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UNITED STATES DEPARTMENT OF AGRICULTURE 
Contribution from the Bureau of Entemology 
L. O. HOWARD, Chief 
Washington, D. C. PROFESSIONAL PAPER October 25, 1920 
THE BEET LEAF-BEETLE. 
By F. H. CHITTENDEN, Entomologist, and H. O. MarsuH,” Scientific Assistant, 
Truck-Crop Insect Investigations. 
CONTENTS. 
Page. Page. 
HMO UGE ON Sas ea ASE 5B UTES TPO ea ae ea, Oe ald Sea 14 
WeScriptlOn. — 9. as se eS 1 Natural enemies and other checks_- 16 
DT Sererb itl OM wees Se ee Se ee 4 Experiments with insecticides______ 19 
REPOS Of in URLeS= == eee 5 Recommendations for control_____- 21 
SOO Grp la mts = es ee ee Ali UTA Tyee eee ee ae 22 
Occurrence and extent of injury___ 8 niteratumren Clie ers — =e ee 2 
Dat eCRO IS COLY wees fe ee 10 
INTRODUCTION. 
In the Rocky Mountain States sugar beets are subject to attack 
by the beet leaf-beetle, known in some localities as the “alkali bug,” 
and in others as the “ French bug.” The principal injury caused 
is due to the attack of the larve, although the beetles also inflict 
considerable damage, hundreds frequently. being found on a single 
plant, which is entirely consumed or so injured that it shrivels 
and dies. (See Pl. L.) 
Injurious attack first attracted attention during 1897 and 1898, 
when injuries were noted both in New Mexico and Colorado. Prior 
to that time this insect was not known to injure cultivated plants, 
having confined its attack to such weeds or wild plants as the sea- 
blites, Russian thistle, and saltbush. 
DESCRIPTION. 
THE ADULT. 
This insect is related to the imported elm leaf-beetle,? and is of 
similar appearance to that species in the larval, pupal, and adult 
stages, but it is considerably larger, and the beetle has a longer thorax, 
and is differently marked. 
1 Monoxia puncticollis Say.; order Coleoptera, family Chrysomelidae, 
2 Deceased. 
3 Galerucella luteola Mill, 
186598°—20 1 
