HOW TO KNOW THE IMMATURE INSECTS 



The Neuroptera, Hemiptera, Diptera, Lepidoptera. Coleoptera and 

 Hymenoptera are only partly aquatic. Some Collembola live on the 

 surface of water. 



2. Phytophagous Insects. — Most insects feed on plants. We can find 

 them on or in the plants. Others in like manner feed in dead woods 

 or decaying plant materials. All these are said to be phytophagous. 



3. Parasitic Insects. — Those insects that secure their food by living 

 within other animals are known as endoparasites. Ectoparasites live 

 and feed on other animals from the outside as with lice. Many insects 

 live within dead or decaying animal and plant materials and are said 

 to be sapiophagous. 



4. Subterranean Insects. — These insects exi.st beneath the surface of 

 the soil. Most of the orders contain some species with subterranean 

 habits. Remarkable examples are ants, termites, social wasps and 

 bees which live together of their own. Numerous insects lay their eggs 

 in the soil, such as the grasshoppers, earwigs, beetles, flies, etc. Among 

 the Coleoptera, the Cicindelidae, Carabidae, Scarabaeidae, Meloidae 

 and Elateridae are outstanding examples. With the Diptera, the Tipu- 

 lidae, Bibionidae. DoUchopodidae, Rhagionidae, Empididae, Asilidae, 

 Bombyliidae and Anthomyiidae commonly hide the eggs within the 

 ground. Lepidopterous larvae and pupae frequently hibernated in the 

 soil. Comparatively few nymphs dwell in the soil except certain root- 

 feeding Aphididae and Coccidae and the immature mole crickets. The 

 cicada nymphs on the other hand spend a long time underground. 



B. SOME CHARACTERISTIC MARKINGS: 



1. Damaged Plants. — Defoliated plants, skeletonized or partial eaten 

 leaves, holes bored in plant stems or in fruits, etc., are good indica- 

 tions for locating the insects which did this damage. 



2. Associated Animals. — When a collector sees busily working ants, 

 he can find aphid colonies near by. From the noise of bees or flies, 

 we can often find their nests or their larval breeding places. On the 

 host animals, we can usually find predators and parasites. 



3. Sweet Secretions. — A number of insect families, such as the Chir- 

 midae, Aphididae and Coccidae give off a molasses-like sweet secre- 

 tion known as "Honey dew". This is easily observed and helps to 

 locate the insects producing it. 



4. Insect feces. — Many caterpillars for instance eat such large 

 quantities of coarse foods and discharge such large amounts of waste 

 material from the digestive tract as to give a clue to their presence. 

 Furthermore, from the characteristic shape of the feces, certain species 

 can be identified. 



5. Abnormality of Plants. — Not only the abnormal growth of plants 

 but also the malnutrition of plants can lead us to find the insects re- 



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