11 
they grow in size and strength they gnaw irregular holes through the 
leaves, until they are completely riddled or honey-combed and the cab- 
bage rendered thereby unmarketable. 
Natural Enemies and Parasites. — Comparatively few natural enemies 
have been observed preying upon this insect, although carabid beetles 
and others are supposed to destroy it at the North. 
A European chalcid fly, Copidosoma truncatellum Dalman, has been 
reported as parasitic on this species at Washington, by Mr. L. O. How- 
ard; twenty-five hundred and twenty-eight specimens of this parasite 
were actually counted as coming from a single parasitized worm. 
Professor Riley has also bred an ichneumon fly, Apanteles congregatus 
Say, from larvrn. 
Here, in a single instance, I bred from a chrysalis an ichneumon fly 
( Limneria , sp.) a common parasite of the Cabbage Plutella, and it will be 
found treated further on under the parasites of that insect. 
From the egg, however, I bred a pretty little chalcid fly (Trichogram- 
mapretiosa Riley). It was first described by Professor Riley in Canadian 
Entomologist Vol. XI, page 161, from specimens bred from the eggs of 
the Cotton Worm ( Alelia argillacea Hiibn.). 
Besides the above parasites, three larvae were brought under my ob- 
servation, attacked by the parasitic fungus ( Botrytis Pileyi Farlow). 
Remedies. — Pyrethrum. — Professor Lintner recommends pyrethrum : 
“A tablespoonful of good fresh powder, diffused through 2 gallons of 
water and sprinkled over the plants, would destroy the larvae.” 
Hot Water . — Every worm visible upon the cabbages maybe killed by 
the use of water at the temperature of 130° Fahrenheit, or 55° centi- 
grade. The water may be boiling hot when put in the watering-can, 
but it will not be too hot when it reaches the cabbage leaves. The thick 
fleshy nature of the leaves enables them to withstand considerable heat 
with very little injury. The sacrifice of a few heads of cabbage will 
soon teach an experimenter how far he can go with the hot water. It 
may be sprinkled over the plants from a fine rose watering-can or poured 
on with the sprinkler removed. If it is very hot it will color some of 
the leaves, but even where the cabbage is considerably sorched it will 
recover and renew growth from the heat. (Prof. C. Y. Riley). 
Kerosene Emulsion. — The kerosene emulsion, as formulated by Mr. H. 
Gr. Hubbard for scale insects, will also be found valuable for cabbage 
worms. 
Lime and Carbolic Powder. — This is also good. Take 20 parts super- 
phosphate of lime, 3 parts fresh air-slaked lime, and 1 part carbolic 
powder; mix, and scatter a small quantity upon each cabbage head three 
or four times at short intervals about three days apart. The carbolic 
powder is made by taking sawdust and thoroughly impregnating it 
with carbolic acid. 
