annulosa: insecta. 



259 



Order IV. Hemiptera. — Mouth suctorial, beak-shaped, 

 consisting of a jointed rostrum, composed of the elongated 



Fig. 87. — Hemiptera. Bean Aphis [Aphis/alisj, winged male and wingless femalti. 



labium, which forms a jointed, tubular sheath for the bristle- 

 shaped styliform mandibles and maxilte. Eyes compound, 

 usually with ocelli as well. Two 

 pairs' of wings in most ; sometimes 

 wanting. 



The Hemiptera live upon the juices 

 of plants or animals, which they are 

 enabled to obtain by means of the 

 suctorial rostrum. Amongst the more 

 familiar examples of this order are 

 the Plant-lice (Aphides, fig. 87), the 

 Field-bug {Pentatoma), the Boat-fly 

 {Notonectd), the Cochineal Insects 

 \Cocct), and the Cicadas. The order 

 is divided into the following two 

 sub-orders : — 



Sub-order a. Homoptera. — The 



anterior pair of wings of the 



same texture throughout 



(membranous) ; the mouth 



turned backwards, so that 



the beak springs from the 



back of the head. The wings 



fold over one another when 



the insect is at rest. The 



three segments of the thorax 



are united in a mass, and the 



pro-thorax is generally shorter Fig. 88.— Ortiioptera The com- 



*, . ° ,, •* rni_ nion Cockroach {Blaua orienta- 



than the meSO-thoraX. 1 here lU) male and female. 



the larvae differ from the aflult only in size, in having fewer joints to the 

 antennae, and in having a smaller number of facets in each of the com- 

 pound eyes. 



