42 CIRCULAR 16 8, U. S. DEPAET^IEXT OF AGRICULTURE 



in large masses, such as is characteristic of /. purchasi (62. 168). 

 I. seycheUarum in Japan is heavily parasitized by the agromyzid fly 

 Cryptocho.ttum grandicome Bondani which also attacks D/^oskha 

 corpidthta but has never been taken as a parasite of /. purchasi. 



Three species of leaf hoppers are at times found in some numbers 

 upon citrus trees in Taiwan. Tettigordella viridis lavs its eggs in 

 the branches of these as well as other fruit trees, and Tartessus fer- 

 rugineus. which occurs throughout Japan. Taiwan, and China, is at 

 times quite abundant, being also found upon the foliage of fig trees. 



Among the aphids Toxoptera aurantii causes considerable injury 

 to citrus during the early part of the season, both in Japan and in 

 Taiwan, and causes the typical curling of the young and tender 

 foliage. The injury is accompanied by a consequent retardation of 

 growth, this being in part due to the development of sooty-mold 

 fungus in the honey dew. Aphis t a rarest also becomes very injurious 

 at times in Taiwan. 



The chermid Diapliorina eitri [13-3. 169) at times becomes very 

 abundant in Taiwan and causes extensive injury to citrus trees. 

 Its distribution extends to south China, the Malay Peninsula. Java. 

 and India. The number of generations a year is unknown, though 

 the nymphs are most abundant during May and June and September 

 and October. The eggs are laid at the margin of the younger 

 leaves. Both nymphs and adults are markedly gregarious in 

 habit. Very extensive feeding takes place upon the under surfaces 

 of the leaves and smaller twigs, the former turning brown, and, 

 in the case of heavy infestations, withering. 



According to information furnished by Doctor Kuwana. the citrus 

 rust mite. PhyUocoptes [Eriophyes) oJeivorus. was first observed 

 in Japan in 1903. though its identification was not definitely estab- 

 lished until 1909. It now covers the entire citrus-producing areas of 

 Japan and Taiwan, and is also known from China, the Philippine 

 Islands, and the Straits Settlements. In Honshu it is most abund- 

 ant in Shizuoka Prefecture, and the injury produced is much more 

 serious during periods of dry weather. "When the characteristic 

 injury to fruits by this mite was first found it was known locally 

 as " zohibyo." or elephant skin, from the similarity in appearance 

 to the skin of that animal, and later in Taiwan it was called aki- 

 yald (red ware) from its resemblance to a certain type of porcelain. 

 At Xagasaki certain women fruit venders specialize in the handling 

 of fruit injured by this mite, and although the price is lower the 

 claim is made that the flavor is superior to that of the normal fruit. 

 Control may be effected by the use of lime-sulphur spray. 



MISCELLANEOUS TROPICAL AND SUBTROPICAL FRUIT INSECTS 



OLIVE INSECTS 



A recently discovered pest of olive in central and southwestern 

 Japan is the curculionid Hylohius perforatus. According to 

 Poutiers (157) olive trees were very severely atacked when an 

 attempt was made to plant them in orchards at Takamatsu and 

 other places. The species constructs galleries which widen out from 

 the inner bark to the sapwood. resulting at times in the complete 



