February, '19] hayes.- lachnosterna lanceolata 109 



THE LIFE-CYCLE OF LACHNOSTERNA LANCEOLATA SAY^ 



By William P. Hayes, Assistant Entomologist, Kansas State Agricultural 

 Experiment Station 



Introduction 



Because of the growing importance of Lachnosterna lanceolata Say 

 as a pest of growing wheat in Kansas and Oklahoma, the Hfe-history 

 study herein reported was taken up as a part of the Kansas Experi- 

 ment Station project "Insects Injurious to the Roots of Staple Crops." 

 This project aims ultimately to work out the life-histories of all other 

 Kansas species of Lachnosterna and related genera as well as wireworms 

 and other underground pests of staple crops growing in the state. 

 The work is being carried out under the immediate direction of Mr. 

 J. W. McColloch, to whom thanks are due for his kindly aid and 

 criticism. 



History and Importance 



Lachnosterna lanceolata Say, an important enemy of growing wheat in 

 Kansas and Oklahoma, was originally described as Melolontha lanceo- 

 lata Say (1824, p. 242), from specimens collected near the Rocky 

 Mountains. The remark being added that it inhabits Missouri and 

 ^'Arkansa." Since then it has been placed in three other genera — 

 Tostegoptera, Lachnosterna, and Phyllophaga. 



This insect is destructive both in the larval and adult stages. Cock- 

 erell (1895, p. 69) first reported adults injuring growing cobs of corn 

 in New Mexico. Howard (1900, p. 107) reported the adults attack- 

 ing collards in Texas, and stated that they had been "noticed more or 

 less since 1890. Their principal food was stated to be 'careless 

 weed' (Amaranthus), two or three species of which grow commonly in 

 or near cornfields." Sanderson (1904, p. 95) stated that the beetle 

 often occurs in large swarms and eats off young cotton plants on con- 

 siderable areas. In 1905 (p. 13) he again mentions the injury to 

 young cotton, as well as "various other crops, especially' garden truck, 

 in the arable land west of the ninety-seventh meridian." It is re- 

 garded as most injurious in west central Texas. The wild sunflower 

 (Helianthus) is added as a food plant. The same writer (1906,- p. 18) 

 attempted to rear the species and succeeded in hatching four eggs. 

 The resulting larvae fed on cotton and grass roots during tho summer 

 and fall. This apparently comprised the total of our knowledge of the 



1 Contribution from the Entomological Laboratory, Kansas State Agricultural Col" 

 lege, No. 3.5. Thi.s paper embodies the results of some of the investigations under- 

 taken by the author in the prosecution of project No. 100 of the Kansas .\gricultural 

 Experiment Station. 



