Insect Enemies op Greenhouse and Ornamental Plants 5 



It has been found on the white ash (Fraxinus americana) , the 

 green ash (F. lanceolata), the red ash [F. pennsylvanica (pubes- 

 cens)], and the English ash (F. excelsior Var. pendula). 



When present in large numbers the foliage of ash trees is 

 disfigured considerably by the adults and nymphs sucking out the 

 plant juices, causing numerous white spots to appear on the upper 

 leaf surfaces. The bugs feed singly on the under surface, and are 

 quite active, moving as a rule quite rapidly when disturbed. In 

 severe infestations the leaves become dry and somewhat curled. This 

 is especially true of young tender leaves which have been addition- 

 ally injured by egg deposition. 



Eggs hatch in from ten days to two weeks and there are five 

 nymphal stages, each requiring from four to eight days, the average 

 length of time consumed from egg to adult being about five weeks. 

 Adults are about 5mm. long and 2.5mm. wide and those of the 

 first brood are usually plentiful about the middle of July at New 

 Brunswick, those of the second brood appearing the latter part of 

 August. In the more northern parts of New Jersey, they appear 

 from one to two weeks later. On account of the somewhat extended 

 oviposition period, it is quite possible to find later stage nymphs and 

 adults present at the same time. In the latitude of New Brunswick, 

 N. J., there are two generations, the first adults appearing about 

 the latter part of May or the first of June. 



The eggs, which are 0.4 mm. long and 0.14 mm. wide, trans- 

 lucent, flask-shaped, broad and rounded at the posterior ends, are 

 deposited in the mid-ribs on the under-sides of young tender leaves. 

 The whitish, circular rim of the egg cap projects out a slight dis- 

 tance but is effectively hidden by the pubescence on the mid-rib. 

 Where many eggs are deposited in a leaf, a curling and distortion 

 takes place. As far as is known, no attempts have been made in 

 New Jersey to control this species by the application of insecticides. 



The Rhododendron Lace Bug 



Leptobyrsa rhododendri Ilorv. 6 (Fig. 4, 5, 6) 



This species was first described by Iiorvath as Stephanitis rho- 

 dodendri in 1905 7 and later by Heidemann 8 as Leptobyrsa explav- 

 ata, under which name it is usually considered by American collec- 

 tors. It has a wide distribution in the East and occurs at a number 

 of places throughout New Jersey. It is undoubtedly a native 

 American species which has been introduced into Europe on rho- 



6This account has been drawn from an unpublished paper by Dicker- 

 son, E. L., and from Crosby, C. R., and Hadley, C. H., 1915. The 



rhododendron lace bug {Leptobyrsa Explanata) . In Jour. Econ. Ent., 

 v. 8, p. 409. 



7Horvath, G., 1905. Tingitida? Novaeet Minus Cognitse e Regional 

 Paleartica. In Ann. Mus. Hung., v. 3, p. 556. 



8Heiden.ann, O., ioo8. Two New Species of North American Tingitidae. 

 In Proc. Ent. Soc. Wash., i. io, p. 103-108. 



