Alfred Charles Kinsey

“ Sufficient care is not usually exercised to keep separate the several species collected at any one time. Confusion as to the species of the host plant from which the gall was obtained and the hopeless confusion of any adults that may emerge from the galls before they are finally sorted are the results of putting galls of several species into a single receptacle. A large part of museum material is rendered worthless by such methods of collecting. ”

“ The amount of work involved in solving these life histories is rather considerable, and to study any number of the five hundred or more American species of gall-wasps will call for the help of many students. It is to furnish a ready equipment to those who care to undertake such work, as well as to make available for general use a body of data, that I shall gather in this and subsequent papers the available facts concerning the species of which the life histories are known. ”

“ Adler, in working out the life histories of European cynipids, employed only smaller coverings for the trees, but by the use of nets large enough to cover the entire tree it is possible to give a much wider range of activity to the insect; and by placing the breeding jars directly into the nets the danger of injuring these delicate insects by handling is entirely avoided.
The adults of most species of cynipids have very little vitality, and to effect oviposition they must usually reach the part of the plant in which the egg will be laid within a few hours after emerging from the gall. ”

“ It is very interesting to find insects of so little vitality living through such a journey, and upon emergence from the galls to be able to endure the new conditions and to find the hosts necessary for the continuance of the species. ”

“ Galls of the above description, in the Thompson Collection, belong, I believe, to the females of this generation, but the data was not distinctly affixed. From what is known of the life history of the species, it is evident that this generation lives in the galls for about ten and a half months, emerging and ovipositing April 29 (Bassett) to May 10 (Thompson) . As far as known, the generation is agamic. The females very closely resemble the females of the bisexual generation but are readily distinguishable by the larger, more oval abdomen, a character to be expected in the agamic generation. ”

“ The very diverse forms of the alternate generations of many species of gall-wasps and the apparently regular succession of the agamic with the bisexual forms, which constitutes true heterogeny, are not known to be equaled in any other large group of highly developed animals and, consequently, unusually wide attention has been attracted to life histories of gall-wasps. ”

“ If the alternate generation of a species which is being studied is to lay its eggs in the flowers or acorns of the oak, recourse must be had to older trees growing in the open, such additional precautions then being taken as will insure as far as possible the immunity of the part of the tree used from attack by any other gall-wasps than those under observation. Some species will oviposit in the roots of trees. ”

“ Cotypes.—Cotype females, males, and galls in the collection of the Museum of Comparative Zoology. I have examined the types of Andricus notha (Osten Sacken) and the adults appear to be true palustris. The galls are somewhat more oval in shape, with the larval cell more elongate, but I have found that that character shows gradations in large series of palustris and there is little doubt that notha is, as Osten Sacken strongly suspicioned, not distinct. Beutenmüller makes Andricus pusulatoides Bassett a synonym of notha. ”

“ From about two thousand gall-wasps placed upon plants the first year of my work, when the trees were newly transplanted and not growing very vigorously, I secured only twenty galls. The factors influencing the growth of these deformations are hardly at all understood, but it is very likely that the trees on which they are to grow must be in very vigorous condition. An abundance of insects of any one species will usually be necessary to secure any amount of results. ”

“ The adults of ignotus live for only a few days at the most, oviposition often occurring only a few hours after emergence. The females will refuse to oviposit unless they find a bush in the right condition for receiving the eggs A lot of the insects which I placed on a cultivated rose which was somewhat retarded in development refused to climb over the bush at all to examine the buds, though the same insects became active enough when placed on a plant in a more advanced state of development. ”

“ Over ten months will be required for the alternate generation to reach full maturity.
The experiments by which I was fortunate enough to discover the relations of the two generations of this species were made under the strictly controlled conditions which I have described in the introduction. The tree on which the sexual adults were put was covered with a net for almost a month and there was no chance of other insects having reached it during that time, nor is there much likelihood of the galls having been produced by insects from any other source. ”

“ The galls mature in late July and, as the plants begin dying off in September, the diried galls drop to the ground where they overwinter, being in large part decayed by springtime. The galls are heavily parasitized. The insects mature in the fall and overwinter as adults, not emerging, however, until the following April or May. Adler proved, by experimentally raising successive generations, that there is no alternation of generations with the species and, since the male is unknown, it is likely that reproduction is regularly agamic, the eggs never being fertilized. ”

“ The accounts of the life histories of most of the others bring together for the first time information that has been scattered through a wide range of literature, much of which has not been available to the general student. It is my aim to supply complete bibliographies, redescriptions of adults and galls, detailed records of distribution, etc., and all the biological data available for each species. ”

“ The introduction of Rhodites rosæ and R. mayri, of roses, is easily understood, but the successful introduction of Aylax glechomæ and of A. taraxaci (not yet rerecorded from Europe, but since the dandelion is of European origin it is probable that the gall-wasp is also introduced) upon herbaceous plants is more surprising.
This species is, in many respects, very distinct from and more specialized than other members of the genus Aylax. ”

“ The gall of Andricus palustris palustris is one of the best-known of the galls of early spring, appearing abundantly on red oaks of many species, often before any leaves have appeared. They often crowd closely on the flowers of the oaks. When the galls first appear they are solid, with the larval cell distinct but entirely connected with the outer walls of the gall ”

“ Indoors, mold is almost certain to prove a problem. The use of earthern flower pots prevents too much moisture accumulating in the sand, and such receptacles for that reason are preferable to glass jars, but in the pots the emergence of the insects is not so easily observed. Galls that are to be kept over winter or for a long time before the insect matures may be kept in earthen pots until the approach of the date of emergence. ”

“ Bassett states that the insects may mature the following spring or may remain in the galls until the second or even third spring before they emerge. He found them emerging May 4 and ovipositing in the young buds of the oaks.
Bassett's observations of this species finally led to the first absolute proof that heterogeny occurred in the Cynipidæ. A detailed account of the discovery has been given on page 324. Adults have been bred from galls of both generations and each of these have been observed to oviposit to produce the galls of the other generation. ”

“ This connection was finally established when C. V. Riley, in the spring of the same year in which Bassett found the producer of C. operator, bred the adult from the acorn-gall. It was identical with the producer of C. operator. The fact of alternation of generations in the Cynipidæ was thus completely proved. [2]
Meanwhile, B. D. Walsh (1864) had reported in great detail the discovery of two very different forms of adults, one agamic and the other bisexual, emerging at different times of the year from very similar if not identical galls of Amphibolips confluens. ”

“ I have been successful in obtaining several adults. Mr. Lewis H. Weld and Wm. Beutenmüler have kindly confirmed my experience by similar records from their own observations, July 12 to July 30 being the emergence dates from their breedings. It is not likely that Riley's insects, found ovipositing three months earlier than clavula emerges, could be that species. I have no doubt that there is an error in Riley's report and that Bassett's observations of this species are. ”

“ The discovery of heterogeny in the Cynipidæ dates from an observation reported in 1864 by Homer F. Bassett, librarian in the town of Waterbury, Connecticut, and a student whose long series of observations of gall-wasps were made with a degree of painstaking care unmatched by any other worker with the family. ”

“ It is not desirable to have the plants indoors, for they do not develop at normal rates under these abnormal conditions and the insects will not attack the plants unless they are at the proper state of development. Wild roses and blackberries are easily transplanted, but it is profitable to secure nursery-grown oaks of several species, four or five years old, for the work. These should be growing thriftily before experiments are started, or else galls will probably not be obtained. ”

“ It is to be expected that under such conditions the females are often not fecundated but, nevertheless, the eggs of such individuals will grow parthenogenetically. This was very positively proved by Adler (1877) , who secured galls from eggs he had observed to be laid in the plant. He conducted extensive experiments with this species; in four different years he obtained similar results, rearing three generations in direct succession. obtaining galls and adults in each case exactly like those of the parent generation. ”

“ Undoubtedly the most satisfactory means of rearing the adult wasps is to place the galls on an inch or more of moist sand in a low glass jar at least four or five inches in diameter. The moisture thus supplied keeps the galls from drying out and dying; but the galls should not be piled in too deeply or those on top will not mature and those on the bottom will rot. ”

“ Of thirty-seven of the wasps which I have bred, thirteen. i. e., 35% of them were males. which is a higher percentage than that known from other species of the genus. However, incomplete observations on other breedings I have made would indicate a much lower percentage of males to be more nearly normial. The number of parasites obtained from these galls is extremely high; I have found them to constitute about 90% of all the insects bred—another instance of the ineffacacy of highly developed "protective" devices. ”

“ Legs: dark brown, hairy, yellowish at the joints, and on all the tarsi and on the tibiæ of the first and second pairs of legs. Wings: large, much longer than the body, clear; veins clear brown; areolet large; cubitus reaches the basal vein; radial area completely open on the margin; first abscissa of the radius angulate, the angle little more than a right angle but the apex high upon the vein. Length: 1.2-2.0 mm.
Male—Differs from the female as follows: head, thorax, and abdomen reddish to light piceous, the antennæ and legs entirely yellow ”

“ Paper bags of several sizes are readily available means of separating the galls in the field but, if extensive collecting is to be undertaken, it is preferable to make cloth bags, which are much stronger, take up less room, and may be more securely tied at the top than paper bags. ”

“ Similar experience had been had by all the students of gall-wasps and Giraud is quoted (Lichtenstein, 1881, p. xi) as remarking "Il a y dans ces Cynipides agames un mystère dont la découverte fera la gloire d'un homme." ”

“ Scutellum rather circular, rugose, the two foveæ broad, deep, shining but sparselv rugose, separated by only a fine ridge; pronotum finely punctate-shagreened, the mesopleurae finely shagreened to striate ventrally. Abdomen: rich rufous, brigbter basally, darker apically and dorsally, essentially smooth and shining, very microscopically punctate; the second segment covering two-thirds of the abdomen; the sheaths of the ovipositor pointing almost vertically. Legs: rather uniformly rufous brown; the tarsal claws darker, simple. ”

“ The points at which ovipositioin was made by the igntotus females were carefully marked and kept covered by gauze bags for almost a month and a half. The galls produced were first seen about the first of September, i. e., over a month and a half after the eggs were laid, but the degree of development of the galls indicated that they had appeared possibly two weeks earlier. ”

“ From my first lot of material I bred six females and seven males, and Cameron reported (1889) a similar experience. But other galls will give no males at all, indicating a great variation in the eggs laid by different individuals. The final average gives between one and two per cent males, and the observations of several workers (Adler, 1888; Cameron, 1889; et a!.) ”