- 19 - 
Altic? srp, 
Hampp (175) in I937 reported that flra beetles of the gr-nera Chaeton- 
neina, P3yllicc.es . and Altica are among thr wors* pppts of hops in Bavaria, 
cspocially in warm, sunny sitiia.tions. In ppring tho in.iury to the shoots, 
usually most sf^vrri^' in May, retards their grov;th, wca'-ccns tho plants, and 
reduces tho crop. Thn srcond- sumricr attacl<- impairs the appearance ?^nd 
quality of the infloroscances. The "beetles wer? particularly a"bundant in 
iP2g, in I93U (which was .^xtromel;' hot and dry), and in 1^3^. Some vari- 
eties of hops are more attacked than others; ^.g. , those that grow rapidly 
when young overcome tho effect of the injury most readily. Sine"; 1*^"'26 U5 
different ins^ cticidrs have been tested in 71 exprriments. Hand du'st^-'rs 
andkiapsack sprayers were used. On an average, 60 minutes were rec^xired 
to dust 7,000 hop vines and 70 minutes to spray them with 22 gallons of 
spray. The effect was best judged after ^n i-itrrval of 72 hou>rs. In th^ 
dusting tests, derris insecticides invariably proved absolutely reliable 
anrd were di^^tinsiuished by rapid and eff'^cti'^-e action. Pyrethrum vsis al- 
ways less efficient, end though goer, result? vere obtained vrith 22 pou-^.ds 
per ],000 vi'ies, it ig not advocated, -iicoti -.p acted o'lickly, but renuired 
a high air humidity, and many btetl^s r'-cover^ d. Ar-senicels act'=d slovdy 
but were effective if the weather v/as cor.tiriuously fine. The silicic 9cid 
powder, Naaki , '.\ras merely a repellent. In the spraying tects, derris ^.n^ 
nicotine h?d eood killing power, v;hile fi^it of pyrethru-i was poor. Dij^t*:, 
however, are nor' s?itisfactory, prom t ari'i^.licrtion being essential. 
Aphthona ap. 
Sensitive to derri^i dust. — DeBu'isy et al. (6_l) a.'r" van der Laan 
(252) in 1936. 
Aspidomorpha miliaris ( F . ) 
The larvae of this b'^etl'-- were used a'^ te«;t insects for d-^termin- 
ing the insecticidal value of speci lens of derris by Corbett, entomologist 
of the Federr^ted Malay States Department of Agriculture (22U) in 103"^. 
They were also us'^d by the Federated Malay States Deoartm-nt of Agric-)lture 
( 123 ) in 193^ i'- testing the ins.- cticidal value of Derris elliptic?^ and 
D» malacc'.nsis . 
Killer (2.^6), of the Feder^-'ted Malay St^tns D.-^-^artment cf Agric^atnre^ 
in 1975 reported results of spraying ^ind immersion tests against A. mili - 
ar is which indicated that the insecticidal properties of the three kinds 
of derris tested were about the same. He concluded that the rotf^none con- 
tent is not necessarily a reliable index to the toric valu^ of derris root, 
Rotenone, deguelin, and toxicarol \^'rr^ only moderat'l toxic to the in- 
sects used in the toBts, The aqueous solr.tions of derris root or crushed, 
freshly harvested roots wore toxic to larvae of A. miliaris without actual 
contact, indicating thrt derris nay yield a volatile toxic substance. 
Fluids obtained from derris by atea.i distillation were also toxic to larvae 
of the sp ^le sp cieg vrhen imners'^d therein, killing 12 Tjercent of A, mili - 
.Qjrls. The indications arr that derris may affect the nervous syst.-'m of 
insects through the integument, and may also act as a repellent. 
