264 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
artificial conditions; these must probably be reckoned as per- 
manent additions to our insect fauna. 
Considered from an economic point of view, eight introduced 
species are to be regarded as noxious or at least undesirable impor- 
tations, viz., the European Earwig, European Mole-cricket, 
Asiatic Cave-cri.cket, and five species of Cockroaches. 
Injuries by Locusts and other Orthoptera in 
New England. 
Three native species of Locusts (Melanoplus m. atlanis, M. fe- 
mur-rubrum, Camnula pellucida) have in times past done severe 
damage and are always destructive; three others (Melanoplus 
bivittatus,^ Encoptolophus sordidus, Orphulella speciosa) do much 
damage annually which is not always readily appreciable, and 
are potentially dangerous; two Field-crickets (Gryllus assimilis, 
Nemohius fasciatus) also belong in this last group. The injuries 
caused by Tree-crickets (of which three species are abundant) 
are perhaps offset to a considerable degree by their destruction of 
aphids. The Tettigoniidae (Katydids, Long-horned Grasshop- 
pers, etc.) seem not to be noticeably injurious except possibly the 
three commonest species of Bush-katydids (Scudderia) when 
occurring in the vicinity of cranberry bogs. The Walking-stick, 
Diapheromera femorata, has been reported at times as severely 
injurious elsewhere in limited areas, but it is rarely other than a 
scarce insect in New England. 
While much damage in the aggregate is done annually in New 
England by Locusts, severe outbreaks are usually local in char- 
acter and of comparatively limited extent. They show a tend- 
ency to recur in the same district at irregular intervals of several 
years. This is doubtless due to specially favorable natural condi- 
tions of soil and climate, a well-drained sandy loam and several 
dry seasons generally being necessary to develop serious condi- 
tions. Southwestern Maine, southern New Hampshire, certain 
counties in Vermont and Massachusetts, but especiallj^ the sandy 
intervales of the Merrimack valley in central New Hampshire, 
^ An outbreak of this species at Dummerston, Vt., in 1915, 1916, and 1917, 
was checked in the last year to a large degree by a parasitic thread-worm, as 
many as 40 worms sometimes infesting u single Locust. 
