-630- 
SUMMA.RY 01 INSECT CONDITIONS IN HAWAII FOR 1931 
0. H. Swezey 
The sugarcane leafhopper ( Pp rid n si el la sacchariclda Kirk.) has been 
well controlled "by natural enemies. On one plantation on the Island of 
Hawaii there was an outbreak covering about 200 a-.res in early summer, 
but natural enemies, chiefly, egg parasites, the egg-sucking bug Cyrtorhi- 
nus mundulus Bredd. . and spiders, soon gained control. 
No unusual infestation of the sugarcane weevil borer ( Rhabdocnemis 
obscura Boisd.) has been noted. There is very satisfactory control by 
the Hew Guinea tachinid Ceromasia sphenopho ri Vill. The better control 
of rats in the sugarcane fields has lessened injury, for where cane is 
gnawed into by rats, the female borer more readily lays eggs in the cane, 
Isesulting in increased infestation. 
The nutgrass armyworm ( Spodoptera mauritia Bdv.) developed unusually 
bad outbreaks in several localities where sugarcane fields had been in- 
fested 'with 'nut grass,.,., especially -on the island of Maui. Usually this 
pest is— controlled by parasi±-es r but -poisoning-had to be resorted to on 
a large scale. .- 
In several localities in one plantation the grubs of the Asiatic 1 
beetle ( Anomala o ri en t a lis Wat e rh . ) caused enough injury t t the roots of ' 
sugarcane to affect the yield. In most of the infested area, however, 
grubs have not been numerous enough to be detrimental. This pest is 
usually controlled by Scolia manilae Ashm., but in some cases, in fields 
of heavy infestation, the wasps "ere unable to gain access to the grubs, 
and in these areas some damage was done. Afterward, Scolia gained ac- 
cess and the grub infestations were controlled. 
The Chinese grasshopper ( Qx.ya chinensis Thunb.) has spread more widely 
on the Islands of Maui and Hawaii and gives indication of becoming a sugar- 
can pest of importance, as shown \>y the ragged leaves of fields bordering 
infested grass fields or grassy roadways. An egi; parasite ( Scflio sp. in- 
troduced from the Malay States is being reared for distribution. 
The pink sugarcane mealybug ( Trionymu s sac char i Ckll.). is very general- 
ly pre sent i in all sugarcane fields, but without causing particular injury. 
A parasite (Anagyrus sp.) has recently been introduced from the Philip- 
pines and has become established in a few localities. A ladybeetle 
( Pullus sp.) which specially preys on this mealybug, also introduced from 
the Philippines, is being reared and distributed and "111 no doubt help 
to ameliorate the mealybug conditions. 
