520 



Garden and Forest. 



[October 30, 1889. 



hand of art thought proper to conduct them, watering here 

 and there chi^erent spots of verdure, and in their progress re- 

 fresliing- tiie whole." Does the reader wonder, althougli only 

 the grounds, and not the splendid house itself, have been por- 

 trayed, that Pliny had a "very great passion for this villa," 

 which, he says, "was chiefly built or finished" by himself? 

 Or does he marvel that when the g^reat Renaissance of art in 

 Italy occurred centuries later, Pliny's description found a 

 score of commentators and illustrators on paper, or that nu- 

 merous attempts were made to reproduce the beauties it por- 

 traved? ^^ , 



New York. M. G. Van Rensselaer. 



New or Little Known Plants. 

 The Japanese Flowering Apple. 



THERE appeared on page 260 of the present volume, 

 among the notes of our correspondent at the 

 Arnold Arboretum, an account of the different varieties of 

 ornamental Apple-trees cultivated in that establishment. 



No description, however,- can give even a faint idea of 

 the wonderful beauty of these plants at their flowering- 

 time, and even the most successful picture fails to show 

 the delicate coloring of the masses of bud and bloom 

 which smother the branches in early spring. One of the 

 most beautiful of these small Apple-trees is that Japanese 

 variety of Pyrus haccala, brought by Von Siebold to 

 Europe, and known generally in nurseries as Pyrus Makes 

 florihunda. Our illustration, made from a photograph of 

 a tree of this variety which grows in a garden near Bos- 

 ton, shows the habit this plant assumes when it is nearly 

 fully grown, with its long, spreading or upright, wand-like 

 branches and its countless clusters of flowers. The trees 

 are even more beautiful before . the flowers are all ex- 

 panded, as they were when our picture was made, and 

 when the bright red flower-buds mingle and contrast with 

 the pure white petals. There is no tree more beautiful in 

 bloom than this Apple, and none better suited for planting on 

 the margin of a large shrubbery or as a single specimen on 

 the lawn or in a small garden. There is no question of its 

 hardiness ; it grows, in good soil, with great rapidity, and 

 it flowers year after year with always increasing profusion. 



Entomological. 



A Destructive Cornel Saw-fly. 



l^Harpiphorus varianus, Norton.) 



DURING the past two or three years great injury has been 

 done to the foliage of several species of Cornus by white 

 saw-fiy larvse, which, until the past summer, have remained 

 undetermined. These insects have been especially destructive 

 at the Arnold Arboretum and in its immediate vicinity ; but, at 

 other places for twenty miles or more from Boston, their work 

 has been apparent. Indeed, the abundance and destructive- 

 ness of these larvse have caused some people to hesitate about 

 planting specimens of Dogwood for ornament, since, by the 

 end of July or early in August, the plants are apt to be either 

 entirely defoliated or to have their foliage so badly eaten as to 

 Ijecome very unsightly. Specimens of the larvae had been 

 sent to various entomologists for determination, but without 

 result; and other specimens kept in confinement had passed 

 the last moult, but died during the winter or spring without 

 pupating. Early this spring, however, upon breaking a piece 

 of partly decayed wood picked up in the vicinity of Cornus 

 bushes, I found a number of these larvae within it. Many of 

 them had made tunnels from one to several inches in length, 

 the longest borings being in the most decayed portion of the 

 wood. When taken out and exposed to warmth and light the 

 larva; moved in a sluggish manner. 



Several pieces of wood containing these larvae were col- 

 lected and placed in a tight box to await further develop- 

 ments. In the latter part of May the larvae began to pupate, 

 both in the wood and on the bottom of the box, with- 

 out making any cocoons, and in a short time the saw-flies 

 began to emerge. The insect proved to be Harpiphorus 

 varianus, described by Edward Norton as early as 1861 {Proc. 

 Bostoti Soc. Nat. Hist., vol. viii., p. 156), from specimens col- 

 lected at Farmington, Connecticut. 



The saw-flies were seen flying about the Cornels in the 



Arboretum during the Hrst week of June. On June lofli the 

 lirst eggs were discovered and within a few days they were 

 quite al)imdant. The eggs are pale green, oblong, and about 

 four one-himdredths of an inch in length. Tliey are depos- 

 ited singly within the tissue of the leaf on the upper side. 

 From one or two dozen to three or four hundred eggs may 

 be deposited within a single leaf without any very definite 

 order, although most of them are usually disposed in lines 

 parallel with the midrib, or with the principal veins. Each 

 sg'g' makes a little swelling, noticeable on both the upper and 

 the imder sides of the leaf, and, with a little practice, egg- 

 bearing leaves may be readily detected. 



On hatching, the larvae emerge on the under side of the 

 leaf. They are then about six one-hundredths of an inch long 

 and pale green in color, with yellowish head and black eyes. 

 When at rest they keep close together, coiled up on the under 

 side of the leaves ; and they appear to feed only in the cooler 

 parts of the day, in cloudy weather, or perhaps at night. Of the 

 first leaves attacked, they eat only the more tender parts, and 

 the leaves are left somewhat skeletonized ; but as the larvae 

 get older they devour every part of the leaf down to the mid- 

 rib. After the first moult, when they are about twelve one- 

 hundredths of an inch long, the larvcE secrete a peculiar, very 

 white efflorescence, by which the back and sides become cov- 

 ered. This is constant after each moult until the last. 



This efflorescence is removed by the slightest touch, and 

 when brushed off, the color of the body is a pale greenish 

 white. The head, after the first moult, is black, and the legs 

 and under side of the body yellow. At full growth the average 

 length of the larvae is about an inch. Some are smaller than 

 others, however, and this possibly indicates the difference of 

 sexes. 



When the larva has cast its skin for the last time a com- 

 plete and surprising change has taken place. All trace of 

 white is gone, and the body is greenish yellow on the back and 

 yellow beneath and along the sides below the spiracles. On 

 each segment along the back are two large and two small 

 black spots, and upon the sides, close above the spiracles, is 

 a row of nearly square, black spots, one for each segment, but 

 so placed as to lap over from one segment to the next. 



The terminal plate above the ventral segment is black. 

 The legs and prolegs are yellow, the former having a reddish 

 spot oh the outer side near the base. The tips of the claws 

 are black. The great change produced by the last moult has 

 led some observers to suppose that there are two distinct 

 species. 



Full growth is attained by most of the larvae early in August, 

 but some may not reach maturity until much later, and this 

 season a few were noticed to pass the last moult about Sep- 

 tember 2oth. The season last year was not so advanced, and, 

 in some places, large numbers of larvae were found in Sep- 

 tember. The larvae eat very little after the last moult, and 

 very soon they leave the plant and wander away in search of 

 suitable places in which to hibernate. Stray pieces of decay- 

 ing wood, fence posts and rails, dead branches and the corky 

 bark of old trees are selected. In the Arboretum, many were 

 found even boring into the soft pith of dead stems of Elder 

 bushes. Sometimes two or more occupy one burrow. It is 

 quite possible that some larvag go into the ground to hiber- 

 nate, but none have been discovered there. 



Specimens confined in a large glass jar refused to enter 

 some soil placed at the bottom, but when pieces of soft wood 

 were put within reach the larvae eagerly bored into them, and 

 a number also disappeared within the cork stopper of the jar. 

 Once in their burrows, the larvae become much contracted, 

 and remain so until pupation, which usually occurs only a 

 week or two before the perfect insects appear. ■ The males of 

 the latter are considerably smaller than the females, and in 

 the shape of the abdomen they are less pointed, but, other- 

 wise, they closely resemble the females. These may be iden- 

 tified by the following characters : The abdomen is flatfish 

 and reddish brown, sometimes quite dark ; the thorax and 

 head shining black ; the antennae, about a quarter of an inch 

 in length, have the three basal joints rusty colored, the fourth 

 and fifth joints black, and the four terminal joints white or yel- 

 lowish white. The first two pairs of legs are white at the base, 

 the femora are black and red, the tibiae and tarsi light brown, 

 the latter often very light. The last pair of legs are usually 

 white at base of femora, the rest being black or reddish and 

 tipped with black; the tibiae are red tipped with black, and the 

 tarsi very light brown or yellowish white. The wings are 

 clear, the outer half having a brownish or smoky tinge, and 

 they expand nearly three-quarters of an inch in the males and 

 almost an inch in some of the largest females. In length the 

 bodies of the former are somewhat more than one-third of an 



