8 ; 
. ay 
) BULLETIN 1357, U. S. DEPARTMENT OF AGRICULTURE i 
A t 
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 Cryptocephalus 
canellus, given by Fabricius (9, 7.52) in 1801. Seven years later this 
was changed to H'umolpus canellus by Olivier (22, p. 914). In 1824. 
Thomas Say (26, p. 446) first described as Colaspis quadrinotata the 
four-spotted form here treated. In 1858 LeConte (20, ». 86) erected | 
the genus Paria for five species, including canella and quadrinotata. 
In 1878 Crotch (7, pp. 33, 39), in revising the North American 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. 782) mentioned Paria - 
as very closely related to Typophorus, but kept the two genera sep- | 
arate. In 1884 Forbes (73, ». 159) in his economic treatise asso-| 
ciated guadrinotata and gilvipes as synonymous with Paria sea-| 
notata Say. | 
In 1892 Paria and Typophorus were united by Horn (J6, 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, p. 1139), in his 
Coleoptera of Indiana, followed Horn’s nomenclature for the forms § 
above mentioned. In 1914 Clavareau (4, pp. 153-157) catalogued 
| 
| 
