THE STATE ENTOMOLOGIST. 57 



feeds in reality on the common Irish Potato, thus swelling 

 the number of insects which injuriously affect that most 

 valuable esculent, to a round dozen. The larva of the 

 Clubbed Tortoise-beetle is not yet known, and it is the per- 

 fect insect which has been found to attack,the Potato. This 

 is doubtless the species which Mr. Huron Burt of Williams- 

 burg, Callaway county, referred to in the Journal of Agriculture of 

 June 6th, 1868, as "a scale-like, terrapin-shaped hard insect, spread 

 out like a flying-squirrel," that adhered tenaciously to the leaves of 

 his potato plants. By referring to Figure 26 the reader will not be 

 slow to learn why these beetles are called Tortoise-beetles, for the 

 patches of dark opaque color which extend on the thin projecting 

 semi-transparent shell of that species, remind one very forcibly of the 

 paws of a mud-turtle. The true legs however, which, as in all other 

 insects, are six in number, and which in this species, are so short that 

 they scarcely reach beyond the thin shield-like crust that extends from 

 the body, may readily be seen when the insect is turned upside down. 

 The insects which attack the Sweet-Potato are few in species, 

 and. belong almost entirely to this group of Tortoise-beetles. With 

 [Fi§;. 27.] the. exception of the Cucumber Flea-beetle 



(Baltica cucumcris, Harr.), figured and de- 

 scribed on page 1Q1 of the First Report, and 

 a few solitary caterpillars, I have never 

 found any other insects on this plant; but 

 these Tortoise-beetles are of themselves 

 sufficiently numerous in individuals and 

 species to often entirely destroy whole fields of this esculent, and 

 they are especially severe on the plants when newly transferred from 

 the hot-bed. 



These insects are at present included in the great Chrysomela 

 family of beetles, though they were formerly placed in a separate 

 family (Cassidid^e) by themselves, and there certainly are few groups 

 more strongly characterized. They are almost all of a broad sub- 

 depressed form, either oval or orbicular, with the thorax and wing- 

 covers so thoroughly dilated at the sides into a broad and flat 

 margin, as to forcibly recall the appearance of a turtle, whence the 

 popular name. Many have the singular power, in a greater or less 

 degree, of changing their color when alive, and as I shall show 

 further on, some of them shine at will with the most brilliant me- 

 tallic tints. 



Insects, as with the higher animals, usually void their excrement 

 in such a manner that they effectually get rid of it, and in some cases 

 they take pains to fling it as far from them as possible, by means of 

 their hind legs. I have especially noticed this cleanly habit in the 

 Oblong-winged Katydid (PhyUoptera oblongi folia, DeGeer), of 

 which I have had numbers breeding in confinement during the past 

 two summers. They almost always fling their excrement straight 



