58 HALF HOURS WITH INSECTS. [Packard. 



fact that it inhabited the pupae, or chrysalides, of butterflies. 

 This insect has been known to inhabit this country since 

 1844, as there are sjiecimens in tlie Britisli Museum taken in 

 Hudson's Bay Territory in that j'ear ; so that it is probably 

 indigenous to both countries, while its present host in North 

 America is the imported cabbage butterfly introduced in 

 1857. 



I have found that another parasite attacks this insect, as 

 the larva of a species of Tachina (Fig. 45) occurred :'n the 

 body of a caterpillar. Doubtless others Avill eventually be 

 found to take up their abode in the body of this insect. It 

 would be interesting to learn whether the birds prey upon 

 the butterfly or caterpillar, and whether they assist in reduc- 

 „ ., ing the number of these pests. We can but 



hope that the present enormous numbers of 

 these worms will, as soon as the insect becomes 

 fully domesticated, be held in check by the 

 united efforts of gardeners and the natural ene- 

 mies of the insect. 



As the worm eats the interior of the cabbage 

 ^ ^. or cauliflower it is difficult to deal with. Some- 



Tachina larva. 



thing can be done by showering the heads with 

 a solution of carbolic acid or strong soap suds, but it is 

 better to employ hand picking, and when the plants are 

 hopelessly infested to throw them on a hot fire. If fed to 

 animals the worms will manage somehow to escape. 



The Cabbage Web-motli. — Another destructive insect, which 

 is almost cosmopolitan in its distribution, is a little green 

 caterpillar, which at times so abounds on the outer leaves as 

 to threaten the destruction of whole fields of cabbages. It 

 is most abundant in a warm and unusually dry season. Dr. 

 Fitch was the first to observe it in Illinois during the year 

 1855. He named it Cerostoma brassicella. but it is un- 

 doubtedly the well known European Plutella xylostella, and 

 first described by Linnaeus. Though the insect has been 



26 



