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THE WINGED PHYLLOXERA IN CALIFORNIA.
IN August, 1873, the subject of phylloxera The French recognize four distinct forms, was first discussed in Sonoma. While it as will be noticed in the following synopsis: was generally known, for a few years previ- Beginning with the form as it exists in winous to this time, that the vines in some ter, we will find a small, dormant, dark localities were “sick,” yet the true cause of brown aphis, somewhat flattened, having no the decay was unknown; and it was not un- wings, and quite unlike the usual mother of til a year later that the Sonoma Vinicultural the summer
With approaching Club proved, beyond a doubt, that the spring, this insect becomes active, and either dreaded phylloxera had already a strong ascends to the upper part of the vine and foothold on this coast.
becomes the gall insect, or descends to the Various theories were immediately pro- roots and forms the root type, either direcposed regarding the manner and time of tion of movement depending upon the surtheir introduction, but none up to the pres- rounding atmospheric conditions. ent time can be relied upon with certainty. The gall insect is not found in California, European vines were introduced in 1860 and and therefore does not interest us. It is 1862, and without doubt a portion of the the insect which descends to the roots that trouble may be traced to these importations. will finally produce the winged form. After The native vines shipped from the Missis- passing through three changes, or sheddings sippi Valley may likewise have been in- of the skin, the mother insect is developed. fested. The exact manner of their intro- Several generations will thus be produced duction still remains a mystery. Still more during the summer, and the increase will mysterious, however, is the non-appearance continue until the last mother louse dies, in of the form which increased the rapidity of the early part of winter; the younger insects the spread in France and other European are destined to become hibernants. If incountries, and makes the pest far more de- stead of three changes the insect passes structive than we find it in this State. With through five, another form, called the pupa, the assistance of the winged form, a distance is the result. This is the first indication of of a few miles between districts offers ap- the winged form, and is easily distinguished parently no barrier to their progress. Not by the small black pads on each side of its only was this form necessary to the rapid back; these contain the infolding rudimenspread of the insect, but has long been con- tary wings. The next change produces the sidered a necessary stage in the complete fully developed winged form, which presents, cycle of its life history. This most dreaded with its beautifully colored body and four form, found in all other countries, has es- delicate wings, a striking contrast to the dull caped the closest search upon the part of appearance of the winter form. The winged California vineyardists until recently, and its form lays the eggs for the development of appearance at so late a date, leaves a doubt the true sexual individuals, which are again as to whether it may not, at any time, de- wingless, destitute of suckers and digestive velop into all forms common to the insect, organs, and seem to have but one mission in and be as destructive to our vineyards as to life—to produce the winter egg for the rethose in France.
juvenation of species in the following sumIn order that we may understand more mer. clearly the position which this new form It must not be understood that the insect holds in the life history of the fully devel- passes through just three or five changes, or oped insect, a short sketch of its changes, moltings, but this seems to be the average during metamorphosis, will be necessary. number under ordinary circumstances. The
different number of changes produce two cy- oped into the complete winged form, showcles of life—one incomplete—which the insect ing clearly that, under proper conditions, may pass through during a single summer. our phylloxera would pass through that In California, the incomplete cycle is prob- stage, which up to this time seemed to be ably the prevailing one, and it would appear missing. But strangely enough, they were all, that they can go on indefinitely without de- or nearly all, of the infertile variety—a variety
— veloping further than the three changes not abundantly found in European vinewhich produce the mother form. The pro- yards. duction of the sexual individuals
Since the above were developed, I believe unnecessary. With the two different cycles none have been positively identified until there arise two different forms, larvæ and last summer (1882) when they were found eggs, which may pass the winter in a in very small numbers, in the pupa form, on dormant state. The eggs, in
the roots; and in one case a fully developed country like the southern part of France, one on the vine itself. In only one or two are frequently hatched at the beginning of cases was the winged form developed during winter, into a form of insect similar, if not the summer in bottles. Apparently, when all identical, to the hibernating form of the conditions are favorable they develop abunmother louse; more frequently, however, dantly; for, while making some observations they are not hatched until spring. Here, at the State University, I have taken at then, at the beginning of spring, the forms least fifty insects, in the pupa state, from a from both cycles are the same. It may be single small bottle. Soon after removing well to notice that in California no winter them, they developed into mature winged eggs, and only comparatively few winged in- insects. All the insects, as far as noticed, sects, have been found.
were fertile ; and very soon after they obA very peculiar phase in the development tained their wings, each laid a solitary egg, of the incomplete cycle was noticed by Bal- and died. They were taken from the bottle biani while observing the Phylloxera quercus, one day, and in less than twenty-four hours a species closely allied to Phylloxera vastatrix, some of the eggs were laid. Each of these or grape phylloxera. He has since observed insects should have laid from six to eight the same change to take place among the eggs, judging from the number laid by the grape phylloxera. It had long been held corresponding form in France; but the conthat the last stages of the winged form of ditions under which they were placed were so P. vastatrix alone produced true sexual in- unfavorable, that no doubt their lives were dividuals. By Balbiani's observations it was much shortened by the treatment. Howclearly shown that during the latter part of ever, they have been frequently kept some the season the wingless form sometimes per- time on a plate of glass without apparently forms the same function as the winged form suffering from the change from the roots. in producing the sexual individuals. This The exact time required in passing from offers an excellent explanation for the con- the pupa state to the laying of the egg is tinued prolificacy, for so many years, of the uncertain; but it is presumably small, as Californian phylloxera without the interven- the winged insects were removed from the tion of the winged form. The number “trap” as soon as discovered. They were of eggs laid are the same in either case, supposed to have been entrapped by the their characteristics are similar, and both moisture on the inside of the bottle soon forms end in the production of a single win- after they became winged; and if this be so, ter egg.
the life of the winged insect must be short In 1879 Dr. Hyde of Santa Rosa first indeed. succeeded in producing the winged form in I have said that there seemed to be “spethis State, from root samples taken from cial conditions” necessary for their developSonoma district. Seven insects were devel- ment. I was led to believe this from the
fact that out of twenty-five bottled speci- been very few; and many cases of rapid mens of roots, only two had the slightest in- spreading have been attributed to this dications of developing this form; and of form because they could be accounted for these two, upon one was found the partly in no other manner. Yet the sudden dedeveloped form as soon as the root was caying of several acres of vines, all possibly taken from the vineyard. As the specimens infested from the same spot, and on the leewere taken from all parts of the vineyard, it ward side of the decaying district, forces the is quite natural to conclude that only one or conclusion that the infection must be carried two vines had the special conditions neces- by the winds, and if so, the winged form sary. A thick bunch of young, tender, must have prevailed to a considerable extent. fibrous roots produce the form in greatest There are notable cases in which narrow abundance. The first supposition is again strips, extending in the direction of the presupported by the fact that the form has been vailing winds, have become infested and found in the vineyards in only four different completely and rapidly destroyed, while adplaces, and upon about as many different joining portions of the vineyard remained vines. A single vine will produce this form, untouched. In other cases, the whole vinewhile none will be found on the surrounding yard seems to collapse in the course of one vines. Diligent search was made last sum- or two years. Happily, these cases of such mer for this variety on a large number of rapid destruction are few, and are the exvines, while looking for the common form of ceptions rather than the general rule. If the the insect, with results as stated above. winged form prevailed in all the vineyards,
The pupa are found near the surface of the spread would be more sweeping, leaving the ground, and also to a depth of five or fewer vines in a healthy condition, as six inches. It is still doubtful whether they now find them. become fully developed winged insects be- Probably the most peculiar phase of the fore leaving the roots; but as the form has insect's workings is shown in some of the never been found on the roots, it is presum- vineyards of Napa County. In these places able that the transformation does not take the manner of spreading is entirely different place until they come to the surface of the from any thus far noticed; and if a typical ground. This may account for the unusual spread by the winged form is possible, and is activity of the pupa, for their existence in to be found anywhere in California, it would this form, at best, is short; so their upward seem that it is developing here. No other movements must be as rapid as possible. vineyards of the State have the appearance
At the time I took the winged specimen of being similiarly infested. Several vinefrom the trunk of the vine, I also bottled yards are included in the group. In two an active pupa, taken three to four inches notable cases only two or three vines in a below the surface of the ground. In less group have the characteristic short growth. than twenty-four hours this also became Surrounding these spots are from one to two a winged insect. Possibly the removing acres, dotted here and there with single inhastened the development; if not, it shows fested vines. The only indication of disease that their rate of locomotion is quite rapid, was a slight change in color ; otherwise, the considering the obstacles they meet in the foliage and fruitage was fully equal to that way of hard soil and other impediments. of any other part of the vineyard. It seems
Keeping in mind the small number of impossible that the vines could have beplaces in which the winged form has been come infested in any other way than by the found, we may consider the vineyards as winged form. The sickly vines were scatnearly exempt from this form, although tered in all directions from the original spot, there are spots which seem to show, by the mainly toward the valley ; cultivation could more rapid spread, its existence in appre not have distributed the pest so impartially; ciable numbers. But such examples have moreover, they were all in the same stage of decay. Both vineyards were affected in pre- yet no signs of rapid spread. In the older cisely the same manner, and had the same and more noted phylloxera districts, instances appearance throughout. It is also a notable of rapid spreading are becoming more nufact that surrounding vineyards were more merous, and anomalous cases are occurring or less similarly dotted with yellow vines, more frequently, indicating a possible designificant of phylloxera, although no original velopment of the new form. source could be located as a starting point. In studying the different phases in which Vineyards two years old were affected equally this insect is found, one cannot but notice with older ones. In several acres of a two- the striking changes which may be produced year-old vineyard single vines could be by accustoming the insect to varying condi“spotted” as infested. Cultivation in so tions. The gall louse may be entirely driven young a vineyard could scarcely have brought from a vineyard by replacing the vines with the pest from a distance. The choice, then, other varieties; the common root form may, lies between infested cuttings and winged after several generations, be persuaded to form.
live above ground upon the leaves, without The greater ease with which the winged assuming the characteristics of the gall louse; form is found of late, and the peculiar phase surrounding circumstances will, too, deterof its movements, naturally suggests the ques- mine the length of the life cycles. If the tion, Is not the original form developing into changes can be produced artificially, is there the more dreaded winged form? and may not not a possibility of the different forms being the insect, in time, accommodate itself to the reproduced in the open field? surrounding circumstances, and develop wing- In order to compare the rapidity of proed form as readily as in its native country? I duction of the winged form of California believe when the insect was first discovered with that of other countries, I would note in California no instances of rapid, sweep- what Professor Riley, says of their producing spread are recorded.
The spread was
tion in the Mississippi Valley, and comslow in all directions. Each separate locality pare it with the numbers found in California. where the root insect is found shows that He says: “An ordinary quart preserve jar several years have passed since their intro- filled with such roots (rootlets from vines in duction. Among these are the two districts proper season), and tightly closed, will furin the eastern extremity of the infested part nish daily, for two weeks, a dozen or more of the State. There has been sufficient time of the winged females.” If every vine in a since they became infested to enable the vineyard bears the winged form at this rate, pest to nearly destroy the original vine- it is easy to form an opinion of the vast yards. In one case, where French vines numbers that would thus be produced, and were freely imported, the vineyard has been to see the ease with which they could be almost entirely uprooted, with the exception carried into the air. of occasional solitary vines, which still re- Observation has not yet shown that Calimain, showing too plainly, with their scanty fornia produces vineyards in which all the growth, the cause of their decay. Slow but vines are infested with winged form, but ravery destructive inroads are being made into ther that the vines thus affected are very few the immediately surrounding vineyards. indeed. If this be the case, vineyards at a Still no signs of rapid spreading are visible, distance are not apt to become infested by the The other case spoken of is represented by blowing of the form, for the number which a single vineyard nearly destroyed, while all could be taken into the air must be exceedthe surrounding vineyards are in a healthy ingly few, and the possibility that any one condition. Traveling westward through sev- of these will ever find suitable condition eral districts, one or more vineyards in each for future action in a distant vineyard is will be found to contain well-developed spots, almost beyond calculation.
F. W. Morse.
Not the renowned philosopher, though he had been telescopically observed from no doubt it might be pleasant and profitable some neighboring planet, he would undoubtto consider him and his wisdom, unrivaled edly have been set down by a scientist as a while millenniums have rolled by. The curious specimen of wheeled animalcula.” Plato of my tale is by no means so notable The doctor was a bachelor, and had lived a personage; yet he, too, had more than for a score of years with a family who, his share of wit and wisdom, was quite a though not akin to him, yet made in every philosopher after his fashion, and well de- sense of the word a home for the homeless serveş such attention as his present biog- man. Hither he brought his new canine rapher can win for him.
responsibility, who speedily so ingratiated A small, bright-eyed, quick-eared dog is himself with the family, and was so thormy hero. Come forward and be introduced, oughly adopted by them, that the question O Plato! Hold up your head in your alert, of ownership was merged in common friendbold, little dog style. Now, up on your ship. It was a home so still, so peaceful, hind legs and salute the good folks who, ac- so well ordered, yet so kindly and cheerful, cording to certain savants, are themselves that Plato found its atmosphere wonderfully only just getting well used to that ticklish congenial-a veritable dogs' paradise. position. Now give us your paw in token Out of this pleasant home the little chilof good-fellowship. There, that will do; dren had gone one by one with shut eyenow back to your warm corner-nay, alas! lids and folded palms. There was not one to the land of shades, the unknown country left to be a playmate for the bright little where all good dogs go; for Plato is gone dog. The great, solitary house held only from hearth and home. His biography the master and mistress, the doctor, and must be written in the past tense. “ Ille " Aunt Judy”—“auntie” always and to all, fuit."
though the sweet young voices which had It was in the quiet old Dutch town of named her so mute forever. It Schenectady, on the famous Mohawk River, might have seemed a lonely spot to the that life first dawned upon Plato--unless, lively little dog, if he had lived there in its indeed, as was taught by the illustrious an- days of merry, romping, childish play, and cient Plato, he had pre-existed, and so did but then felt the solemn shadow and silence migrate into a new shape on this occasion. creep over it all; but as it was, he only It was the drowsy month of August, and knew it in its present stillness and serenity, Schenectady is not remote from Sleepy Hol- and was the happy recipient of such loving low; but Plato inherited no somnolent ten- kindness that to him there never was an dencies from birthplace or birthday. Very aching void. early in life he was taken from his native He was a little fellow, weighing only ten place back into a little country town ten or a dozen pounds, swift of foot and motion, miles distant, where he found good friends and showing plainly his terrier blood, though and good fare, and never changed homes not of the usual black-and-tan color. He again--great luck for dog or man !
was of a soft, bright chestnut hue, with a He was the property, nominally, of a coun- single white spot on his breast. try doctor, whose ministrations stretched were short and alert, his eyes clear and penover a wide circuit of country, and who con- etrating, and his tail-ah, what tales that sequently lived so perpetually in his "sulky," tail could tell! That which his beautiful, that, as the “Autocrat” quaintly remarks, “if speaking eyes, his quivering ears, and his