INSECTS INJURIOUS TO AGRICULTURE IN JAPAN 79 



for the completion of the life cycle in the summer and six weeks in 

 the winter. The eggs are laid in masses of 200 or more on the upper 

 .sides of the leaves. The newly hatched larvae feed upon the epi- 

 dermis, but shortly inclose a number of leaves in the light web and 

 feed upon these and the buds. As development proceeds the web 

 is enlarged, and often every shoot in the garden is inclosed. Pupa- 

 tion takes place within a folded leaf. Control is effected by the 

 collection of egg masses during the early winter and the removal of 

 all twisted leaves containing larvae and pupae. The first method 

 of control is the most effective, and the second must be undertaken 

 in the early stages of the attack when only relatively few of the 

 shoots are involved. This species is recorded by H. C. Woodworth 

 as a minor pest of cotton in the Philippines. 



Another tortricid which occasionally causes severe injury is 

 Adoxophyes fas data. Its life history is nearly identical with that 

 given for the preceding species. 



The red coffee borer, Zeuzera cofeae (172), is recorded from 

 Taiwan upon tea, but only a little information is available regard- 

 ing its habits. Upon other hosts the larvae bore in the trunk and 

 branches, and pupation occurs in a cell near the surface of the bark. 

 According to Shiraki this is the species referred to in early literature 

 as Z. pyrina. 



The tea leaf roller, Gracilaria theaevora (SI, 175), is a common 

 pest in Taiwan and is recorded also from Japan. It is one of the 

 most injurious of the insects attacking tea in Java. The eggs are 

 laid singly upon the leaves, and the young larvae mine the leaf 

 tissue. When partially grown they emerge from the mine and roll 

 the leaves, after which feeding is external. Pupation occurs in a 

 cocoon on the lower surface of the leaf. 



The geometrid Biston marginata (172) is found most commonly 

 in the field during April, and in the northern part of Taiwan com- 

 plete defoliation of entire plantations often occurs at that season. 

 Though tea is extensively attacked, the preferred food plant is acacia. 

 Because of the size of the larvae only a few are required to strip 

 a bush entirely of its foliage. There is one brood each year, and the 

 winter is passed in the pupal stage in the soil. The eggs are laid 

 en masse upon the trunk or branches during March, and the larvae 

 feed until May. Control is easily effected by the destruction of the 

 adult moths and the egg clusters during the early spring. 



In Japan the most common of the geometrids is Jankowskia fus- 

 caria (SO), which is at times a serious pest. The eggs of this and 

 certain other species of the family are laid under the bark of pine 

 trees adjoining the tea gardens, and the larvae migrate to the tea 

 bushes. For control, spraying against the young larvae with insect 

 powder and soap solution is recommended. 



The two species of Psychidae listed, Glania variegata and G. de- 

 structor (169, 172), are widely distributed in Taiwan and at times 

 appear in great abundance, the entire crop in some cases being lost. 

 G. variegata occurs in Japan also. Its preferred host plant, aside 

 from tea, is the acacia. There is one brood a year, and the adults 

 are found only in the early spring. From 40 to 150 eggs are laid 

 by the wingless female in its case, and these hatch in from two to 

 three weeks. The larval case is composed largely of bits of leaves, 



