II. Jefferson’s Notes on the Hessian Fly
[24 May-18 June 1791]
Conrad Lasher. 16. miles above Poughkeepsie. The Hessian fly remains on the ground among the stubble of the old wheat. At ploughing time for sowing the new crop they rise in swarms before the plough horses. Soon after the wheat comes up they lay the egg in it, of the size of a nit, and will crack like it. He supposes the old fly dies in the winter. In the spring they begin to grow. [I saw them just below the highlands on the 21st. of May in the worm state, about as long as a grain of rye, and one third it’s volume.1 White, smooth and transparent.] In June the Chrysalis bursts and the insect comes out, brown like a flax seed, a little longer, and with wings. The egg is found from the joint nearest the ground. He has counted 120. on one stalk, always under cover of the blade. The stem decays in that part, turns yellow, the blades become erect,2 and the plant dies. The farmers have found a remedy in what they call the new sort of wheat which is a white bearded wheat equal in quantity and quality to any kind they ever tended. It has a more vigorous stalk. He tried by highly dunging a piece of ground to give the old kind of wheat vigour enough to resist. For a while it promised fair, but the insect got the better at length and he made no more from that than any other. They are never in the grain or chaff. He thinks the fly does not generally remain in the straw when carried to the stack. Yet in one instance on threshing a stack in the spring, there were some found in the straw. He thinks they had no wings and consequently thinks they were dead. They have two wings naturally. The fly harms nothing.
The crop of the growth of 1785 was the first attacked. However that year they made a good deal. In 86. they destroyed all. So also in 87. and 88. These were the three years of it’s principal rage. In 1789. his crop was of the new wheat. In 90. he had no insect, nor is there any this year 91. His neighbor who continues the old wheat had some flies in 89. but not so as to injure his crop. He never saw an instance of it in the new wheat but it has attacked rye a little. But never any thing else that he knows of.
Pulvar. 23. miles above Lashar’s. The fly came first in 1787. into this neighborhood and destroyed the crops of 87. 88. 89. The people got the new sort of wheat which had a stronger stalk. Some tended that and the old kind at the same time. The old would be all destroyed and the new a little touched. Generally from 5. to 20 worms to a stem. The spring wheat more totally destroyed than the fall wheat. It attacked rye a little, oats a very little. There were a very few flies in 90. None this year 91. There would seem to be the best prospect possible of a good crop and then the moment it was getting into the ear it would all fall. The old kind of wheat is now rid of them. The worm is at first white, then becomes brown and a little bigger than a flea, then it bursts it’s case and comes out a fly with two wings about the beginning of June.
Kenderhook. Shethar. A field of rye which he sowed in the spring for pasture was totally destroyed. In 1788 was the first mischief he had done. Not certain if any fly appeared the year before. They prevailed little here when at the worst. He thinks that they never destroyed above one tenth taking the neighborhood in general. All gone now.
Moore. 8 miles from Albany. The fly was first seen in 1787. A few only. 1788 they did the most mischeif. In 1789 less. In 1790 they were only in two or three places and very few. None this year. Some persons insist on having found the fly in their stacks in the spring when they went to threshing. Others suppose them mistaken, and that it was some other fly. [This proves that but a few at any rate survived winter.]
Albany. Genl. Schuyler. There might perhaps be some few in this neighborhood in 87. but in 88. about 1/10 of the wheat of the neighborhood was destroyed. In 89 much less. Perhaps none in 90. This year certainly none.
Waterford. Gregory. First appeared in 88. Then the most mischief. In 89. very few. None since
Benjamin. 11. miles above Waterford. Same exactly as Waterford.
Still-water. Dr. Willard. 15. miles above Waterford. The principal mischief was done in 1788. He has heard that a few were seen in 1787. There was very little injury in 89. None since.
Saratoga. Mr. Schuyler. He understood a few were seen in 87. In 88. they injured the Spring barley and nothing else. In 89. they did the same as to Spring barley but in a still less degree. None since.
F[ort] Edward. The fly was known here in 88. and 89. but not enough to do perceptible damage.
Sandy hill. 2 miles above. do.
F[ort] George. Never here at all.
Cambridge. Had a few in 1789. 90. Have heard of some this year, but never did any sensible injury. They showed themselves rather more in Spring grain. Colvin.
Bennington. Had a few in 89. 90. Have not heard if there are any this year. Never did any injury. Dewey. Fay. Robertson.
Pitsfeild and Dalton. In 88 first known but not to do mischief. In 89. about one third of the wheat in the neighborhood destroyed. In 90. a few but no harm. This year have not heard of any.
Northampton. In 88. first known but did no harm. In 89 rather more, but not sensibly injurious. In 90 still a few. This year none.
W. Springfeild. Some were seen in 87 but did no injury, yet it spread such an alarm that few people sowed wheat. They substituted rye in their grounds. The few who sowed wheat however had as good as ever in 88. Then in 89 every body sowed again and no harm done. Some say there are a few this year.
[Ju]ne 10. Sidon hill near Middletown. They appeared here first in 84. and did extreme mischief that year and 85. and 86. that the informant left off sowing wheat in 87. 8. 9. In 90 he had a good crop of the sowing of 89 and no fly. This year he knows of no fly.
Stranton’s 5 miles from Guildford. They appeared here first in 1786. but did not very much injury that year. But every year since they have destroyed ⅓ or ½ and are as many this year as ever. They got the new kind of bearded wheat last year and this year a small quantity. They have not injured that more than rye. They have sometimes touched the rye a little. Have not meddled with oats.
[G]uilford. They came here about 86. and have done much mischief in the old wheat.
Oyster pond point. They came here about 86. Have done much mischief ever since. The yellow bearded wheat has been introduced. That is strong and attacked about as much as rye is. If that wheat gets the start they cannot hurt it. Has heard of none this year. Rufus Tupple.
Southold. 15 miles from Oyster pond point. Mrs. L’hommedieu’s. The fly came here in 85. and destroyed the crops of that year, 86. and 87. Then they got the yellow bearded wheat which resisted them in a great degree but not entirely. But they got a piebald wheat from Goshen which they never touched and it is a fine white wheat. Besides this the farmers finding that the fly destroyed all weakly wheat got into the practice of manuring highly which contributed very much to prevent the ravages of the fly by making the wheat too vigorous for them: so that by the improvement of manure the country really has been benefited. In 88. 89. 90. no mischief done worth speaking of but in the old lands and old kinds of wheat. In these there are some this year.
The fly lays a maggot (not an egg) in the young wheat near the root. This becomes in the winter and spring a cocoon. Resembles flax seed and eats itself out of it’s coat in May or June and comes out a fly. This fly appeared first in Flatbush near where the Hessians landed and the year after they landed, and they have travelled about 20 miles a year, more or less according to the winds.
The yellow bearded wheat was foreign wheat taken by the British (not known from whom) a bushel of which was sowed by a miller accidentally.
The fly cannot go Westwardly because repelled by the Westwardly winds.
Colo. Dearing of Shelter Isld. has been particularly serious in his observations on this fly.
Riverhead. Griffin. Fly was never at this place, nor for 4 or 5 miles all around it. Beyond that distance in every direction a plenty. The reason unassignable. This is 18. miles from Southold.
Morichie’s. Downs’s. Came into this neighborhood in 85. He had a very few that year, but not to do sensible injury. Has had none since. This neighborhood for some miles never affected by it. Cannot account for it.
Genl. Floyd. He observed that the fly travelled from West to East about 20 miles a year, but he went a journey N.E. and found they travelled much more in that direction because it was going before the wind, for at the season of their being able to fly the S.W. winds prevail. This is the reason they go slowly to the Westward.
Terry’s. 22 miles from Genl. Floyd’s. The fly came here in 85. and destroyed some fields of wheat entirely. However they have never prevailed on the S. side of the island near as much as on the N. side. They have for many years sowed the bearded wheat. No fly this year.
Hamstead. A few here this year.
Flushing. Prince. This insect first appeared at this place. The Hessians were stationed here in 76. and in 77: the insect appeared. It was very slow indeed in it’s first extensions, not getting beyond the limits of this neighborhood for some years. He confirms the account of the origin of the yellow bearded wheat given by L’hommedieu. It was first sown by a miller in this neighborhood.3
Richmond. They came here a year or two after the war. They destroyed 3 crops. He (Turner) thought that their general period every where was of 3 years. The bearded wheat not hurt by them.
South Amboy. They came here about 2 years after the war. Have made general destruction ever since among the old wheat, but not the bearded. This is a sandy country and but little wheat raised.
A smith’s shop 6 miles from S. Amboy. They came here in 83. or 84. and have destroyed 7 crops of the old kind of wheat. There have been fewer for 3 years past tho there are still some. He saw this year a feild sown part with the old wheat, part the bearded. You might trace the very furrow where they changed. The old destroyed, the bearded not hurt.
Williamson. 14. miles from S. Amboy. The last good crop of wheat he has had was the summer after the peace. The year following all was destroyed, and so afterwards every year in a greater or less degree. They fluctuate, prevailing less some years, more the next. Last year for instance, they did little injury here. This year they will destroy two thirds. The bearded wheat is attacked, but less than the other. If wheat be sown early in the fall they will destroy it in the fall. It is better therefore sown late. About a month ago he saw some of the insects in the green chrysalis, others in the brown and the empty chrysalis of others, the fly having eaten itself out. It is when the chrysalis has turned brown that it resembles flax seed.
I found here some of the cocoons full and some empty. They were all of the size and color of flax seed.
Allentown. 14 miles from Burlington. This the 5th. harvest attacked here. ⅔ will be lost this year, to wit all the old kind of wheat and a little of the bearded. Last year the loss was still greater. The bearded wheat produces less, is more difficult to cut and thresh, and the chaff is useless.
MS (DLC: TJ Papers, 69: 11907–9); the first part of the notes was written by TJ in four columns on recto and verso of a folded address cover, postmarked and addressed “Hble Thos. Jeff[e]rson Philadelphia” in hand which appears to be that of Barbier Demarais, whose letter of 7 May 1791 was received by TJ on the day he departed from Philadelphia. The second part, from 17 to 19 June, was added to the verso of TJ’s Journal of the Tour (see note 3 below and note to Document i). Brackets for first and second passages in MS.
One document on TJ’s investigation of the Hessian fly is an undated anatomical description of the insect which has hitherto been assigned to 1791 but which was almost certainly written in June 1792. This consists of a single leaf and has the following at the top of its verso (DLC: TJ Papers, 69: 11909):
|June 1.||Mr. Williams brought several
stalks with the Chrysalis of the
Hessian fly in them, most were
of the flax seed colour, one only
was pale green.
|5.||a fly found hatched in the morning.
qu: how long[?]
at 9. aclock laid eggs.
|14.||3. do. hatched.|
From this it is clear that TJ was conducting an experiment over a period of two weeks and that this could not have occurred while he and Madison were on their journey. On 1 June 1791 they were at the head of Lake George where the fly had not been seen in two years. The “Mr. Williams” who brought TJ the wheat stalks was probably Jonathan Williams, who in the spring of 1792 was in Philadelphia and who attended meetings of the American Philosophical Society when TJ was present. At that time the Committee of the Society of which he was chairman drew up and published its series of queries calling upon all persons having information about the natural history of the insect to communicate the same to TJ. TJ’s anatomical description of the fly must therefore have been written at that time. It is given as a note to the Committee’s questionnaire, which is dated 7 June 1792 (see note to that document; also TJ to Thomson, 20 Apr. 1791).
1. TJ first wrote “… grain of wheat and half as thick” and then altered the passage to read as above.
2. TJ first wrote “… the blades stand straight up” and then altered the passage to read as above.
3. At this point TJ wrote “Contd.” The continuation of his notes on the Hessian fly, consisting of all that follows, was written on the verso of his Journal (see note to Document i).