322 Report of tjik Department of Entomology of the 



and more or less embrowned about the disk. Length to tip of hemelytra 6 mil- 

 lims. Humeral breadth, If millims." 23 



LIFE HISTORY. 



As is common to insects of this group the nymph passes through 

 five stages, attaining wings at the fifth ecdysis. The minute yellow 

 larvoe make their appearance during the period when the trees are 

 coming into blossom and until pollination 

 is completed and the young fruits are of 

 the size of filberts. The time for the 

 emergence of the insects in their maximum 

 numbers has, during the past several years, 

 been largely coincidental with the dropping 

 of the petals, but probably this will not hold 

 true under all seasonal conditions. In 1910 

 hatching of eggs occurred during the period of 

 May 3 to May 19, and in this interval the 

 trees were in full bloom on May 5, and blos- 

 soms began to drop on May 9. In 1911 and Fig. 25a.— L. pratensis, 



c L •> Adult. 



1912 pears blossomed on May 11 and 12 and 



petals began to drop on May 15. During each year nymphs of 

 the first instar were abundant at the later date, and within one week 

 the insects, with hardly an exception, had transformed to the next 

 stage. Nymphs of the second instar differ from the preceding stage 

 chiefly in size and they appear in about one week after the eggs are 

 hatched. In 1911 many of these nymphs were seen as late as 

 May 31, while in 1912 they were becoming very abundant on 

 May 22. 



At the next ecdysis the young insects become green in color while 

 the integument appears to be tougher and more horny than before. 

 The nymphs from now on are less active and remain quietly upon 

 the foliage or on the fruits for considerable periods of time. Specimens 

 reared in the laboratory completed this instar in either 6 or 7 days. 



^The adult of pratensis is a small, oval, sucking insect about one-fifth of an inch 

 in length. It differs from invitus in size, being slightly shorter, and in the 

 angular contour of the head. The prothorax is prominent and the lateral 

 margins of the wings are rounded. The color markings on the body and appen- 

 dages are distinctive of this species. The general color is yellow or greenish 

 yellow, more or less striped with dusky, while the scutellum is margined with 

 ivory. On the other hand invitus is usually brown and lacks the marginal 

 markings on the scutellum. See Fig. 25a. 



