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TEXT-BOOK OF ZOOLOGY 



for clasping the female. The latter, moreover, is distinguished from the 

 male by having its elytra (usually) furrowed. If its native pond dries 

 up or the beetle desires to find one more richly supplied with food, or 

 to spread its progeny over a wider area, it spreads its large wings and 

 takes to flight. (For this reason we must keep our aquarium covered 

 over.) The predaceous and voracious character of this insect may be 



WATER BEETLES. (Natural size.) 

 Common Water Beetle (Di/ticus) : M., Male; W., female; L., two larvae; P., pupa. 



Great 



Water Beetle (Hydrophilus) : K. W., female ; E., a packet of eggs under a leaf, shown open 

 at g.E. ; T., three whirligigs. 



easily proved by introducing other aquatic creatures into an aquarium 

 containing captive water beetles. All, from the delicate May-fly to the 

 worm and fish, fall an easy prey to it, and it even bites holes into the 

 bodies of the larger fishes and frogs. Hence the water beetle is a 

 rapidly moving creature (see above) and equipped with powerful pincer- 

 like mandibles. 



