86 THE AGRICULTURAL PESTS OF INDIA. 



They are useful to man. They excavate cup-shaped 

 hollows, at the bottom of which they lie in ambush and 

 seize the insects that fall down the smooth sides. 



N 



Necrophorus. See Coleoptera; Silphidse. 



Necera lepida, Cramer, the Limacodes graciosa, West., 

 short, broad, pale-green, with black spines, which feeds on 

 the Carissa jasminiflora, stings with fury. It occupies 

 also the Thespesia populnea, and at a certain stage of its 

 growth descends by a silken thread and hurries away. 



Nepa cinerea, Linn., commonly called water scorpion 

 or water spider, is a hemipterous insect, belonging to 

 the section Heteroptera, and to the family Hydrocores. 



Neuroptera, the lace -wing order of insects, to which 

 belong the termes, white ants, of the family Plani- 

 pennes. The larvse attack growing and dead vegetable 

 matter. Examples of this class are May flies, dragon 

 flies, winged white ants. 



Nicotiana tabacum, Linn., and N. rustica, Linn., are 

 said in the North- Western Provinces never to be attacked 

 by insects. The leaves occasionally suffer from a grey 

 mildew called ' kapti ' in the Azamgarh district. 

 D. & F. Vern. TamaJca, 



Noctua exclamationis, the khumwa of the Assamese, 

 the heart and dart moth, is the common pest of field and 

 garden crops. In the caterpillar stage it attacks the 

 young poppy plant, cutting across the stalk close to the 

 surface of the soil, and in a night will cut down fifty to 

 a hundred or more plants. The caterpillar is nearly 

 cylindrical, and 1J to 2 inches long. 



