234 



THE AMBEICAN 



None of the last order, except a few of the 

 Tipulidae, have ever been known to multiply 

 so as to be seriously injurious to vegetation. 

 But in the Coleoptera We have the well known 

 White-grub of the May-beetle, and the large 

 Grape-root Borer, in the family PrionidiB ; and, 

 belonging to the Homoptera, is the pernicious 

 Apple-tree Eoot-louse. The second section is 

 limited almost exclusively to the notorious tribe 

 of Cut-worms, all of which belong to the family 

 of Noctuidfe, in the order Lepidoptera. 



These are a few of the more obvious general 

 results which we derive from the obsei-vation of 

 insects, under the two limitations of noxious 

 habits and the larval state. Others, less remark- 

 able, perhaps, but equally interesting, would be 

 suggested by a more minute study of the subject. 

 But this would extend our article to an unreason- 

 able length. 



Insect Embryogeny. — Three years ago the 

 Entomological world was much interested in 

 the discovery of the phenomenon of partheno- 

 genesis in the larva of a gnat (Cecidomyia) . 

 The particulars are given in Dr. Tripps's paper 

 in the Popular Science Review for April, 1867. 

 They are very curious. It has not hitherto been 

 surmised that the larva oi Aphropliora spumaria, 

 the Cuckoo-spit, affords another instance. Baron 

 DeGeer, the great Swedish naturalist, noticed 

 that the female Frog-hoppers (so the perfect in- 

 sects are called) become so gravid in September 

 that they can scarcely fly. The eggs could not 

 well cause this inconvenient gravity, because 

 they are deposited at a much later season — in 

 England certainly, and probably in Sweden also. 

 The eggs do not seem to encumber the insect, 

 according to my observation, even in December 

 immediately before their deposition. We may, 

 therefore, suppose DeGeer's observation to have 

 applied to females about to become viviparous, 

 though he does not seem to have suspected it. 

 That it might have been so is rendered certain 

 by the occurrence of an embryo within the 

 abdomen of a larva taken in my garden, and 

 now in my cabinet. The claws, eyes, proboscis 

 and antennae are to be clearly distinguished, 

 and even the lenses of the eyes, when consider- 

 ably magnified. The antennae appear of an 

 unusual size, but they comprise only the normal 

 parts, and are obviously immature. The mother 

 larva in this example is about three-parts grown 

 to maturity, the wing-cases being still incom- 

 plete beneath the outer skin. * * * it may 

 now be left to entomologists and physiologists 

 to pursue this new fact, unexpectedly started 

 upon a well beaten field. — Science Gossip. 



IPECTS IJr.IURIOUS TO THE GRAPE-\TNE.— No, 

 The Grape-vine tluite 



{PieropJiorus periscelidactylus , Pitch.) 

 „. [Fig. US.] 



Colors— (n) white; (6) light-brown; (<;) tiiwny-yellow. 



Just about the time that the third bunch of 

 grapes, on a given shoot, is developing, many 

 of the leaves, and especially those at the 

 extremity of the shoot, are found fastened 

 together more or less closely, but genei-ally so 

 as to form a hollow ball. These leaves are fas- 

 tened by a fine white silk, and upon opening 

 the mass and separating the leaves, one of two 

 caterpillars will generally be found in the re- 

 treat. We say one of two, because the retreat 

 made by the smallest of the Blue Caterpillars 

 of the Vine, namely, the larva of the Pearl Wood 

 Nymph (Fig. 102, a, p. 152), so closely resem- 

 bles that of the Grape-vine Plume under con- 

 sideration, that until the leaves are separated it 

 is almost impossible to tell which larva will be 

 found. Both occur at the same time of year, 

 and both have becTi more destructive than usual 

 the present season in the vicinity of St. Louis. 

 In an ordinary season they do not draw together 

 the tips of the shoots till after the third bunch 

 of grapes is formed, and in devouring the ter- 

 minal bud and leaves, they do little more than 

 assist the vineyardist in the pruning which he 

 would soon have to give. They act, indeed, as 

 Nature's pruuing-knives. But the late severe 

 frost which killed the first buds this year, so 

 retarded the growth of the vines that the worms 

 were out in full force before the third bunch had 

 fully formed, and this bunch was consequently 

 included in the fold made by these worms, and 

 destroyed. 



