From a careful rearing and study of this insect in the office, and from correspondence with the Messrs. Coe, as well as from Mr. Smith's report, we may summarize the insect's history in America as follows:

The eggs are laid in the spring, in the flower end of the fruit, as soon as or even before it "sets." The fruit grows and soon assumes a somewhat distorted appearance, or, as Mr. Smith says, "an irregular, somewhat knobby " look, or occasionally seeming abnormally round. If one of these young pears be cut open, its interior will be found to be channeled and grooved, the seeds separated and eaten into, and the entire core disorganized. Surrounded by excremental pellets and partly imbedded in the flesh of the fruit will be found from ten to thirty little yellowish-white maggots, which, as they grow, absorb more and more of the pulp, usually, however, attaining their full growth before the interior of the pear has been entirely consumed. When full grown they leave the fruit either through the calyx end or through some crack or soft spot and drop to the ground, working their way underneath the surface.

The larvae (Fig. 1) progress, as do other species of Diplosis, by a series of skips or jumps, by which they fling themselves an inch or more in a horizontal direction. The anal end of the body is curved under until it reaches the posterior margin of the first thoracic joint, the anterior end of the body being also somewhat curved downward, and is then suddenly snapped straight with such force as to lift and throw the whole body.

Life History And Habits 11

Fig. I.

From observations made by the Messrs. Coe, it seems that after the larvae are full grown, or nearly so, they leave the fruit, preferably during a rainstorm, or are forced from it by the rain penetrating the cracks in the fruit. The following extract from a letter dated June 12, 1885, bears upon this point:

"Our men had gone over the orchard once, picking all that they could find, and were going over it a second time when a violent rain-storm obliged them to quit lor an hour or two. Returning after the rain they observed that a basket that had been left out in the storm with 2 or 3 quarts of the wormy pears was alive with the larvae, hopping about like so many fleas. They had all left the fruit and were trying to escape from the basket. Upon examination we found that the infested fruit on the trees had no larvae. So the work was not so thoroughly done as we had intended".

Mr. Smith's observations prove that the larvae reach the ground by dropping from the tree, after which they immediately seek to hide themselves beneath the surface. They burrow to a greater or less depth, depending upon the porosity of the soil, but rarely exceed an inch. They remain for a considerable time (just how long is not yet determined) in the naked larva state before commencing their cocoons, and then in the cocoons for another length of time before transforming to pupae (Fig. 2, c).

The cocoon is whitish, thin, but tough, oval in form, and covered with adhering grains of earth.

There is but one annual generation. The larvae which go into the ground about the 1st of June remain there, either as larvae or pupae, until the following spring. This is proven definitely by our observations at the Department. From a lot of pears received from Mr. Smith June 10, 1884, the larvae went into the ground almost immediately and the flies issued as follows, the earlier ones being influenced to premature development by the warmer temperature of the vivaria:

Specimens issued

January 9,1885.........


" 15, 1885...........


" 28, 1885...........


" 30, 1885...........




" 7,1885..........


Specimens issued

April 9,1885..........


April 10,1885.....


April 11,1885........


" 12, 1885..............


" 13, 1885..............


The Messrs. Coe were led to suppose that the insect might be double-brooded, by finding pears as late as August infested with similar larvae; but from pears sent August 31 for examination nothing but numerous specimens of a species of Droso-phila were bred, and these had doubtless been attracted by the diseased or rotting condition of the fruit.

In giving out the adult fly the pupa breaks through the cocoon and works its way through the earth to the surface, struggling until nearly its whole body is in the air and the anal end only is held in the earth. The skin of the thorax then splits longitudinally and the adult fly (Fig. 2, a) makes its escape.

Life History And Habits 12

Fig. 2.

Three specimens of an undetermined species of the genus Platygaster were found in the breeding jar containing the infested pears, on April 9 and 11, and had evidently been parasitic upon the larvae of the Pear Midge, although no parasited cocoons of the latter were found. No other insect was contained in the jar, and there is little doubt of the parasitism. As will be shown later, there is a strong probability of the importation of this midge from Europe, and this parasite may very readily have been brought over with it. There are more than one hundred described species of the genus Platygaster in Europe, the descriptions of many of which are inaccessible. Walker's species, of which there are sixty-nine, are very insufficiently described. Hence there will be great difficulty in determining this species, and we hesitate to describe it as new.

No better, simpler, or more satisfactory remedy can be devised, in the light of what we now know of the habits of this insect, than that used the last season by the Messrs. Coe, which is, to strip the fruit from the trees in an " off year " and destroy it either by burning after covering it with kerosene, or by feeding to hogs before the insects have a chance to escape. This should preferably be done about the middle of May, or before the larvae have attained full growth. So far as known at present the insect infests no other fruit than the pear, and it ought not to be impossible for the fruit-growers around Meriden to practically exterminate this pest in a single season. In 1884, this remedy was tried on the Coe place, but the insect reappeared in the spring of 1885, in greater numbers than expected, which showed that the picking was not done as thoroughly as supposed, or was done too late, or else that the insect had gained a good foothold in neighboring orchards in which the picking was not tried.

In a letter dated June 12, 1885, the Messrs. Coe give the result as follows:

" Our method seemed to answer for all practical purposes, as they had not come this spring in sufficient numbers to do damage by diminishing the crops. This is the bearing year for our orchards, and the trees all blossomed abundantly. The insect confined itself to its favorite pear in the main. None were found in Anjou or Seckel and few in other varieties besides the Lawrence. The 125 trees of Lawrence had perhaps one-sixth of the fruit infested".

That this insect has been recently imported from Europe seems quite probable, for the following reasons:

(1) Until this insect was found upon the Coe farm, no insect of similar habits was known in this country.

(2) An insect of almost precisely similar habits and of identical appearance (except for certain discrepancies which can be explained away) has been described by European authors, and, as early as 1831, did considerable damage to the pear crop in parts of Europe.

(3) In 1884 Mr. Coe said that some seven years since he imported a large lot of pear stocks from France, upon which were grafted American pears; prior to that time he had never seen the insects. A year or two afterward they were first noticed, but in small numbers, and since then have been on the increase. Mr. Coe is the only one in his section of the State who has imported pear stocks, and his farm was the first, and for some time the only one, infested.

[This is an abstract of a paper by Prof. Riley which appears in the recent Entomological Department of the report of the United States Commission of Agriculture. Those who desire to pursue the subject critically will find much fuller details at pages 287 and 288 of the Report. It promises to be an insect that will eventually assert an importance equal to the Curculio among plums, or the Codling Moth among apples. Some of the reference marks on the cuts refer to an account more in detail, which appeared in the official Government publication. - Ed. G. M].