Tlll{ OUTDOOR WORLD. 



277 



INTERESTING SUGGESTIONS AS TO 

 GALLS. 



BY FREDERICK SCHWANKOVSKY JR., 

 DETROIT, MICH. 

 Late in autumn if yon examine the 

 stems of the golden rod, you will notice 

 here and there a stem bearing: a huge 

 globular swelling- as big often as a fair 

 sized plum. This is a gall ami if you 

 cut one open you will find in the centre 

 of it the home of a small grub. "Ques- 

 tion: How did it get there and why 

 the swelling;? 



The egg hatches and the larva eats into 

 the stem. .Meantime it excretes a poison 

 which caused the abnormal growth called 

 a gall. Each different kind of gall in- 

 sect uses a particular plant apparently 

 and, if the galls are placed in bottles not 

 tightly closed the flies or gnats will 

 emerge toward spring. 



I went further in my investigations 

 than merely letting the insects peace- 

 fully emerge. 1 cut a gall of each sort 

 open from time to time and noted 

 what change had taken place. in the 



A VARIETY OF COMMON GALLS. 

 A, galls on an oak twig; B, mossy gall on a brier rose; C, bud galls ( pine cone 

 galls) from willow; D, a peculiar gall found on a brier rose; E, globulous galls from 

 oak twig; F, wild blackberry galls; G, golden-rod galls. 



Last fall T became much interested in 

 galls and when 1 rode the old horse out 

 through the woods I used to have an eye 

 out constantly for them. I collected a 

 number of varieties, from the golden rod 

 first and afterward from raspberry bush- 

 es, from oak trees and willows and from 

 the wild briar rose. 



On investigation I found that the gall 

 is formed by the larva of gall flies or gall 

 gnats. The adult places the egg, by 

 means of her long sting like ovipositor 

 in the green tissue of the growing plant. 



case of the golden rod -gall called Try- 

 peta Solidaginis of the muscid family, 

 and therefore a relation of the darling 

 little house fly, the larva is first found 

 small and naked, it then increases in size. 

 Next it pupates, that is its outer skin 

 dries bard and the grub lies dormant 

 within it. If a pupa is opened the grub 

 is found assuming the form of a fly with 

 little fleshy wings and all of the grub 

 color. Later still it turns dark and fin- 

 ally breaks the dry skin and works its 

 way out of the gall and after crawling 



