Ecological Indicators The presence of dragonflies can reveal changes in the water ecosystems more quickly than studying other animals or plants. In fact, from the nymph to the adult stage, the dragonfly has a significant, positive ecological impact. Dragonfly eggs are laid and hatched in or near water, so their lives impact both water and land ecosystems. Once hatched, dragonfly nymphs can breathe underwater which enables them to eat mosquito larvae, other aquatic insects and worms, and even small aquatic vertebrates like tadpoles and small fish and in the air. Adult dragonflies capture and eat adult mosquitoes. Community wide mosquito control programs that spray insecticides to kill adult mosquitoes also kill dragonflies.
The most effective stages in the life cycle of dragonfly that eradicate mosquitoes are-

Options

A. Larvae and adult
B. Caterpillar and adult
C. Nymph and adult
D. Pupa and adult

Answer

C

Explanation

Dragonflies are large and heavybodied insects. The larvae (or Nymphs), which live in water, eat almost anything living that is smaller than themselves. The adult dragonfly. larvae are even known to catch and eat small fish. Usually, they eat bloodworms or other aquatic insect larvae: Dragonfly nymphs are: such good hunters because they move really fast - by what looks like je propulsion:One of the benefits of having dragonflies live nearby is that they eat many times their weight in mosquitoes every day. Dragonflies also eat many different kinds of flies: Using a basketlike arrangement of their legs, adult drag onflies can actually catch and eat other bugs while they are flying