95 



the plant, and the t\n-gs adhere .so tinnl}^ tog-ether, and to the place of 

 deposit, that they are not so easily seen and are also with extreme dif- 

 ficulty detached. Tlie ag^s observed required about a month to hatch. 



The newly hatched larva, which is pale yellow^ish in color witli light 

 brown mouth-parts, is quite active, and upon hatching l)urrows imme- 

 diately into the ground, where it soon acquires a bluish hue. 



The larval period does not appear to have been ascertained, but it is 

 with little doul)t at least one month, and perhaps two or three more, 

 this stage being passed entirely in the ground, where the pupa state is 

 also assumed. As this species lives by preference, at least in most of 

 the United States, under glass, there can be no great regularity in the 

 duration of the periods of transformation. The insect may, in fact, 

 be found in all stages during the winter and early spring months, 

 injury appearing to be most noticeable in December. 



NATURAL ENEMIES. 



A single carnivorous insect appears to have been recorded as prey- 

 ing upon the larva? of this beetle, this observation having Ijeen made 

 in the rearing cages at this Department in 1878. The insect was a 

 wireworm, the larva of a click-beetle, and was somewhat doubtfully 

 referred to Drasterlus aimiblUs Lee. 



Toads are frequently found in greenhouses, and sometimes are pur- 

 posely put in such places to prc}^ upon destructive insects. They are 

 known to feed upon insects related to this rose Ijcetle, and probably 

 feed \\\)on the species in question. 



Natural enemies that have l)een observed by Mr. Koebele in Hawaii 

 include the mina bird and mongoose. 



METHODS OF CONTROL. 



The beetles are so long-lived and hard}' that it is difficult, if not 

 impossible, to destroy them by the use of ordinary insecticides, even 

 hydrocyanic-acid gas ])eing practically^ powerless against them used at 

 a strength that would not kill the plants affected. The remedy which 

 has found most favor is to search for and destroy the beetles, and a 

 good time for this work is during the months of Novcml)er and Decem- 

 ber, when the beetles ma}^ often l)e found congregated upon the plants. 

 B}^ persistently following this method the insect has been practically 

 exterminated in many greenhouses which it formerly infested. By 

 killing the beetles the number of larvre will of course be lessened. 

 Plants showing sevei'(> injury should be pulled out and the soil al)out 

 them searched for the larva'; or the larva^ ma}^ be killed l)v means of 

 the bisulphide of carbon applied to the soil al)out the roots of the 

 affected plants. It should be inserted by means of a metal syringe, a 

 few drops hei e and there about the roots being sufficient to destroy the 



