302 ECONOMIC ENTOMOLOGY 



AA. Abdominal spiracles not situated on the membrane; upper surface of head 

 rarely dilated. — Leaf -chafers. 

 Common Economic Genera of Leaj -chafers (after Blatchley): 



A. Abdominal spiracles in part situated on superior portion of ventral segments; 

 the rows of spiracles feebly diverging. 

 B. Form slender, elongated; dull yellow; elytra densely covered with 

 scales.- — Macrodactylus. 

 BE. Form robust, heavy; brownish; six ventral segments. 



C. Small, ventral segments free; elytra with regular indistinct 

 grooves on disk. — Serlca. 

 CC. Medium sized, ventral segments connate; elytral disk without 

 grooves. — Phyllophaga = Lachnoslerna. 

 AA. Abdominal spiracles (excepting the three front ones) situated on dorsal 

 portion of ventral segments, forming two rows which diverge strongly. 

 B. Tarsal claws unequal in size. 



C. Elytra with membranous margin; antennae 9-jointed. — Anomala. 

 CC. Elytra without membranous margin; antennas 10-jointed. 

 D. Elytra with black spots. — Pelidnota. 

 DD. Elytra without spots. — Cotalpa. 

 BB. Tarsal claws equal in size. 



C. Front coxas transverse; body above convex. 



D. Head and thorax unarmed in both sexes; mandibles narrow; 

 brownish yellow. — Cyclocephala. 

 ■ DD. Head or thorax (or both) armed in both sexes; mandibles 

 toothed on outer side; clypeus bidentate; dark reddish 

 brown. — Ligyrus. 

 CC. Front coxas conical, prominent; body not convex; antennae 10- 

 jointed. 



, D. Side-pieces of mesothorax visible from above; sides of elytra 

 more or less sinuate; thorax triangular; never uniform black. 

 — Euphoria. 

 DD. Side-pieces of mesothorax not visible from above; sides of 

 elytra not sinuate; hind coxae contiguous. 

 E. Body almost glabrous; size large; color uniform. — 

 Osmoderma. 

 EE. Body pubescent; size smaller; color variegated; thorax 

 rounded at base. — Trichius. 



White Grubs {Lachnosterna=Phyllophaga, spp.). — White grubs are 

 the larvae of May or June beetles, the majority belonging to the genus 

 Phyllophaga or Lachnoslerna. The following species: L. fusca, Froh., 

 L. anxia, L. calceaia rugosa Melsh, L. Jutilis {gibbosa) ,L.Jervida {arcuata) 

 Smith, L. impUcita Horn, L. Iiiriicula, L. fraierna Harr., L. tristis 

 Fab., and L. illicis Knoch are perhaps the most abundant (Figs. 

 igS^and 199). 



