PLATE 20 



105 Contarinia liriodendri 0. S., tulip tree. 



201 Cecidomyia on witch-hazel. 



143 Hormaphis hamamelidis Perg., witch-hazel. 



233 Lestodiplosis cratcegifolia Felt. (This is a predaceous form, the true producer is unknown), 

 Crataegus. 



101 Hormaphis spinosus Shim., witch-hazel. 



330 Eriophyes on Nyssa. 



291 Dasyneura purpurea Felt, Joepye-weed. 



263 Lasioptera excavata Felt, Crataegus. 



239 Sackenomyia (?) viburnifolia Felt, Viburnum. 



104 Rhabdophaga salicifolia Felt, spiraea. 



[106] 



