From the New Haven Daily Herald. 



THE CANKERWORM. 

 We would invite the attention of our citizens to 

 the following article on the Cankerworra. 'J he re- 

 newed foliage with which our shade trees are now 

 covered, has in some degree removed the apprehen- 

 sion entertained a few months since, that we were 

 ID danger of losing one of the chief ornaments of 

 our city. Our citizens ought to be apprised, how- 

 ever, that the effort required to put forth two sets of 

 foliage anually, cannot be sustained, ordinarily, 

 longer than two or three successive years. For 

 one year, or two, this may occur without serious 

 detriment ; but tlie third year commonly proves 

 fatal to the tree. Many of our most valuable orna- 

 mental trees have now been completely denuded 

 two years in succession, and unless measures are 

 immediately taken to secure them from the ascent 

 of insects this season, many of them will probably 

 be lost next summer. The insects will now soon 

 begin to come out of the ground, so that what is 

 to be done ought to be done immediately. We re- 

 turn our thanks to the anonymous author of this 

 communication, which comes to us under the post- 

 mark of Philadelphia, and will forward copies of 

 the paper as he has desired. 



■ .Entomology of the C'anke.rworm—Phalaena Ver- 

 nata Geomatia.—?EcK. — mth general remarks 

 upon the various remeiKes or preventives. 

 From the numerous remarks that I have heard 

 made in various parts of the country, I was led to 

 believe that the character and habits of the Can- 

 Serworm were very imperfectly understood. And 

 as its ravages appear likely to destroy a considera- 

 ble portion of tlie fruit and ornamental trees, I was 

 induced to study its entomology ; and believing it 

 might be useful to those interested in its destruc- 

 tion, I concluded to offer the result of my labors to 

 the public. And I would here suggest to the edi- 

 tors of newspapers, who are fond of fruit, and like 

 to see flourishing trees, to insert the following ac- 

 count for the benefit of their readers. 



The Cankerworms begin to hatch in the sprino- 

 about the time the red currant is in blossom, an°d' 

 the apple tree puts forth its tender leaves, which 

 an Boston, is about the last of April, or the 

 first of May. When first hatched, they are about 

 one tenth of an inch long, and as large as a fine 

 horse hair. Having made their escape from the 

 eggs, they move about with great activity in search 

 of food, and having arrived at the extremities of 

 the branches, they begin to :eed upon the pulpy 

 part of the leaves. And if a leaf is taken and held 

 against the light, it appears perforated with nume- 

 rous small apertures, like pin holes. They acquire 

 their full growth in about four weeks. During this 

 period they cast several skins, each succeeding 

 skin being larger than the previous one. The 

 number of these and the tmie intervening, is not 

 ascertained. As they pass through these stages 

 they become more and more voracious, and in the 

 last stage are more destructive than in the whole of 

 their previous existence, and make no hesitation in 

 destroying the entire foliage, but eat the green 

 fruit. ° 



'J'hese worms spin a continuous thread as they 

 move about, and leave it attached to their path •— 

 hence, if a branch of the tree is struck so as' to 

 give It a sudden shock, the worms may be seen 

 suspended beneath by this silken cord ; and when 

 the shock has ceased, they ascend to the place 

 from whence they fell. Immediately beneath the 



mouth, there is a conical papilla, from whence the 

 fibre that suspends them is emitted. Their ascent, 

 when thrown from the tree, is slow, and is per- 

 formed by bending the head and anterior part of 

 the body back, until the feet in the third segment 

 can grasp the thread ; then bringing the hea°d for- 

 ward, they seize the thread with their jaws ; thus 

 continuing to fold it up until they reach the 

 branch of the tree. They pause at intervals if the 

 ascent is long. If by chance the thread should get 

 broken, they crawl to the trunk of the tree and as- 

 cend. 



The larva, or caterpillar, is, when full grown, 

 about nine tenths of an inch in length, and one 

 eighth of an inch in diameter ; the head pale, 

 marked on each side with two transverse blackish 

 stripes ; the back ash-colored, marked lengthwise 

 with small, interrupted dusky lines ; the side black- 

 ish, with a pale line along the length of the body. 

 There are two white spots upon tlie last segment 

 of the body. The abdomen, or under side, is ash- 

 colored. In moving about, they draw up the 

 hinder part to the breast, bending the body into the 

 form of the letter n ; then extending the body to 

 take a new grasp with the anterior feet, thus ap- 

 pearing to measure the space over which they pass. 

 From this circumstance they are called geomutin, 

 and in English, lopers, span-worms, inch-worms. 



I In about four weeks after they are hatched, they 

 cease eating, and descend to the earth and enter it, 

 from four to eight inches, according to the quality 

 and condition of the soil. For the first few days 

 they continue shortening their body, and drawing in 

 their feet. When they have contracted themseWes 

 sufficiently, they disengage their skin and slip it 

 off, and become a chrysalis, which is about half an 

 inch long, and one seventh of an inch in diameter. 

 It appears that the insect is soon perfect, as some 

 of them in New England rise from the earth as 

 early as the last of September, and they rise, more 

 or less, until the first of May following, whenever 

 the weather suits them, and the ground is thawed 

 to the depth of their abode. 



When they rise from the ground they appear in 

 forms entirely different : the antenns or horns of 

 the perfect insect are setatious. The body of the 

 male is of an ashen amber ,color, nearly half an 

 inch in length ; e.xtent of its upper wings one inch 

 and two tenths; the wings are ash-colored with 

 three obscure blackish stripes, and a small dash of 

 the same color at the tips. The under wings are 

 of a uniform color, and rather lighter than the 

 ground of the upper ones. The body of the female 

 is about four tenths of an inch in length, ash-color- 

 ed and marked on the back with a brown list, ex- 

 tending from the thorax to the tail. She is desti- 

 tute of wings, has six long dusky legs with white 

 joints. Both tiie j.faJe and the female remain quiet 

 during the day and adhere close to the bark of the 

 tree, and are so near the same color they are not 

 seen without close inspection. In a short time 

 after sunset they begin to move. 'Jhe males may 

 be seen flying about. The females being destitute 

 of wings, are under the necessity of ascending the 

 trunk of the tree. They may sometimes be found 

 together, subcupola. After this office is performed 

 the males die, and in a few days the females depo- 

 sit their eggs, about one hundred in number, which 

 are deposited on the branches of the tree and ge- 

 nerally near the extremities. The egg is of an 

 elliptic form, about one thirtysixth of an inch in 

 length, of a pearl color, with a yellowish cast. As 



the included animal advances, the eggs assume 

 brownish hue, and finally become lead colour. Th 

 eggs adhere firmly to whatever they are laid upor 

 and appear something like the top of a thimblf 

 except the indentations are miJch finer, and whei 

 laid in the fall are not injured by freezing bu 

 hatch about the time before mentioned. Durinj 

 the last stage of their existence they do not eat any 

 thing. The female after laying her eggs, having 

 accomplished the object of her existence, dies 

 C lid weather does not have any effect upon th< 

 chrysalis moths or eggs further than to benumb tht 

 millers and grubs (grubs is the name usually ap- 

 plied to the female), until it becomes warm again : 

 for if the insects in this state, when it is e.xtremelj 

 cold, are carried into a warm room, they soon be- 

 come active. A piece of ice containing a numbei 

 of grubs was carried into a warm room. As soon 

 as the ice was thawed so as to set them at liberty, 

 they began to move about the room, and were none 

 the less vigorous for having slept in a bed of ice. 

 They have been known to rise from the earth when 

 tlie water was standing over them and come up 

 through the water. When snow was upon the 

 ground immediately around the tree, they have 

 been known to rise from that part of the ground 

 where there was no snow and cross over the &now 

 to ascend the trees. The greatest natural and 

 most destructive enemy of this insect is the Ampe- 

 li? Garrulus of Linnaeus, called by Mr Calesby the 

 chatterer of Carolina, and in Dr Belknap's History 

 of New-Hampshire, Cherry bird. This bird de- 

 stroys great numbers of them while in the larva 

 stdte. Another check is a disease which may be 

 called Deliquium, and is probably occasioned by a 

 fe|-mentiition of their food. In this disease the 

 whole internal structure is dissolved into a liquid, 

 anj nothing is entire but the exterior cuticle, 

 wljch breaks on being touched. 



The Canker iTor:n is spoken of in the Bible 

 among the judgments which were to be sent upon 

 the children of Israel ; and is said to have been ob- 

 served first in the southern states, where it is pro- 

 bably a native. It is certain that it must have 

 spread by some means independent of itself, aa the 

 female, being destitute of wings, is forbidden to 

 range. It m.iy have been brought into New Eng- 

 land by bringing trees from the southern states 

 upon which the eggs were deposited, or brought in 

 the larva state, into all populous parts of the United 

 States, by falling from trees upon carriages and 

 travellers passing under them. This conjecture is 

 rendered probable, by its being in all places which 

 have intercourse with such parts as are infested 

 with it ; and by its being unknown to new settle- 

 ments. 



There is a tradition among some of the oldest in- 

 habitants of New England that the forest trees 

 were destroyed very generally by this worm at one 

 time; the precise period when this occurred I have 

 not been able to ascertain. The night of the 17th 

 of May 1794, was so cold as to produce ice one 

 third of an inch thick ; at that time a great part of 

 the Cankerworms were hatched ; to these the frost 

 was so fatal that very few were seen. A person, 

 who paid very diligent attention saw but one male 

 the next year. I am firm in the belief thai frost 

 would not kill them at anytime except when in the 

 larva or caterpillar state. 



Having given the best description of the Canker- 

 worm that the above limits would allow, I will now 

 proceed to describe some of the remedies or pre- 

 ventives. It will appear by reflecting upon the 



I 



