424 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 11 
February 4, 1917, fourth brood adults appeared; last one died 
March 10. Meantime, mites swarmed on root and stem, and the 
plant soon wilted beyond revival. It seemed to be impossible to get 
any clover material started for tests without having it fouled by the 
above mite sp. 
August 31, 1916, another sending of dying red clover crowns from 
the Twin Falls South Side tract yielded the same mite and a new 
species, Hologamasus inarmatus Ew. Although coaxing this clover 
crown into growth, it soon wilted under the mite attack presumably, 
no maggots being present. A heavy teaching schedule prevented 
detailed life-history work, but Sciarid larvae have been preserved in 
balsam. If by chance R. rhizophagus is found to have habits as no¬ 
torious as the bulb mite, R. hyacinthus Boisd., clover in irrigated sec¬ 
tions will need further study. 
An unexpected setback overtook operations by growers in spraying 
nicotine and soap for bean thrips ( Heliothrips fasciatus Perg.). At 
the usual strength and put on with an orchard power sprayer, this 
insecticide failed to wet a large part of the infestation. A visit later 
showed that a concurrent attack of red spider mite (Tetr any chits tel - 
arius L.) had so webbed the leaves as to protect large numbers of thrips 
from a wetting. Large losses in beans from this epidemic occurred 
throughout Idaho in 1916 but not in the backward season of 1917. 
Field crop losses in Idaho run into the millions annually, and though 
figures have been compiled, I hesitate to give them. 
EXPERIMENTS ON COCKROACH CONTROL 
By E. V. Walter, Ames, Iowa 
Poison and traps of various kinds have long been used for cockroach 
control. At best traps cannot be relied upon as a means of extermina¬ 
tion, since they only alleviate conditions. Certain proprietary roach 
poisons on the market have given good results but these are all high in 
price. Moreover cockroaches are so wary that, when a few have been 
poisoned, others will not feed unless starved to it. 
The material for this article is taken from notes by the writer while 
employed as an assistant in the Entomology Section, Iowa Agricultural 
Experiment Station, in the summer of 1917. The work Avas undertaken 
at the suggestion of R. L. Webster when the manager of a local cafeteria 
called for assistance in controlling cockroaches. 
J. A. Lintner 1 seems to be the first writer to tell of the use of borax 
1 Injurious Insects of New York. First Report, 1882, p. 343. 
