1882,] 



THE LANCASTER FARMER. 



87 



many millions of dollais, and tlic various 

 fabiics wrouKlit out of its silken fibre are 

 amongst- the most ch^trant and brilliant tliat 

 adorn the human haliilation and the human 

 body. The traffic in silk-worm eggs alone 

 amounts aiujually to many hundreds of thou- 

 sands of dollars, and whole trains of cars 

 freighted wilh them pass through our terri- 

 tory in transit to Kuropean ports every year. 



Again ; if we were entirely ignorant of the 

 value of the little "cochineal insect "—so 

 small, indeed, that when they are dried it re- 

 quires 70,000 to make a pound — their pres- 

 ence would V)o as destructive to the vegeta- 

 tion they feed on, as the famous "cliiiicli- 

 bugs" of the Western States are to the 

 wheat and corn crops. Where the cochineal 

 insect is indigenous, the chief an.xiety of the 

 people is to increase its numbers, because 

 "there is money in it." Therefore it becomes 

 a prolific object of human husbandry, and its 

 failure to multiply would be as much of a dis- 

 aster as the failure of our wheat or fruit 

 crops. You will perceive, then, that the in- 

 crea.se of the silk-worm and the cochineal in- 

 sect are the results of human manipulation, 

 for it is not probalile that either of them 

 would multiply in states of unprotected and 

 unassisted nature, as they do under human 

 intervention. The cactus, the mulberry and 

 other silk-producing trees are carefully culti- 

 vated, and an abnormal increase of the in- 

 sects is thus facilitated. 



We liave a striking instance of tl)e effect of 

 cultivation upon the increase of noxious in- 

 sects in the notorious "Colorada potato-bee- 

 tle." Far up in the Rocky Mountains this 

 insect was discovered about sixty years ago, 

 in moderate numbers, feeding on a wild spe- 

 cies of solanum, and it probably would have 

 remained there, content with its rustic fare, 

 but for luiman intervention. As soon as the 

 domestic potato was cultivated in its vicinity, 

 it abandoned the harsh and comparatively 

 sapless native plant and betook itself to the 

 more succulent vines of the domestic potato" ; 

 and perhaps tiie whole secret of insect prolifi- 

 cation depends more or less upon the condi- 

 tions produced by cultivation. 



The palatable quality of meats and drinks, 

 even among human beings, tends to their in- 

 creased eonsumptio)), and it appears that in- 

 sects are no exception to the rule. The com- 

 mon house-moth will cut a fine, soft, woolen 

 fabric when it is sandwiched between two 

 coarser and harsher pieces and leave the latter 

 untouched. Progressive culture seems to en- 

 gender progressive taste even among such in- 

 significant creatures as in.sects. When we 

 discover some mode of utilizing the Colorado 

 potato-beetle, its iiresence and its increase 

 may become objects of as much solicitude as 

 the increase of the cochineal and silk-worm. 

 These three examples — although tlie utility 

 of the potato-l)eetle has not yet been dis- 

 covered — out of scores of others that might 

 be nameu, amply illustrate one phase of the 

 intimate relations existing between insects and 

 plants. The silk-worm^ by the process of 

 mastication, digestion, absorption and secre- 

 tion, elaborates the tissue known as silk ; and 

 no matter how complicated tlie mechanical 

 machinery is, or how endless the varieties of 

 the silken fabrics produced ; nor how brilliant 

 and gaudy their external sheen, they are all 



subordinate to the humble worm and the 

 leafy j(/a>i(. And although the cochineal does 

 not consume the plant by mastication, yet it 

 absorljH its lluid circulation by suction ; and, 

 by a peculiar chemical sublimation, or distilla- 

 tion', appropriates the fine particles of coloring 

 matter, which become latent in its body and 

 rivals the famous " Tijri<u\ Dye.'''' 



Passing to another pha.se of the subject I 

 would briclly remark, that even among the 

 most destructive in.sects to vegetation, there 

 is some compensation in specific cases. Dr. 

 Ash Fitch, of New York, records an instance 

 of an oak tree on his premi.ses which was in- 

 fested by the common "oak-pruning beetle," 

 and no liuman manipulator of the pruning- 

 knife could have produced the healthful and 

 symmetrical eti'ect upon tlie tree that this little 

 industrious pruner did — cutting off and head- 

 ing in the straggling brandies — making it "a 

 thing of beauty." 



A further illustration of the peculiar rela- 

 tions under consideration may be (bund in 

 the growth of various species of cryptorjamic 

 plants in the bodies and the tissues of insects 

 and other animal substances. Waiving all 

 the microscopic species, I would only remark 

 that it has long been known to entomologists, 

 and doubtless also to botanists, that frequent- 

 ly a large fungoid plant has been found grow- 

 ing out of the body of a subterranean larva of 

 the "May-beetle" or "June bug," common- 

 ly called the " white grub-worm." This grub 

 when mature is about two inches in length, 

 and one inch in circumference, and the largest 

 plant, as recorded in the American Ent,omolo- 

 ijist, sometimes attains a length of five inches, 

 iind grows out of the under side of the first 

 segment of the body. 



Nor is this an isolated case. Mrs. Mary Treat, 

 a distinguished lady entomologist, . of Vine- 

 land, N. J., states that in the spring of 1805, 

 whilst botanizing in Benton county, Iowa, 

 she saw great numbers of them. " There 

 were literally thousands of them scattered 

 over quite a district. " So far ;is the matter 

 has been explored the fungus seems to be 

 unique, although it probably would grow out 

 of different species of the ichile grub. 



Another link in the chain of connection, or 

 relation between insects and plants, finds 

 illustration in what may be termed (Jarnivor- 

 ous plants. The carnivorous character of some 

 mammals, birds, reptiles, fishes and insects 

 is well known, but it may not be so well 

 known that there are certain species of plants 

 that capture and appropriate the juicy sub- 

 stance of insects. They doubtless have other 

 sources of subsistence, but it is quite certain 

 that they also capture and absorb the fluid 

 parts of insects. And this is not all, for they 

 also possess, apparentlj', in/oc/d, in .•itructure, 

 in fragrance and in beaulii, the facilities for 

 attracting and decoying unwary insects into 

 their fatal embraces. But, as this subject is 

 to be, or has been, exemplified in the series of 

 papers read before this society, it is not neces- 

 sary to make any more than this general 

 reference on the present occasion. 



But the most important function of insects 

 in the economy of nature, so far as relates to 

 the vegetable kingdom, is their mcdiuuiship 

 in the fertilization of plants. Although they 

 may assist, or render more complete the 

 fertilization of nearly all plants, yet there are 



quite a number of plants that could not be- 

 come fruitful — so far as human observation 

 extends— without the aid of insects,- and 

 especially those known as Diacious plants, in 

 whicii the male and female flowers occur on 

 two diffi rent individuals. In plants bearing 

 licrmapliiiditr flowers, wlicre the pistillate and 

 sUitiiinale organs are in the same flower, the 

 usefulness of insects may not be so api)areut ; 

 and yet it is very probable that insects a.ssist 

 even in energizing these, and especially pollen 

 gathering insects. 



As to rnowi'ciimis plants— those in which the 

 staminate and pistillate flowers are entirely 

 distinct, although both occur on tlie same 

 plant — 1 feel confident that the function of 

 insects in their fertilization, is much greater 

 than may be generally suppo.sed. 



Take for instance the " Gourd family" — the 

 cwntrbitarrons plants of botauLsts— in which 

 the male flower grows on a stem, or peduncle, 

 from the axils of the leaves, and the female 

 flower is sexsile and attached to the apex of 

 the embryo fruit. The. first-named flowers 

 are usually erect and oi)en upwards, or nearly 

 so, whilst the last-named are usually hori- 

 zontal or nearly so. Although it is not im- 

 possible that these flowers should become fer- 

 tilized without the aid of insects, yet it is 

 very probable that many of them would be- 

 come abortive without such aid. In any 

 event, those who pay any attention at all to 

 the habits of insects will find the.se flowers of- 

 ten visited during the day by a rollicking 

 family of polleniferous hijrncnoptera that seem 

 to be perfectly intoxicated with their foraging 

 manipulations. These insects are provided — 

 on the broad tihius of their posterior limbs, or 

 on the under side of tlie body, near the apex 

 — with bristling brushes, and with these they 

 gather the pollen wliich they bear off and con- 

 vert, by the admixture of nectar, into a sort 

 of "bee bread," or propolis, whicli is stored 

 in their cells for the sustenance of their 

 young after tliey are " excluded " from their 

 eggs. 



Of course, the bees are influenced by no 

 motive, either rational or instinctive, that re- 

 lates to the fertilization of the plant. They 

 rush into the flower cup impulsively, and 

 seem to be in a state of buzzing agitation, 

 gyrating hither and thither, detaching the 

 pollen and scattering it about, but all the 

 while gathering a i)orlion of it with their 

 brushes and then departing as hastily as tiiey 

 entered ; visiting half a dozen or more of 

 flowers before they make their final departure 

 for their homes. It is easy to perceive 

 that these manipulations of the bees facili- 

 tate the fertilization of the plants they 

 visit — indeed. Professor Itiley has demon- 

 strated very conclusively that a certain species 

 of yucca could not be fertilized at all if it 

 were not for the intervention of the "yucca 

 moth." The carpenter-bee, commonly called 

 the "wood-borer," and the various species of 

 liumble or " bumble-bees," arc especially im- 

 bued with this habit. The little "leaf- 

 cutters " are remarkable as pollen gatherers, 

 and they perform a similar use — not only in 

 momrcinus and diercious plants, but also in 

 those bearing hcrmaphoflitc flowers. Darwin 

 has written a clever sized book, in which he 

 conclusively demonstrates that the orchids, or 

 "air plants," are fertilized largely if not ex- 



