HEMIPTERA — THRIPSINA. 



1:2 



been carefully studied. The most troublesome species are the pear thrips, 

 Physothrips pyri, the onion thrips, Thrips tabaci, the greenhouse thrips 

 Heliothrips haemorrhoidalis, the orange thrips Physothrips citri. and the 

 grass thrips Fraakliniella tritici. A number of species are known to feed on 

 other insects. 



SYNOPSIS OF GENERA. 



Sercothrips: adbomen with a silky lustre due to covering of extremely 

 fine hairs. 



Physothrips: abdomen with saw-like ovipositor, and antennae eight joinetd 

 Heliothrips and Echinothrips: body reticulate, the latter with prothorax 

 as long as head. Limothrips: tibiae with a pair of stout spines near the tip. 

 Odontothrips and Frankiinelia: with prominent spines at front angles of 

 prothorax, the latter with tooth at end of front tibiae. 



Trichothrips: abdomen without saw-like ovipositor and head about as wide 

 as long. Haplothrips: antennae seven jointed. 



Thrips: antennae seven jointed. Parenothrips: body reticulate. 



/^olothrips: antennae nine jointed. Orothrips: wings with dark cross 

 bands. Erythrothrips: wings with longitudinal bands. Ankothrips: last four 

 abdominal segments not closely united. 



Liothrlps. Megalothrips: head more than twice as long as wide. Hoplo- 

 thrips: with tooth at inner side of front femora. Cephalothrips and Crypto- 

 thrips: wings rudimentary, the latter with spine bearing warts on cheeks. 

 Phloeothrips: cheeks with spine bearing warts. 



Synopsis: — Moulton, U. S. Ent. Tech. Bulletin 21, Jones, ibid. 23. 



Figure 310. Scolothrips sexmaculatup 

 Feeds on Red spider. 



I llri 



Figure 309 Heliothrips fasciatus. 



/^OLIOTHRlPID/e. 

 /Eolothrips fasciatus Linn. kuwanaii Moul. 



iongiceps Cra. 



nasturtil Jones. 



