Apr. 1, 1918 Stoneflies Injurious to Vegetation 41 



Labium. — Rather simple. Glossae small and tapering; paraglossae larger, thumb- 

 like; both provided with long and short spines. Palpi three- jointed ; a distinct 

 tactile surface on the inner side of the tip, covered with short spines. 



NYMPH 



The nymphal mouth parts are practically identical with those of the adult, with 

 the exception of the mandibles. The teeth of the latter, particularly the left man- 

 dible, are somewhat blunter, and the grinding edge of the left mandible is provided 

 with a row of stout spines. 



OTHER SPECIES 



On May 31, 191 5, a trip was taken into the mountains back of Wenat- 

 chee, and there, in the pine woods at an elevation of 3,000 feet, two 

 distinct species of stoneflies were found feeding on the native vegetation 

 along the banks of a swiftly flowing stream. These species have been 

 identified by Mr. Banks as Taeniopteryx nigripennis and T. pallida. The 

 former species was much the commonest, is smaller than T. pacifica, 

 being only 9 ram. in length, and is black. T. pallida is slightly larger, 

 and brown, with light wings. The foliage along the stream had quite 

 a ragged appearance, as these species were very numerous and feed- 

 ing voraciously. The plants affected, in the order of the preference of 

 the stoneflies for them, were the thimbleberry {Ruhus parviflorus) , alder 

 (Alnus tenuijolia), willows {Salix spp.), wild rose {Rosa sp.), serviceberry 

 {A melanchier sp.), and maple {Acer donglasii). 



The mouth parts of these species have been examined and found to 

 be very similar to those of T. pacifica. They are, of course, smaller, 

 but fully as well equipped for biting soft plant tissues. 



On April 25, 191 7, a single stonefly was observed at Salem, Oreg., 

 feeding on young cherry leaves. This specimen was captured, and has 

 been determined as Taeniopteryx sp. by Mr. A. N. Caudell, of the Bureau 

 of Entomology. A search failed to reveal any more specimens. 



One may conclude from these observations that a study of the habits 

 of stoneflies in other parts of the country, particularly those of the 

 genus Taeniopteryx, will bring to light other plant-feeding and, hence, 

 potentially injurious species. 



