THE LIFE HISTORY AND EARLY STAGES OF PLATY- 



METOPIUS HYALINUS OSB.,* A JAPANESE MAPLE 



LEAF-HOPPER IN NEW JERSEY. 



By Edgar L. Dickerson and Harry B. Weiss, 

 New Brunswick, N. J. 



For the past several years the writers have noted this species 

 as occurring more or less abundantly on Japanese maple {Acer 

 palmatum Thunb.) in various places in New Jersey, principally 

 South Orange, Plainfield, Springfield, Irvington and Rutherford. 

 During the summer of 1918 it was very abundant at Freehold, 

 N. J., on a form of Norway maple {Acer platanoides L. var. 

 globosum Nich.) and the following notes are the results of 

 observations made at that locality. 



The species overwinters in the egg stage, each egg being 

 deposited singly just under the bark close to a bud on the 

 recently made growth of the twig. The egg is firmly embedded 

 in the tissue which becomes brownish and somewhat hard 

 adjoining it. The outer bark over the egg is raised and some- 

 what cracked and a crack is also present where the egg is 

 inserted. Sometimes the end of an egg protrudes slightly. 

 The egg is inserted so that its long axis is rjiore or less at right 

 angles to the tissue and a favorite place for deposition is the 

 thickened part of the twig around the buds. Sometimes eggs 

 were found in groups of two to five each egg being separated from 

 the other, however, by considerable tissue. 



At Freehold, N. J., hatching took place about the first 

 of June and continued for almost a month. As late as early 

 July it was possible to find first stage nymphs. From eggs 

 hatching the first few days in June, adults appeared the first 

 few days of July, showing that about one month is necessary 

 for the development of the five nymphal stages. This is 

 probably the maximum time and would be shortened by very 

 warm weather. On account of the uneven hatching of the eggs, 

 it is possible to find all nymphal stages and adults present 

 during the first part of July. By the end of July practically 

 all of the nymphs have matured and at this time and during 

 the first of August the adults are most plentiful. Over- 



* Identified by E. P. Van Duzee. 



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