260 HEMIPTERA. 



The potato is attacked by T. minutissivia (fig. 149, 6 and 8), 

 hut it seldom does much harm : the yellow larva has black eyes 

 in this species, the pupae are also of the same colour ; the adult 

 is pale-brown, with almost white wings, and is only |- of a line 

 in length. The Thrips hibernate at the roots of grass and 

 amongst rubbish, and come forth in spring, when they com- 

 mence to lay their eggs. Numbers of generations are produced 

 in the year. The eggs are very small white bodies, cylindrical, 

 and rounded at one end, and usually laid in slits cut in the 

 plant tissue. Several species of Thrips damage plums, apples, 

 and pears ; the chief is I]uthrips pyri. 



Prevention and Reme<liei<. — After an attack of Corn Thrips 

 the stubble should be burnt, and the grass at the headlands and 

 hedgerows cleared and burnt in the late autumn. In green- 

 houses frequent syringing with clean water will keep this pest 

 in hand, but tobacco and soap wash is the best remedy. In 

 bad attaclfs greenhouse plants are best dipped in a mixture 

 of the latter. Fumigation with tobacco is another excellent 

 remedy in glass-houses. In fruit plantations it can be controlled 

 by spraying with the same wash. 



HEMIPTERA. 



Bugs, Plant-lice, Scale Insects, Etc. 



The Hemiptera are the Bugs, Plant -lice, Scale Insects, 

 Cicadas, and Lice (Pediculi), &c. The characteristics of the 

 Hemiptera are chiefly found in tlie mouth and the wings. The 

 mouth parts of all the Hemiptera are adapted for piercing and 

 sucking. The mouth is formed of a jointed rostrum made up 

 of an elongated labium, which forms a jointed sheath for the 

 lancet-shaped mandibles and maxillae. It is by means of this 

 piercing suctorial mouth that the Bugs and Plant-lice puncture 

 the rind of plants and then proceed to suck out the sap, often 

 leaving behind a distinct scar where the proboscis has entered 



