COLLECTING GALLS 
The beginner in the study of the gall-making cynipids ie handicapped and often 
diecouraged by lack of published information as to the date of emergence of the 
maker of the gall. Not knowing what time of year to collect the galls to get the 
maker he gets nothing at all or rears only guests and a great variety of chalcids 
and other parasites. Some general suggestions from the writer's experience are 
thought to be of value to the amateur* 
Galls occur on a great variety of plants and are caused by mites as well as by 
many kinds of insects: plant lice, psyllas, gall midges, trypetid flies, moths, 
beetles, sawflies as well as by the true gall flies (cynipids). It is with the 
last that we are here concerned and their galls are restricted to only a few 
host plants, mainly oaks, roses, with a few on composites. In the cynipid galls 
the larvae are always in closed cavities. The larvae are never hairy as in the 
case of the chalcids. Larvae of guest cynipids are not to be distinguished from 
those of the maker. 
There are two main periods in the year for collecting cynipid galls. Those 
on the few herbaceous plants like Lactuca or Silphium may be collected in the 
fall if they can be put where they will not dry out during the winter but are 
better left out in the open over winter and brought into the laboratory in the 
spring. A pasteboard box with a vial in one side makes a good breeding cage. 
The galls on Rubus may be treated the same way. 
The succulent vernal galls on the leaves, buds and flowers of oak, however, 
must be left on the tree until the larvae within have used up all the nutritive 
layer and it is a matter of leaving them some days or at most but a few weeks 
longer. When the larvae are full-grown, or better have changed to pupae, twigs 
bearing such galls can be put in a bottle of water with cotton plugged tightly 
around the stems at the mouth of the bottle so that the emerging flies can not 
get into the water. This bottle is set into a battery jar with muslin over the 
top _ if under a bell-jar condensation water will wet the wings and spoil the 
specimens. If flower galls are not gathered until pupae are inside a small pill¬ 
box is a sufficient breeding cage. From these vernal galls come active, fully- 
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