58 CIRCULAR 16 8, U. S. DEPARTMENT OF AGRICULTURE 



Other insect species of less consequence than those above mentioned 

 are Pyrausta nubilalis, Pestinophora gossypiella, Ghloridea dipsacea, 

 Acronycta consanguis, Phassus (Hepialis) excrescens, Geisha dis- 

 tinctissima, Rhinonchws pericarpius, Mordellistena cannabisi, Tetti- 

 goniella fermginea var. apricalis, and Ricania japonica. 



INDIGO INSECTS 



The curculionid Lixus wipressiventris (95) is a common pest of 

 indigo in Japan. There are three broods each year, the winter being 

 passed in the egg stage on weeds in the fields. The eggs are laid in 

 the stem of the plant in small groups and hatch in about one week. 

 The larvae bore into the stem, preventing its development, and reach 

 maturity in three weeks. The adults of the second brood feed upon 

 the foliage. 



Other pests recorded upon indigo are the chrysomelids Grep- 

 idodera chloris and Monolepta dichfoa, and the curculionid Ceu- 

 torrynchus asper, but little is known regarding them, and they are 

 of minor importance. 



RUSH INSECTS 



The use of rushes (J uncus sp.) as a material for the manufacture 

 <)f matting is very extensive in Japan, and consequently the insects 

 attacking this plant are of economic importance. The recently de- 

 scribed sawfly Tomostethus pmcivorus (2%) often becomes very abun- 

 dant and injurious. There are two broods each year, the adults of 

 the first appearing in May, and those of the second in September. 

 The winter is passed in the larval stage in a cell in the soil. The 

 eggs are laid singly in the leaf tissue, and the young larvae feed 

 therein from 9 to 15 days, after which feeding takes place exter- 

 nally. The first brood of larvae feeds at the tips of the leaves at 

 night and rests during the day at the base of the plant, but with 

 the second brood this habit is reversed, and feeding takes place 

 during the day. Spraying when the larvae are in the early stages 

 and crop rotation are recommended as measures for control. 



COTTON AND TOBACCO INSECTS 



Cotton is grown to a considerable extent in both Chosen and 

 Taiwan, but only to a slight extent in Japan proper. In Chosen 

 cotton has been cultivated for a period of less than 20 years, and 

 the area under cultivation in 1923 was approximately 200,000 acres. 

 Practically all the information regarding the insect pests which 

 attack this crop in Chosen is given by Matsumoto (89), and Shiraki 

 (167) in Taiwan has published an extended account of the cotton 

 insects of the world, among which are a number native to that island 

 and previously unrecorded as pests of this plant. 



Tobacco is produced in central and southern Japan, Chosen, and 

 Taiwan, but only a little information is available regarding the pests 

 attacking it. 



