HOW TO KNOW THE INSECTS 



5. Hallplldae (7) The Crav.'llng Water-beetles. Small; In ponds 



and streams. Carnivorous. 



6. Dytlscldae (45) The Predacious Dlvlng-beetles. Carnivorous. 



7. Gyrlnldae (15) The Whlrllglg-beetles. On surface of water. 



Predacious . 



8. Hydrophllldae. . . . (46) The Water Scavenger-beetles. Mostly In water; 



some predacious, mostly scavengers. 



9. Platypsyllldae . . . The Beaver parasite. Found on beavers; but one 



species. 



10. Brathlnldae Rare; small; In moss. 



11. Leptlnldae (1) The Mammal-nest Beetles. Very small; In nests 



of mice and bumble bees. 



12. Sllphldae (26) The Carrion-beetles. Medium to large; eat 



decaying flesh, etc. 



13. Clambldae Very small; In decaying vegetation. 



14. Scydmaenldae .... (39) Very small; under bark or stones or In ants' 



nests. 



15. Orthoperldae .... (8) very small; in decaying vegetation. 



16. Staphyllnldae. . . . (327) The Rove-beetles. Slender, elytra very 



short; scavengers. 



17. Pselaphldae (84) Very small; similar to rove-beetles but v/lth 



fewer abdominal segments. 



18. Clavlgerldae .... The Ant-lovlng beetles. Similar to rove-beetles, 



but only 2 Joints to the antennae. 



19. Ptllldae (3) The Feather winged beetles. Includes the 



smallest beetles known. In ant nests. In dead 

 wood and leaves etc. 



20. Sphaerlldae Very tiny; on mud or under stones. 



21. Scaphldlidae . . . . (13) The Shining Fungus-beetles. In fungi, dead 



wood, etc. Tip of abdomen conical. 



22. Sphaerltldae .... Mot known to be in Iowa. Resemble Ulster Beetles. 



23. Hlsteridae (64) The Hister Beetles. Hard, round, shiny, 



mostly black. 



24. Lycidae (12) Flat, broad, flexible wings; diurnal; car- 



nivorous. 



-25. Lampyrldae (13) The Firefly-beetles. Soft bodies; nocturnal, 



carnivorous. 



26. Phengodldae (1) Similar to fireflies. 



27. Cantharldae (26) The Soldier-beetles. Long, slim, thin-winged, 



on flowers; carnivorous. 



28. Melyrldae (11) The Soft-winged Flower-beetles. One vej^y 



common Iowa species on grass, etc. 



29. Clerldae (23) The Checkered-beetles. Usually brilliant 



pattern; on tree trunks and flowers, predacious. 



30. Corynetldae (8) Similar to checkered beetles, but differing in 



tarsi. 



31. Lymexylldae Rare; elongate; narrow. 



32. Telegeusldae .... Not found in our state. 



33. Micromalthldae . . . Rare; in decaying logs. 



34. Cupesldae. . . . . . (1) Rare; under bark. 



35. Cephaloidae Small family. 



36. Oedemerldae (4) On plants or in ground. 



37. Mordellldae (57) The tumblin'^ Flower-beetles. Wedge shaped. 



110 



