384 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 13 
ilar pupal cells. Doryctes maculipennis Rohwer, n. sp., was reared 
from cocoons found in both the larval mines and the pupal cells. 
Another species of Doryctes was reared in numbers from cocoons 
found in the same places. In one locality near Palo Alto 50 per cent 
of the girdlers were parasitised by this species. Several cocoons occur 
packed in the same cell or mine. Callihormius sp. was reared from the 
larval mines and possibly the pupal cell. 
Ptinobius agrili, Rohwer 1 n. sp., larvae were found to emerge from pre- 
pupal girdler larvae in the pupal cells and formed naked pupae. Only a 
single one was found in each cell. Metapelma spectabilis Westwood 
was reared from the girdler-infested twigs. It may be a hyper parasite. 
Tetrastichus anthracinus Ashmead, a small black tetrastichid, was 
the commonest parasite reared. It occurred in numbers in the larval 
mines and pupal cells of the girdler. As many as seventeen larvae 
were found in one girdler larva. Sometimes the girdler larva was 
killed before it made the pupal cell, and sometimes afterward. The 
Tetrastichus larvae then emerged and formed naked pupae in the mines 
or cells. Dinotus agrili Rohwer, n. sp., was reared several times from 
girdler-infested twigs sent in from Pasadena by Dr. A. G. Smith. 
Methods of Control 
The best method of control developed at the present time is the 
pruning of the infested twigs. This should be done in the spring 
about April first before the beetles emerge. At this time both 
the twigs infested for one year and for two years are easily distin¬ 
guished and those infested for the two years must be treated if the 
infesting insects are to be killed before they emerge. As many of 
the infesting girdlers are parasitised, it is better not to burn the 
infested twigs but to cage them in a box or barrel with the side or 
top made of number 16 mesh wire screen. The beetles cannot get 
through this and will soon die, while the parasites will escape and 
attack the twig-girdlers in the infested twigs overlooked in the pruning. 
Poison sprays used against caterpillars in the spring kill some of the 
beetles as they feed on the foliage before mating. Contact sprays used 
against scales and other bark pests may kill some of the eggs, but it is 
doubtful if it will pay to use either of these if fighting only the girdler. 
FIELD EXPERIMENTS FOR THE CONTROL OF THE APPLE 
MAGGOT 
By Glenn W. Herrick, Ithaca, N. Y. 
In 1910 the writer urged Dr. J. F. Illingworth, then a graduate 
student at Cornell University, to undertake an investigation of the 
1 Rohwer, S. A., Proc. Ent. Soc. Wash., Vol. 21, pp. 5-8. 
