7 



other tobacco insects, unless (and this suggestion we make as one of much possible 

 value) it shall be found feasible to grow a few clumps of nightshade or jimson weed 

 as trap crops for the beetles, the plants to be thoroughly poisoned in the early sum- 

 mer before the tobacco has been set out. The tobacco crop is one of a few which are 

 peculiarly adapted to this kind of remedial treatment. In the ordinary course of 

 tobacco culture the weeds are allowed to grow freely about the margins of the fields. 

 Before the tobacco plants are set out those weeds which are secondary food plants 

 of tobacco insects, such as Solanum nigrum, Solanum carolinense, and Datura stramo- 

 nium, act simply as concentrators and multipliers of the tobacco insects, so that the 

 insects are already in force about the margins of the fields, ready to transfer their 

 attentions to the young and succulent tobacco plants after they have been planted. 

 From this it is plain that if the margins of the fields are kept free from such plants, 

 the insects will not have as good a start and will not be present in such great num- 

 bers. It also follows that if a few attractive weeds are left in clumps the flea-beetles 

 and other tobacco insects of the immediate vicinity will concentrate upon these few 

 weeds, where they can readily be killed, either by the application of an arsenical 

 poison, if they are gnawing insects, or of a kerosene emulsion, if they are sucking 

 insects. 



We have in Hawaii many representatives of the plant family Sola- 

 nacese, among which are the following- very common forms: The cape 

 gooseberry (Physalis perwviana), the "poha" of the natives; the jimson 

 weed (Datura stramonium)^ known locally as "kikania;" and Solanum 

 nodifloriim, whose native name is ^popolo." 



Care should be taken not to grow such crops as tomatoes and pota- 

 toes adjoining tobacco fields, unless these crops receive the same careful 

 culture as prescribed for tobacco, and after harvesting both the tobacco 

 and these crops all stalks and vines should be collected and destroyed, 

 thereby preventing the further breeding of any forms of tobacco 

 insects left in the field. 



THE TOBACCO SPLITWORM. 



(Phthorim&a operculella Zell. )° 



The tobacco splitworm or leaf miner is the well-known " potato 

 tuber moth" of California, the Mediterranean countries, New Zea- 

 land, and Australia. A stem of a tobacco plant infested with a single 

 specimen of the larva of this insect was received from the Hamakua 

 experimental field (Pohakea, island of Hawaii) the latter part of Feb- 

 ruary, 1904. The adult moth was bred and forwarded to the Bureau 

 of Entomology. U. S. Department of Agriculture, for identification. 

 The determination was kindly made by Mr. August Busck. During 

 the past season the injury by this pest to the tobacco plants has been 

 considerable and the splitworm promises to be one of the insects that 

 will seriously affect tobacco in Hawaii. The insect was probably intro- 

 duced into the islands in potatoes from California, although it may 

 have arrived in the stewards' supplies from either Australia or China. 



a Lita solan ella, Gelechia solanella, G. operculella, etc., are synonyms. 



