﻿2 BULLETIISr 1357, U. S. DEPARTMENT OF AGEICULTURB 



these reports proved them to be the chrysomelid beetle referred to 

 above. Unfortunately the name " strawberry rootworm " does not 

 imply that the greenhouse rose is a host or food plant, but in view 

 of its long standing this name must be retained. 



An investigation of these reports revealed the seriousness of the 

 situation and indicated that the rose-growing industry was con- 

 fronted with another important problem. Moreover, according to 

 their statements, the florists were unable to check the ravages of 

 these beetles by the use of measures ordinarily employed for con- 

 trolling leaf-feeding insects. A review of the available literature 

 on this species indicated that little was known of its life history and 

 habits under greenhouse conditions. Naturally, owing to the change 

 from the normal temperate climate out of doors to the subtropical 

 conditions prevailing under glass, and to the intensive and special- 

 ized culture of the rose, important differences in biology and control 

 would result. 



The data collected during the last three years of research on 

 the biology and control of this insect under conditions which 

 exist in commercial greenhouses are presented in this publication. 



SYSTEMATIC HISTORY 



The two forms of the strawberry rootworm beetle encountered in 

 the greenhouse and covered by these investigations appear to be 

 Paria canella quadrinotata (Say) and P. canella gilvipes (Crotch), 

 but so much conflict of opinion is apparent among various authorities 

 who have published upon this group of beetles that the status of 

 these varieties or species is still a matter of conjecture. The follow- 

 ing discussion relates to the changes in nomenclature of these two 

 varieties only. 



The first name applied to this group of forms was OryptocepTiahis 

 aanellus, given by Fabricius (9, p. S2) in 1801. Seven years later this 

 was changed to Eumolpus canellus by Olivier {22^ p. dllf)- In 1824 

 Thomas Say {%6^ p. li.lfi) first described as Colaspls quadrinotata the 

 four-spotted form here treated. In 1858 LeConte {W.. p. 86) erected 

 the genus Paria for five species, including canella and quadrinotata. 

 In 1873 Crotch (7, pp. SS, 39) , in revising the North .-^jnerican eumol- 

 pids, distinguished the genera Typophorus and Paria and placed 

 quadrinotata (misprinted " 6-notata ") and gilvipes as varieties of 

 Paria sexnotata Say. In 1882 Jacoby {18^ p. 182) mentioned Paria 

 as very closely related to Typophorus, but kept the two genera sep- 

 arate. In 1884 Forbes {13, p. 169) in his economic treatise asso- 

 ciated quadrinotata and gilvipes as synonymous with Paria sex- 

 notata Say. 



In 1892 Paria and Typophorus were united by Horn {16, p. 208) , 

 in his monograph on the Eumolpini of Boreal America, under the 

 older name Typophorus. He listed canellus as one of the two in- 

 cluded species and reduced all of the other specific names used under 

 Paria to the rank of varieties or synonyms under canellus, in which 

 he placed quadrinotatus as a variety, and gilvipes as a subvariety of 

 the variety aterrimus Oliv. In 1910 Blatchley {2, pj. 1139), in his 

 Coleoptera of Indiana, followed Horn's nomenclature for the forms 

 above mentioned. In 1914 Clavareau (4, pp. 153-157) catalogued 



