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SUMMARY IN ENGLISH. 
The two-=coloured Coconut leaf-beetle (Bronthispa (Froggatti SHARP ?)). 
This beetle has not previously been described or mentioned by Dutch 
Entomologists. Hispid beetles, mentioned by KONINGSBERGER and KEUCHENIUS 
belong to other species. However the two-coloured leaf-beetle or a very 
closely allied species has been mentioned by FROGGATT. In New Britain and 
the Solomon Islands this beetle has been the cause of great anxiety and in one 
case, mentioned by FROGGATT, fully 50000 young plants have been ravaged. 
On the West Coast of Sumatra (at Padang) and in West Java, only 
young plants (up to 4 years in age), are damaged by this pest. | have 
never observed important damage to older trees. In the island’ of Celebes 
important damage to older trees has been caused by a Hispid beetle, but 
of another species. In one case damage by our present beetle also may 
have been done, but this case is not yet quite clear. 
The development of the beetles takes place between the folds of the 
opening fronds, where the beetles and larvae feed upon the leaf tissue, 
leaving alone the veins running to the top of the leaf, eating the cross 
veins in contrast with the caterpillars of Brachartona, which do not eat the 
cross veins, so the damage of the latter is window shaped. As a result 
of the damage the leaves show reddish brown and later on black spots 
and in case the insects are numerous the leaf turns totally brown and in 
many cases the young shoots decay and the plant dies. 
The author believes, that the damage caused by the beetle and larvae 
is much increased by a fungus Pestalozzia palmarum which seems to 
penetrate the leave tissue at the wounds caused by the beetles or larvae. 
The beetles are 6,6 to 7,9 mM long, without the antennae. Seen 
without a lens the beetle appears to be black, excluding head and breast 
which are orange brown. Further details are given in the text. The sexual 
differences may be mentioned here. Both male and female are provided 
with a sort of frontal horn, which is a frontal extension of the head. In 
the male this horn is rather long and flat, with the female it is compressed, 
pointed and smaller. Furthermore the distal edge of the last ventral segment 
is incised with both sexes but much more with the male than with the female. 
The eggs are 1,65 to 1,74 mM in length and 0,7 mM in width. They are 
coloured leather brown, but are partly covered with excrements of the beetle. 
The eggs emerge after 7 to 10 days, generally after 8 to 9 days. The 
young larva is very small, about 2 mM and white. It starts feeding imme- 
diately. Figures about the growth of several larvae are given. The larval 
stage lasts 31 to 38 days. The fuil grown larva is dirty white or yellow, they 
