HOW TO KNOW THE IMMATURE INSECTS 



3b. 9th abdominal segment with terminal process bent downward and 

 directed toward a similar but upward bent process from the stern- 

 al plate; leg (in instar in which fully developed) provided with a 

 long, slender tarsus carrying 2 claws of equal length. 

 Fig. 168 Family MICROMALTHIDAE 





*i^Ec rs OF 



Fig. 168. Micromaithus delibis Lee. 



It consists of a single North 

 American species, Miciomal- 

 thus debilis Lee. The biology 

 of this insect is most remark- 

 able. It combines in its life 

 cycle 7 or 8 forms of larvae, 

 and exhibits both oviparous 

 and ovoviviparous paedogene- 

 sis. 



4a. Cardo very large; 2 pairs of gills on the tip of 9th abdominal 

 segment. Fig. 169 Family GYRINIDAE 



They are called whirligig beetles or surface 

 swimmers. There are about 450 described spe- 

 cies. The eggs are laid on objects in water. The 

 larvae are aquatic and predacious. They pu- 

 pate in flimsy cocoons attached to rocks, water 

 plants, etc. 



Fig. 169. a, Dineutes 

 sp.; b. Maxilla of a 

 gyrinid larva. 



4b. Cardo of normal moderate size or small; never have 

 2 pairs of gills on the tip of 9th abdominal segment. 

 Fig. 170 5 



/) CMiAmia 



Fig. 170. Maxil- 

 la of a carabid 

 larva. 



74 



