382 



Marvels of Insect Life, 



visible to the unassisted eye, which holds a film of air and so prevents the Insect 



gettin.g wet, even when submerged. A 



Sea-Skaters. 



These remarkable little Insects — actually only half the size of their 

 photographs — live entirely on the surface of the ocean, often nianv 

 hundreds of rniles from the nearest land. 



Photo by] [E. Step, F.L.S. 



Giant Water-Bug. 

 This huge Insect, alUed to the water-scorpion of our ponds, is a rather 

 formidable native of South America and Trinidad, which catches 

 fishes and frogs with its mantis-like fore-feet. Natural size. 



1 Hydrometra stagnorum. 



ection made across the hind-body would 

 show that it is boat-shaped, the sides 

 being continued slightlv over the back 

 to form bulwarks as it were. 



In one species, known as the 

 water-gnat, 1 the general form is much 

 like that of a stick-Insect on a very 

 small scale. One-third of the entire 

 length of the trunk consists of the head, 

 which is drawn out to an inordinate 

 length, and the eyes arise from the 

 hinder half of the head. All its legs 

 are long, and its antenme are pro- 

 portionate to them ; so that the super- 

 ficial likeness to a stick-Insect is com- 

 plete. Two of these skaters will be 

 found illustrated on page 162. 



Built on somewhat similar lines 

 to the ditch-skaters, but very much 

 larger, is the ranatra,"^ which might 

 well be passed over as a length of 

 broken reed-stem. It is not in the 

 liabit of skating over the surface, but 

 lies cpiietly below with its long re- 

 spiratory tube reaching to the surface, 

 and for short periods ranges along the 

 bottom in quest of food, mainly the 

 grubs of other Insects. A near rela- 

 tion is the very dissimilar water- 

 scorpion, and another is the gigantic 

 belostoma, with whose histories and 

 habits we have already dealt (see 

 pages 24 and 161). 



What one may call the sea- 

 skaters '"^ more nearlv resemble gerris 

 than they do the last-mentioned ; 

 but the hind-body is so greatly abbre- 

 viated as to look as though the major 

 part of it had been bitten off by some 

 other denizen of the deep. A number 

 of species are known from various 

 parts of the ocean surface, where 

 it gets sufficiently warm for Insect life ; 

 but so far no soecies have been found 



^ Ranatra linean'r. '" Halobates. 



