- 56 - 
derris dust at int'^rvrls -^f ^ to 5, days, dependini-; on the weather and 
the extent of the attack:--in thr- pvent of a s-'vere attack, as many as 
five applicati'-^ns may be neces'sary; and (5) keep a very careful watch 
en the seedbeds. Durinc: fine weather they should he examined twice a 
day. A bed may be free from beetles in the morning end yet be severtly 
attacked by the eveaing of the same day. It is possible ths.t this 
method of dusting with derris may be applied to other crops subject 
t^ attack ly fie? beetles. If a lisht dust is used, ab^ut 30 pounds 
per acre per application should be enoUt-:h if the plants are in drills 
about 2 feet 6 inches apart, 
Fhyllotreta bipustulata (F.) 
Fenton ( 127 ) in 1'"'36 referred to an unpublished report by Honey, 
of the Texas Agricultural Experiment Station, wh^ found that a dust co'i- 
posed of 15 pounds of pyrethrum (0,5 percent of pyrethrins) , 10 pounds 
of derris (5 percent of rotenone), and 75 pounds of sulfur successfully 
controlled these beetles, 
Fhyllotreta consobrina ( Curt , ) 
P. cruciferee (Goeze) 
F, nemr-rum (L.) 
See Fctherbrid.T- and Thomas ( "^17 ) ^andrr Fhyllotreta atra (F.), 
on pa^ce 55* 
Fhyllotreta nigrip'^'S (F,) 
See Foth.--rbrid:re and Thomas ( "517 ) under F. atra (F,), on page 5^. 
Blunck o.nd M'-yer (30) in 113^ reported derris powder and Folvo 
to be effecti^'p for combatint; F. ni;':ri^'ies « 
Fhyllr'treta punctulata (Mar sham) 
See Fcthcr':rid..-e and Thomas (^Ij) u:ider P. atra (F.) on P-go 55. 
Fhyllotreta sinuata (Redt.) 
This flea beetle can be es^O'^cially in.iurious to mustard. Ducting 
with derris mixtures c^ntainin?; O.5 percent '■f rotehnne, and spraying 
with .suspensi'">ns of 1:5,000 rotenone content in the laboratory, killed 
the insects in a short time. Aft<-'r a field test in a kitchen gr^rden in 
Batavia, the treated plots were noticeably better than the untreated, 
but were not cntirelv^ free from attack, Froba.blyithis is to be ascribed 
to the rojinilpr watering of the plants, by which means the derris powder 
was washed off; then reinf est^ti-m occurred from the control plots,-- 
V^.n der Vech (Uoi) in IO36, 
Fhyllotreta undulata Kutsch 
See Fcth(-rbrid:-:e and Thomas ( 317 ) under F. atra (F. ) on page 55. 
Blunck and Meyer ij^j,) in IO32 report i-'d derris powder and Folvo 
to be effective for combating this species. 
