New York Agricultural Experiment Station. 317 



the nourishment of the plant and cause serious harm. Some forms 

 prey on other insects. 



The species under discussion was described by Say 13 in 1831, 

 who named the insect Capsus invitus without giving its host-plant, 

 which was apparently unknown to him. In 1878 Uhler 14 redescribed 

 the species from one of Say's type specimens, placing it in the 

 genus Lygus, and the insect is now known to naturalists as Lygus 

 invitus Say. It has not so far received a popular name, but on 

 account of its injurious habits and importance as a fruit pest the sug- 

 gestion is made that it be popularly called the false tarnished plant- 

 bug, which seems to be appropriate because of its great similarity 

 to a closely-related and well-known form, the destructive tarnished 

 plant-bug (Lygus pratensis L.) 



DESCRIPTION OF LIFE STAGES. 



. Egg. — The egg is smooth and cylindrical as represented in Fig. 19. It measures about 

 .8 mm. in length and .21 mm. in width. It is described in detail as follows: cylindrical; 

 elongated; base rather bluntly rounded; lateral margins slightly swollen, 

 strongly curved near the apex on one side, opposite margin strongly in- 

 dented near apex to form a broad neck, which is surmounted by a 

 narrow collar somewhat wider than the neck; apex of egg flat, ellipti- 

 cal in cross section. Chorion, clear; translucent; very delicate; coarsely 

 punctured. Cap, coarsely punctured; whitish; opaque. Collar, whitish; 



p IG iq . opaque. Color, yellowish white, trans- 



•g GG lucent. 15 



Nymph. — The nymphs are small 

 pale creatures in the first two stages and green in 

 the third, fourth and fifth instars. In all stages 

 they have the same general form which changes 

 only in size and with the appearance of wing pads 

 in the last three stages. 16 The measurements of 

 the several instars are as follows: 1st instar, .85 mm. 

 long — .37 mm. wide; 2nd instar, 1.18 mm. long — 

 .42 mm. wide; 3rd instar, 2-2.5 mm. long — 1.03 mm. 



wide; \th instar, 3-3.25 mm. long — 1.3 mm. wide; Fig. 20. First Stage Ntmph. 



1th instar, AAA mm. long — 1.5 mm. wide. 

 The technical description of each of the nymphal stages follows: 

 First Instar. — Body, small; ovate-oblong; lateral margins narrowest behind the eyes, 

 gradually widening with minor indentations to the fourth abdominal segment. Abdo- 

 men, pyriform. Head, large; triangular; broadly rounded at the apex, narrowing 

 behind the eyes; eyes compound; integument smooth, with numerous small hairs 



13 Ent. of N. Am. 1 : 345. 1891. Le Conte ed. < 



u Proc. Bost. Soc. Nat. Hist. 19:407. 1878. 



"The egg of pratensis differs chiefly in size. It is slightly larger and the chorion 



is more delicately sculptured. Length, about 1.02 mm.; width, about .27mm. 

 "The nymphs of pratensis are small yellowish creatures in the first two stages. 



The larvae of the third, fourth and fifth stages are greenish in color, and may 



be distinguished from the young forms of invitus by five more or less distinct 



black spots upon the back. 



/" 



