- 95 - 
Oeutorhyr.chus gulcicollis (Fay'-c.) . 
This pept on cauliflov/or was killed by" a. product containing 12 p<=rcent 
of powdered Loncho carpus nicou root (of 6 percent rotenone contf^nt and 88 
percent of talcu"!, according to a letter from Etablissements Rotenia, of 
Antviffrp, BelgiuTn, to R. C. Soark in 1938, 
Chalcodermug aoneus Boh. , the covrpoa curculio 
Arant (_12.) in 1^3^ reported tests of insecticides against the co\^rpea 
curculio. A suitable method of testing the efficiency of insecticides 
against the cowpea cixrculio consisted in confining the insect for 6 to 8 
hours in a Petri diph containing a film of the powdered insecticide, then 
transferring the insect to food, and ma.king regular observations to deter- 
mine the percentage of kill. Large numbers of the beetles were used and 
tests of the various insecticides were conducted sinultaneously, Derris 
{k percent of rotenone), derris with talc, find derris vrith sulfur were 
relati'^'-el.' incff cctiv.-. 
Arant (20 ) later in ig^S further reported on the control of the cowpea 
curculio, in Alabama. This is one of the 'ne,1or insect pests in Alabana and 
other Gulf Coast States. Among the inf?ecticidr.l dusts tested during I93I- 
35 were derris plus talc, and derris plus sulfur (each containing 2 percent' 
of rotenone), and Florotc, which is defined as follows* -^ commercial dust, 
containing rotenone, 5 percent; pyrethrins, 1 percent; nicotine, 1 percent; 
residual deposit of rotenc e, 2,5 percent; and inert materials, 90.5 per- 
cent. Later samples contained a lovrer percentage of active ingredients. 
The derris dusts a.nd Florote caused very little or no burning but gave 
negative or very low positive percentages of control. The author's con- 
clusions are as follows! 
According to result? of field experiments in I93I-35 
calcium arsenate is significantly more efficient than any 
other insecticide tried for controlling the cowpea curculio; 
sodium fluosiliC'-'to is next in efficiency. The percentages 
of control for the various materials used in the experiments 
were as follows* Calcium arsenate, 7'^«53* sodium fluosilicate, 
67.11; magnesium arsenate 6l.57; acid lead arsenate, 50.93» 
barium fluosilicate, Uo.Ob; cryolite, 26.22; pyrethrum, 28,68; 
riorote, 3*71; derris, -2.97 percent. Both calcium arsenate a>,nd 
acid lepd arsenate caused severe burning of foliage, 
Florote w^^s applied eight times; the derris mixture? five times each. 
A derris-kaolin dust (l percent of rotenone) vfas applied seven times 
in the field during the T)eriod June 29 to August 25, ^hr poas were picked 
four times in the p-'riod August 5' to September 27. The degree of ins ct 
control in the' fir?t picking was Uo.5 percent and for four pickings 7"^. 3 
percent. — G-eorgia Eyprrimpnt Station (I'^U) in I93S. 
