INSECT SUCKERS AND BITERS. 207 
and branches of shrubs, looking like little lumps upon 
the stem, so that while the cuckoo-spit is protected 
by its froth the scaly plant-lice often escape by their 
likeness to the colour of the shrub on which they are. 
It is to these animals that the beautiful cochineal 
insect of Mexico belongs, and also the lac insect of 
India, which gives out the red lac used in the manu- 
facture of sealing-wax. 
All these are plant -suckers, and rarely move 
any distance from their home ; but there is another 
group which has learnt to run actively in search 
of food, of which some suck the juice of plants, 
while others have made use of their sharp lancet 
mouths to steal the blood of animals. These active 
suckers are the air-bugs and water-bugs; and though 
we dislike the name because one ugly wingless 
species haunts our own rooms when we do not keep 
them clean, yet many are very beautiful creatures. 
The little yellow and black " mitre insects " which 
overrun our raspberries and cherries and suck their 
juice, are pretty plant-bugs, though not so striking 
as the red and black bug (P, Fig. 70) which infests 
the cabbages in French gardens. Yet these plant- 
suckers are not pleasant visitors, for if you touch or 
frighten them the disagreeable smell which they will 
give out from their bodies will suggest to you at 
once that they belong to the bug family. 
Then there are those curious thin-bodied insects 
which skim over the ponds in the summer, actually 
running on the top of the water, for which reason 
they are called " water -measurers " (m, Fig. 71), 
because their legs when stretched out seem to mea- 
sure off the water as they go along. These ghost- 
