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THE SUGAR-CANE BORERS OF JAVA! 
By Dr. L. ZEHNTNER. 
DIATRAA STRIATALIS, SNELLEN. 
The female of Diatrewa striatalis lays about 75 eggs, always ten to 
twenty together and arranged in two rows (in the form of a zigzag), so 
that the eggs partly cover each other. The eggs are strongly flattened, 
have an elliptical form, and, as a rule, are found on the upper side of 
the leaves. Freshly laid they are greenish white or gray; afterwards 
they become orange or red. Length of an egg 1.5 to 1.8™™, breadth 
0:85 (0: Le, . 
The young caterpillars are 2 to 2.25™™ long. They go between the 
young leaves, which are not yet unfolded. There they eat off the tissue 
of the leaves in spots, so that the epidermis of one side only remains. 
The presence of the caterpillars is indicated by their excrement as well 
rT 
a 
eee a A 
Fic. 9.—Diatrea striatalis: egg masses in situ on cane, at left—naturnl size; larva, atright--enlarged 
: (after Zehntner). 
as by the damaged leaves. After having changed their skins four times, 
the larve penetrate the stalk at different places, and commence to 
tunnel in an irregular manuer. One often finds as many as ten larve 
in one stalk. During the burrowing in the stalk the larva changes the 
skin once more and thereafter transforms to the pupa, which lies as a 
rule near the surface of the stalk or between the stalk and the sheaths 
of old leaves. | 
The whole development is accomplished within the following periods: 
Development of the egg, 8 days; development of the larva. 37 to 40 
‘This article is a brief résumé of the results of some of the important and inter- 
esting studies which Dr. Zehntner has been making at the experiment station at 
Pasoeroean, Java, during the past few years. The results of his work are pub- 
lished in the numbers of the ‘‘Mededeelingen van het Proefstation ‘Oost Java,” 
from which publication the accompanying illustrations have been copied. The 
English abstract he prepared at our request.—L. O. H. 
