632 PROCEEDINGS OF THE TIIIKD ENTOMOLOGICAL MEETING 



No. 3. — Toxopfera citrifolia, Maki. (Kamikan-Aburamushi.) 

 This is one of tlie most common pests of tlie orange-tree, and it is also 

 found on several roses, or very_ rarely on the tea-plant, but its injuries 

 are very slight. This pest usually occurs in the Northern part of For - 

 mosa, but it is not recorded from the South. 



Only one control-measure is recommended by us, i.e., the spraying 

 of contact poisons, and this is practised at the time that the young 

 leaves are plentiful or that the buds are coming forth. 



No. 4. — Ceroplasfes ceriferus, Andrs. {Tsuno-Romushi.) 

 This giant Scale-insect is rather common throughout the whole 

 Island, but not so abundant that the plants suffer from it. This inju- 

 rious insect attacks the twigs or trunks or rarely the leaves of the 

 tea-plant, orange-tree, mulberry-tree, and Eugenia malaccensis, L. 



No. 5. — Cero])Jc(stes flofidensis, Comst. {Mikan-Bokaigaramuslii.) 

 This is not common in the Island of Formosa, but we can find it 

 from May to July in Northern Formosa or in September to October in 

 the South. It is one of the rare pests of the tea-plant, and is sometimes 

 found on the twigs of orange, pear and mango. 



No. 6. — Cero2)lasfes rubens, Mask. {Momoiro-Eokaigaramuslii.) 

 This species is less common in Formosa than ceriferus, but rather 

 more familiar to us than the preceding Scale-insect. We have found 

 several host-plants, of which tea, camphor, orange and Psidium guyava 

 are imjDortant plants in Formosa. I do not mean to state that these 

 plants are destroyed by this insect. 



The three Scale-insects described above are rather resistant to spray- 

 ing with contact insecticides, but fumigation with cyanide acid gas is 

 recommended. The latter measure is only practised for destruction 

 of the scales attached to the young shoots. 



No. 7. — Lecanium liemisfhcericum, Targ. {Mikcm-Tamakaigaram- 

 usJii.) 

 This is the rarest species of tea-plant Scale-insects, and its injuries 

 are very slight although the insect attacks the young twigs. Of its 

 other host-plants the orange-tree is well known. The larvae are usually 

 found in April or May and the imagines in September. The scarcity of 

 hemisj)li(jericum is mainly due to the fact that a certain species of Chal- 

 cidid occurs on it. 



No. 8.— Chionaspis thece, Mask. {Cha-no-Nagakaigaramushi.) 

 This CJiionaspis occurs throughout the Island, and is very common 

 and abundant in the Northern parts. It is only found on the upper 



