- 24 - 
Corythucha ma rmor ata Uhl, a chrysanthemum laqebug 
McDaniel (_58) in 1934 reported that a good kill of this lacebug on 
chrysanthemum can be obtained with either a pyre thrum or a derris prepara- 
tion by following the recommendations of the maker." 
( El a smo gna thu s ) Diplogom phus hewitti (Dist. ), a pepper lacebug 
Van der Vecht (89_) in 1935 reported that this lacebug on pepper 
■was controlled effectively only with contact insecticides, among which 
tobacco extract is more commonly used in West Borneo. The too? ceo extract 
is frequently mixed with an extract of the roots of derris, which is Cul- 
tivated nearby for this purpose. Unsatisfactory spraying tests with 
derris root extracts have been made, probably because the extracts had 
a very low content of rotenone. In 1936 Van der Vecht reported (90) 
that this bug on black pepper may be killed by spraying with derris, 
Leptobyrsa rhododendri Horv., a rhododendron bug 
Wilson (99) in 1938 reported that this rhododendron bug is con- 
trolled by means of a reliable contact spray, e. g., nicotine-soap, derrre, 
or white-oil emulsion, which should be applied about mid-June and- again in 
mid-July to the underside of the leaves to destroy the immature stages. 
Two applications are desirable, owing to the protracted period- of hatching. 
Stephanitis pyri ( F. ) 
The Etablissements F.otenia in 1938 stated in a letter to R. C. 
Roark that a product manufactured by them, containing 0.72 percent of 
rotenone with talc as a diluent, kills (Tingis) Stephan itis pyr i on 
pear trees. 
Stepha nitis rhododendri Horv., the rhododendron lacebug 
Sh (77) in 1936 reported the following results from tests of derris: 
: Mortality 
Material : Larvae : Adults 
Percent Percent 
Derris dust --------- ----- - 19 73 
Derris spray- -..___ 77 100 
Derris spray +0.5 percent soap - - - - 100 100 
Derris spray + 1 percent soap ----- 100 100 
Derris spray + 2 percent soap ----- 100 100 
Van G-undia (88) in 1936 reported that a rotenorc dust containing aboi 
30 percent of sulfur in the form of fused bentonite- sulfur (which aids as 
a sticker for the rotenone and also acts as an activator) controls the 
lacefly on rhododendron. 
Unidentified species of Hemiptera 
Rotenone spray 1:5,000, plus 0.1 percent Agral I, gave unsatisfactory 
control of "Wantsen" on string beans. — h ; ageningen Plantenziektenkundige 
Dicnst (91) i:i IE 34. 
