insects be a good indicators of pollution levels in Bangalore Lakes

Avoid Water pollution ….save us…

THANK YOU……