THE BIOLOGY OF THE JUNIPER BERRY INSECTS, 
WITH DESCRIPTIONS OF NEW SPECIES.* 
By S. MARcovitcH, 
Division of Entomology, University of Minnesota. 
In the spring of 1913, Professor Crosby, of Cornell Univer- 
sity, suggested that I work out the life history of two chalcids 
bred by him from deformed berries of Juniperus virginiana L. 
There was also an Eryophyid mite present within the berries, 
so that at first it was difficult to tell which one deformed the 
berries and what were the relations between them. 
In the fall, I discovered a Tineid larva eating the seeds, 
while a little later, a Dipterous larva was found eating the fleshy 
portion of the berry. The latter has proved to be a new species 
of the family Trypetidz. Since then, I have found a Cecido- 
myid larva, and have reared six species of chalcids from the 
berry, at least two of which are plant-feeding in habit. It 
seems rather remarkable, at first, to think that so many insects 
are able to find food in such a small fruit; yet when it is known 
what a role the mite plays, and how completely the berry is 
utilized, it does not seem so strange. 
The Mite—Character of the Injury. From the observa- 
tions of others and from my own examinations, the berry was 
found to be deformed by the mite, it being classed as a mite gall. 
Massalongo, 1889, in describing this gall, thought that the mite 
penetrates the young ovule through the micropyle before the 
ovule scales become fleshy. Fertilization is thus hindered, and 
as the scales become fleshy as usual, it is probable that the 
physiological stimulus of fertilization necessary for growth is 
substituted by the pathological stimulus of the parasite. 
Whether or not fertilization is hindered would be difficult to 
say, as the stigmas of the ovules were open during the beginning 
of the work of the mites, and once a mite entered the ovule, the 
berry was found deformed. 
The normal berry is more or less cone-shaped while the one- 
seeded, deformed berries assume a chestnut shape. In the two 
or more seeded berries, however, the deformation assumes 
* Begun at Cornell University; completed at the University of Minnesota. 
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