52. Thorax thick and muscular; animal usually living in wood 



Coleoptera Borer Beetle Grubs 

 Body soft and stout; animal usually living in nuts, fruits, or seeds 

 Coleoptera Weevil Grubs 



53. Animal with little or no powers of locomotion; living on plants; scale- 



like or covered Vv'ith a cottony or mealy secretion 



Homoptera, Coccidae Scale Insects, Mealy Bugs, Bark Lice 

 Animal not so 54. 



54. Ajiimal minute; abdomen of not more than six segments and bearing on 



the end a pair of appendages which are usually folded under the body 

 and enable the animal to jump 

 Collemhola Springtails 

 Animal not so 55. 



55. Living in water 56. 

 Living on land 63. 



56. Back extended to form a flattened oval shield which extends over and 



hides the rest of the animal 



Coleoptera, Psephemdae and Dryopidae larvae Water-pennies 

 Not so 57. 



57. Mouth parts forming a sucking tube 58. 

 Not so " 59. 



58. Parasitic in fresh-water sponges 



J\[europtera, Sisyridae Sponge-fly larvae 

 Not so 



Heteroptera True Bug nymphs 

 (Hemiptera (part) ) 



59. With a hinged lower lip that can be extended considerably beyond the 

 head " 60. 

 Not so 6L 



60. No tail-like processes from the end of the abdomen 



Odonata, Anisoptera Dragon-fly naiads 

 Usually with three, flat, leaf-like "tails" 



Odonata, Zygoptera Damsel-fly naiads 



61. With sickle shaped mandibles (appearing like a pair of pinchers or tongs) 



adapted for sucking; usually without ''tails" 

 Coleoptera Water Beetle larvae 

 With biting or chewing mouth parts; usually with two or three "tails" 62. 



62. With tufts of hair-like filaments behind each leg but with none on the 



abdomen; "tails" two 



Plecoptera Stone-fly naiads 

 With tufts along sides of abdomen; usually with three "tails" 

 Ephemerida May-fly naiads 

 (Plectoptera) 



63. Very small and much flattened laterally; jumping; parasitic on warm- 



blooded animals. 



Siphonaptera Fleas 

 {Suctoria) 



237 



