Report of the State Entomologist. 



16^ 



upon black and red oak, reaching maturity in August and September. 

 At that period it is solid but fleshy, and when cut into is a pink color 

 inside, shading into yellow toward the middle. Subsequently, as it 

 dries, it becomes so hard as to be 

 cut with difficulty, its color inside 

 changing first to black-red, and after- 

 ward to brown. The insect that pro- 

 duces this gall {Gynipa q. prunua, new 

 species) makes its appearance in April, 

 and is remarkable for lying two years 

 in the gall before it eats its way out, 

 remaining in the larva state over a 

 year : indeed, some of them remain in 

 the larva state for over,two years, and 

 do not eat their way out until the end 

 of the third year. Figure 18, h, shows 

 the same gall when cut open, and c, 

 the central cell inhabited by the larva." 



Fig. 18.— The Oak-plum gall of 

 Amphibolips prunus. 



New Generic Reference. 

 In Mr. "W. H. Ashmead's paper on the " Cynipidous Galls of Florida," 

 giving synopses of the described species of North America {loc. cit. 

 sup.), this species is referred to the genus Amphibolips of Eeinhart 

 {Berl. Eat. Zeits., 1865, 10). This is in conformity with the classifica- 

 tion given by Dr. Mayr, in his " Genera der gallenbewohnenden Cyni- 

 piden," published in 1881, based on a special study of the Euroj^ean 

 species and a large number of American forms. It has been accepted 

 in the arrangement and nomenclature of the Gympidce in Mr. Cresson's 

 recent Syaoj^sis of North American Hymenoptera. 



Description of the Insect. 

 The insect is shown in Fig. 19, in enlargement. Its head is rough; 

 face pubescent; antennse exceeding half the length of the body; 

 thorax coarsely punctate with a 

 conspicuoxis dorsal groove; ab- 

 domen, second joint polished with 

 rather large shallow punctures on 

 its basal three-fourths ; joints 3-7, 

 densely cohered with small con- 

 fluent punctures, giving a silvery 

 appearance; legs rufous; tips of 

 tarsi black ; wings subhy aline ; on j,,^ ,9 _ ^j^e Oak-plum gall Cynips, 

 the front wing, a dark brown Amphibolips peunus. 



cloud extending from the first cross-vein over the upper portion of 



