This document discusses insects as pollution indicators. It defines pollution and bioindicators. Insects are effective bioindicators because they are abundant, respond quickly to environmental changes, and are sensitive to detecting early changes. Certain insect groups like dragonflies, mayflies, caddisflies, and stoneflies indicate water quality, while beetles, collembolans, ants indicate soil quality. Light and noise pollution disrupt insect behaviors and life cycles. Industrial pollution can biomagnify through food chains. Honey bees, moths, and syrphid flies indicate air quality issues. Insects make good bioindicators to monitor overall ecosystem health.

1. INSECTS AS POLLUTION INDICATOR
Submited To
Dr. Amritpal Singh Kaleka
Presented by:
Rahul Ranjan
Department of Zoology and Environmental Sciences
Punjabi University, Patiala

2. WHAT IS POLLUTION ?
 Pollution is addition of harmful substances (solid, liquid,
gaseous and even light) to the environment which has
negative effects.
 These effects are like degradation of natural resources
and nature.
 Effects of pollution are slow and gradual but last long.
The major types of Pollution are as follows:
I. Water Pollution
II. Terrestial Pollution
III. Air Pollution
IV. Noise Pollution and
V. Light Pollution

3. WHAT IS BIOINDICATOR ?
 Species of an ecosystem which can be used to
study or assess ecological performance and
sensitive against changes in their environment,
called as bioindicator.
 They indicate or show how changes are taking place
and are used to monitor the overall health of an
ecosystem.
 Bio-indicators can tell us about the cumulative
effects of different pollutants in the ecosystem.

4. INSECTS AS BIOLOGICAL INDICATOR
 Insect is an organism with three pair of legs,
body is divisible into three parts (head, thorax
and abdomen) and presence of compound
eyes.
 Insects are used as bio indicators because
they are the most abundant animals in almost
all ecosystems and can be used to evaluate
the impact of environmental changes.
oIt respond quickly to environmental changes
and show high sensitivity for detecting early
changes in their geographical area.

5. HOW ARE THEY USED ?
oDifferent bioindicators are sensitive to different types of
changes, it is being used as following categories:

6. BIO-INDICATOR GROUPS OF INSECTS
1. Dragonflies and
damselflies
2. Mayflies
3. Caddisflies
4. Bugs
5. Stoneflies
6. Honey bees
7. Beetles
8. Collembolans
9. Butterflies and
Moths
10. Ants
11. Syrphid fly

7. INSECTS AS WATER POLLUTION INDICATOR
o Insects which live completely or carry a major part
of their life cycle in water can tell directly about
water pollution.
o Larvae of mosquitoes, odonates and neuropterans
can only live in fresh water. Absence of these larvae
indicate towards presence of Arsenic and Lead
concentrations in water.
o Several aquatic insects groups can be used as
aquatic environment bioindicators, which is as
followes:

8. DRAGONFLIES AND DAMSELFLIES
 Dragonflies and damselflies
(known collectively as the
“Odonata”) are an important group
in biological water quality
monitoring, as they are particularly
sensitive to pollution.

9. MAYFLIES
 Mayflies (Ephemeroptera) larvae are
recognized worldwide for their sensitivity to
oxygen depletion in running waters, and are
therefore commonly used as bioindicators in
many monitoring programs.

10. CADDISFLIES
 Caddisflies (Trichoptera) are the group
of insects whose larvae occur in all
types of fresh water. Particular species
are sensitive to water pollution and
that’s why they are used as bio
indicators of water purity.

11. STONEFLIES
 Stonefly (Plecoptera) larvae can only live in
clean water, these flies indicate high oxygen
water.

12. BUGS
 Bugs belong to order Hemiptera,
many families like Corixidae,
Nepidae, Notonectidae, Pleidae,
Belostomatidae, Gerridae,
Veliidae and Mesoveliidae are
also act as bioindicator to
determine the quality of water.

13. oLand insects are good bioindicators in various types of
environmental change.
oOccurrence of excess acidic or alkaline content, fertilizers or
industrial waste kills larvae, nymphs and adults of these
insects.
oPolluted land areas are not fit for insects to lay eggs.
oSeveral insects groups can be used as terrestrial
environment bioindicator, which is as follows:
INSECTS AS TERRESTRIAL POLLUTION
INDICATOR

14. BEETLES
 The Order Coleoptera is the largest order
of class insecta and plays roles in
maintaining soil quality, and contributes to
the physical and chemistry soil formation.
 They also participate in biological control
and biological monitoring of pollution from
oil, Sulphur, Carbon dioxide and
insecticides.

15. COLLEMBOLANS
 Collembolan are primitive insects that have
influence on soil fertility by microbial activity
stimulation.
 They are very sensitive to change in soil caused by
pollutant such as heavy metals, pesticides and soil
acidification in agricultural crops.

16. ANTS
 Ants are very sensitive to human impact, and
could be used as environmental indicators in
different ecosystems depending on the
degree on environmental change, and these
changes reveals the extinction of many ant
species.

17. INSECTS AS LIGHT POLLUTION INDICATOR
Excess exposure to light disturbs the
developmental cycle of many insects. Their
daily activity regime or biological clock is
negatively effected.
 Heavy flash lights at night have already
disturbed life cycle of moths and may flies.
Under effect of such light these insects have
lost their orientation cues to search for host
plants.
 The monarch is the only butterfly known to
make a two-way migration like birds. They use
a sophisticated navigation system to guide
them in their journey south for the winter.
Research has shown that exposure to artificial
light can disrupt their navigation system,
disorienting them from their migration routes.

18. INSECTS AS SOUND POLLUTION INDICATOR
 Sounds are an important part of social insects
life history. Generally males produce
advertisement calls to attract females or to
drive out competitive males out of their
territory.
 Negative effect of vehicular horns, noise of
moving vehicles and other sources suppress
the advertisement call of male insects hence
destroying their mating cycle and thus
decreasing their numbers.
 Sound pollution has extreme negative effect
on cicadas, crickets, locusts and grasshoppers
mainly.

19. INSECTS AS INDUSTRIAL POLLUTION INDICATOR
 Industrial pollution pollutes the entire ecosystem as whole.
 Unprocessed industrial output, when enters ecosystem leads to a
phenomenon called biomagnification.
 Biomagnification – When a carcinogenic or toxic substance is
consumed by primary trophic unit and consequently reached every
trophic level in a food chain with increased potency. Thus,
hampering the complete system.

20. oFamous example of effect of Industrial Revolution on
moths is British population of Biston betularia.

21. INSECTS AS AIR POLLUTION INDICATOR
 Air pollution blocks trachea/spiracle
openings of insects.
 Orientation cues of insects to search host
plant, mate or ovipositional sites are
damaged.
 Several insects groups can be used as air
pollution indicators, which is as follows:

22. HONEY BEES
 The honeybees (Hymenoptera)
act as bioindicators of
environment in two ways as it
signals via high mortality rates
due to the presence of toxic
molecules or via residues in
honey, pollen and larvae the
presence of heavy metals.
 Recent mass dying out of
Honey Bee in United States of
America because of fertilizers
has brought Honey Bee to list of
endangered species.

23. LEPIDOPTERANS
 Some lepidopteran groups are used as
environmental indicators by heavy metals and
carbon dioxide concentration in locations close to
industrial and even within urban areas.
 Presence and consequences of copper, iron,
nickel, cadmium, and other substances used in
fertilizers were studied with pupae of different
Geometridae and Noctuidae species, cycle
duration and mortality rate of newly hatched
butterflies larvae which feed on plants subjected to
high CO2 concentrations.

24. SYRPHIDFLY
 These flies belong to family Syrphidae, one of
the largest family of Diptera has wide
distribution and well known taxonomy and its
larvae require different environmental
conditions, which make these flies good bio
indicator.

25. CONCLUSION
 The use of bioindicators is essential for
environmental monitoring.
 The main characteristics of a bioindicator are:
richness and diversity species, ecological
faithfulness, fragility to small environmental
changes and good organism responses.
 Class Insecta has all of them. Therefore, this study
concluded that the Class Insecta has many
potential representatives that can be used as
environmental bioindicators.