ON THE DAHLIA. 243 



Russeliana Althea rosea, even the herbs Mentha viride, and Melissa 

 officinalis have not escaped its ravages. I have also caught it on 

 terminal shoots of some species of Prunus. The same insect 

 produces the curl in the potatoe, about the cause of which, so 

 many volumes have been ignorantly and erroneously written. 

 These insects are never numerous, two or three on one plant are 

 amply sufficient to blast the hopes of the cultivator either of the 

 Dahlia or any other of the numerous plants it infests.- The best 

 remedy, in my opinion for the above evil, is to look over the 

 plants attentively every morning for a week and pick off the in- 

 sects, if any are to be found. In doing which it is necesiary to 

 be careful, as the insect when disturbed by the approach of an 

 enemy, instinctively throws itsself down among the leaves and 

 lower branches, and if again disturbed it precipitates itself to the 

 ground. If it escapes the hands of the destroyer, it again climbs 

 the stem or branch to its summit, and again commences its mis- 

 chievous depredations : so that it is necessary for the gardener to 

 exercise some tact, or he will fail in capturing his enemy. The 

 msect in its pupa state, is without wings, and in both states it is 

 exactly the colour of the foliage of the plant. 



Several other insects inhabit the Dahlia in wet seasons, a small 

 species of acarius hifests the flowers. The Cicoda spumaria is not 

 unfrequent on the Dahlia, in its pupa state it feeds upon the juices 

 of the plant, and produces those frothy appearances vulgarly cal- 

 led cuckoo spit; the perfect insect is about the size ofCymex, from 

 which, however, it may be easily distinguished by its brownish 

 hue. A species of aphis is also common on the Dahlia covering 

 the young shoots and sucking the juices of the plant through the 

 pores of the epidermis; they may be distinguished from the Cymex 

 by their being smaller, more numerous, and more sluggish in their 

 habits. 



The other insects that inhabit the Dahlia, I may perhaps notice 

 in a future communication ; but of all the insects that infest it, by 

 far the most injurious is the Cymex, and I woidd advise your 

 readers, who, doubtless are all Dahlia growers, and wish to grow 

 it well, to be particularly on their guard against the attacks of this 

 insidious and' destructive enemy. 



A Cultivator of the Dahlia. 

 Todmordcn, Sept, I4lb I808 



