158 



THE AMERICAN ENTOMOLOGIST. 



iiiimely, shiftiug from oue kind of small grain 

 to another, would be a perfectly effectual one. 



Lastly, if the law of the Unitv: of Habits be 

 a false and fallacious law, then no American 

 farmer can of himself find out auytliiiig about 

 the liabits of any new insect that is infesting 

 his crops, without studying out those habits in 

 detail — which is often a good twelvemonths' job 

 of work. "We hope it is not now necessary to 

 add, for the information of our regular readers 

 at all events, that, without becoming acquainted 

 with the habits of any particular noxious in- 

 sect, it is folly to attempt to light him. If, on 

 the contrary, as we maintain and firmly believe, 

 the great Law of the Uxixr of Habits be uni- 

 versally true throughout the Animal Kingdom, 

 then a moderate knowledge of Entomology will 

 enable the farmer to tell, at a glance, to what 

 particular group of insects the new species that is 

 infesting his crops belongs ; and he may then infer 

 the habits of the stranger, with a close approxi- 

 mation to accuracy, from the habits of species 

 which are already well known and are closely 

 allied to that stranger. 



Messieurs the Utilitarians, are yon answered? 



Tlie Remedy. 



We I'epeat, however, for the benefit of those 

 who like to "go it blind" and adopt a prescription 

 without knowing the why and the wherefore, 

 that, whenever you discover the stems of your 

 small grain to be badly affected near the root, 

 in the manner shown in Figure 113, a, then you 

 ought to burn off your stubble ground any time 

 before the following summer, and burn lip all 

 the tailings and refuse straw after threshing. 

 II' you do this, and (^an persuade your neighbors 

 to do the same, you will soon kill out the Joint- 

 worm; if you neglect it, the parasites sent by a 

 kind Providence may perlia^js do the work for 

 you; and again it may be possible that, in spite 

 of the parasites, the Joint-worm may increase 

 upon yon year after year, as it did in Central 

 Virginia from 1848 to 1851, till at lengtli it be- 

 comes an almost unbearable nuisance. 



Postscript. 

 We have only to say in conclusion, that we 

 shall be greatly obliged by specimens of Joint- 

 worm work either on Wheat, Kye or Barley, 

 but especially on the two former plants, from 

 any State in the Union, or from any part of the 

 British Provinces to the North of us. There 

 are sdll several interesting problems respecting 

 this insect that remain to bo definitively solved. 

 For example, does Joiiit-wi)rm work ever occur 

 upon Oats? 



THE WAVY-STRIPED FLEA-BEETLE. 



(Half ha [Phyllotreta\ striohita, Illiger.) 



This insect appears quite early in the spring, 

 and proves very 'destructive to manv of the 

 garden plants and flowers belonging to the natu- 

 ral order Crucifee^, and is especially liard on 

 mustard and all kinds of cresses. Common as 

 is this Flea-beetle, its transformations had never 

 been observed, in this country, till quite re- 

 cently. A closely allied and very similarly 

 marked species (Haltica nemorum, Linn.), 

 occurs in Europe, where it is known as the 

 Turnip Flea-beetle. This last species lives in 

 the larva state, above ground, by mining the 

 leaves of the same kinds of plants upon which 

 the beetle feeds ; and its transformations were 

 first made known by Mr. H. Le Keux in a valu- 

 able paper published in the Transactions of the 

 Entomological Society of London, Vol. II, 

 page 24. 



Our American species, being so closely allied 

 to that of Europe, Dr. Fitch inferred its habits 

 to be the same, and in his eleventh New York 

 Report, he quotes Le Keux's observations as 

 applying to our insect, and reproduces from 

 Curtis's '-Farm Insects" the figure of a mined 

 turnip leaf, in illustration. In the December 

 (1868) number of the American JSTaturalist , 

 however. Dr. Henry Shimer of Mt. Carroll, 

 Ills., shows that our American insect lives in 

 the larva state underground, where it subsists 

 on the roots of plants, in the same manner as 

 does the larva of the common Cucumber-beetle 

 (Diabroti.ca vittata, Fabr.) ; and we thus see 

 that it is not always safe to judge of an insect's 

 habits by those of its nearest allies. We have 

 ourselves frequently searched in vain for the 

 larviB on the leaves of both mustard, cress, rad- 

 ish, and lettuce plants that were thickly cov- 

 ered with the perfect beetles, and as Dr. Shim- 

 er's observations are of interest, we quote Iheni 

 in part: 



" The Striped Turnip-beetle (Fig. Hi) a) is less 

 than one-tenth of an inch in length. Its gen- 

 eral appearance is black, with a broad wavy 

 yellowish, or bnft-colorcd 

 stripe, on each wJng- 

 cover. The larva (Fig.119 

 6) is white, with a faint 

 darkened or dusky me- 

 dian line on the anterior 

 half of the bodv, being 



Colors— (n) black and Ijuff- i i , ,, ' . . .. 



color; (innac) whitish, probably the contents ot 

 the alimentary canal seen through the semi- 

 translucent skin. The head is horny and light 

 brown. On the posterior extremity is a brown 



