4 BULLETIN 256/ "IT. S. DEPARTMENT OF AGRICULTURE. 



grossly infested in 1911 that 57 per cent of all the mature fruit was 

 ruined. This was determined by actual count made at picking time. 

 Many undeveloped, badly chewed oranges on the trees and the usual 

 dried remains of other riddled fruits on the ground were not taken 

 into account in this examination. These trees, which should have 

 produced, at the very least, 2 boxes of oranges each, averaged only 

 about 7 sound oranges per tree. In 1912 the injury was again very 

 great in this orchard. A large amount of fruit was chewed and 

 destroyed while still small, and the average number of oranges was 

 but 9 per tree after all dropping had ceased and the fruit had matured. 



It should be mentioned that, to the present time, the most severely 

 damaged orchards are generally those in which the trees are 10 years 

 of age or younger, although several of the older orchards suffered 

 greater injury in 1912 than in any previous season. 



Injury to Valencia oranges. — Examination of all the fruit on several 

 trees in each of 15 Valencia orange groves showed this variety quite as 

 susceptible to attack by katydids as the various navel types, the 

 percentage of injury being practically the same in both. 



Injury to foliage (PI. Ill, fig. 1). — The fork-tailed katydid, as well as 

 the angular-winged katydid, feeds during its entire life upon the leaves 

 and stems of orange trees. It selects by preference the new, tender 

 growth, filling the leaves with holes and often completely destroying 

 the stems. The injury to foliage has not been serious except on trees 

 where the nymphs were unusually numerous. 



FOOD PLANTS. 



Under the conditions prevailing in the San Joaquin Valley citrus 

 area, the fork-tailed katydid feeds almost exclusively upon the sweet 

 oranges, where at all times the food supply is abundant and attractive. 

 It has not been taken upon any other variety of citrus. Weeds are 

 rarely allowed to grow in the orchards and, except in early spring, 

 do not flourish on the unirrigated lands surrounding them. The 

 insect has not in a single instance been found upon native weeds. 



On one occasion, in October, 1911, the senior author heard a male of 

 Scudderiafurcata stridulating in a patch of string beans. Examination 

 of the plants disclosed two adult females, and a bean leaf was found 

 which contained two eggs. The following month he found eggs of the 

 species in the leaves of apple and peach trees growing near orange 

 trees. The insect was reported to the writers by an orchardist as 

 injuring grapevines on his place. This report was verified and the 

 injury found upon both leaves and berries. 



Other writers have reported the insect as occurring upon "weeds," 

 "coarse grasses," "thickets," "hedges," etc. Its food plants un- 

 doubtedly comprise widely different species in various sections of the 

 United States. Under the name Scudderia curvicauda (De Geer) it 



