PLY, HESSIAN. 



spring, they are prepared to lay their eggs on 

 the leaves of the wheat sown in the autumn 

 before, and also on the spring-sown wheat, tha 

 begins, at this time, to appear above the surface 

 of the ground. They continue to come forth 

 and lay their eggs for the space of three weeks 

 after which they entirely disappear from the 

 fields. The maggots hatched from these eggs 

 pass along the stems of the wheat, nearly t 

 the roots, become stationary, and turn to pupae 

 in June and July. In this state they are found 

 at the time of harvest, and when the grain is 

 gathered, they remain in the stubble in the 

 fields. To this, however, as Mr. Haven re- 

 marks, there are some exceptions ; for a few 

 Of the insects do not pass so far down the side 

 of the stems as to be out of the way of the 

 sickle when the grain is reaped, and conse^ 

 quently will be gathered and carried away with 

 the straw. Most of them are transformed to 

 flies in the autumn, but others remain un- 

 changed in the stubble or straw till the next 

 spring. Hereby, says Mr. Havens, ' it appears 

 evident, that they may be removed from their 

 natural situation in the field, and be kept alive 

 long enough to be carried across the Atlantic ; 

 from which circumstance it is possible that 

 they might have been imported' in straw from 

 a foreign country. In the winged state, these 

 flies, or more properly gnats, are very active, 

 and, though very small and seemingly feeble, 

 are able to fly to a considerable distance in 

 search of fields of young grain. Their 

 principal migrations take place in August and 

 September in the Middle States, where they 

 undergo their final transformations earlier than 

 in New England. There, too, they sometimes 

 take wing in immense swarms, and, being 

 probably aided by the wind, are not stopped in 

 their course either by mountains or rivers. On 

 their first appearance in Pennsylvania, they 

 were seen to pass the Delaware like a cloud. 

 Being attracted by light, they have been known, 

 during the wheat harvest, to enter houses in 

 the evening in such numbers as seriously to 

 annoy the inhabitants. 



"The old discussion, concerning the place 

 where the Hessian fly lays her eggs, has lately 

 been revived, in consequence of a communica- 

 tion made by Miss Margaretta H. Morris, of 

 Germantown, Pennsylvania, to ' The American 

 Philosophical Society,' of Philadelphia. The 

 following remarks upon it are extracted from 

 a report made to the same society, and pub- 

 lished in their Proceedings for November and 

 December, 1840. 'Miss Morris believes she 

 has established that the ovum (egg) of this 

 destructive jnsect is deposited in the seed of 

 the wheat, and not in the stalk or culm. She 

 has watched the progress of the animal since 

 June, 1836, and has satisfied herself that she 

 has frequently seen the larva within the seed. 

 She has also detected the larva, at various 

 stages of its progress, from the seed to between 

 the body of the stalk and the sheath of the 

 leaves. According to her observations, the 

 recently hatched larva penetrates to the centre 

 of the straw, where it may be found of a pale 

 greenish-white, semi-transparent appearance, 

 in form somewhat resembling a silk-worm. 

 From one to six of these have been found at 

 496 



FLY, HESSIAN. 



various heights from the seed to the third joint." 

 Miss Morris's communication has not yet been 

 published in full; but, from the foregoing re- 

 port, we are led to infer that the egg, being 

 sown with the grain, is hatched in the ground, 

 and that the maggot afterwards mounts from 

 the seed through the middle of the stem, and 

 having reached a proper height, escapes from 

 the hollow of the straw to the outside, where it 

 takes the pupa or flax-seed state. The fact 

 that the Hessian fly does ordinarily lay her 

 eggs on the young leaves of wheat, barley, and 

 rye, both in the spring and in the autumn, is 

 too well authenticated to admit of any doubt. 

 If, therefore, the observations of Miss Morris 

 are found to be equally correct, they will serve 

 to show, still more than the foregoing history, 

 how variable and extraordinary is the economy 

 of this insect, and how great are the resources 

 wherewith it is provided for the continuation 

 of its kind." (Harris.) 



Dr. B. H. Coates of Philadelphia, whose at- 

 tention has been recently drawn to the Hessian 

 and other flies destructive to wheat crops, 

 states that a number of examinations made in 

 the vicinity of Philadelphia during the summer 

 of 1841, snowed the presence of a pale yellow 

 larva in the hollow of the straw of wheat, 

 which he considered as proved to be the same 

 with that which is ultimately converted into 

 the Cecidomyia Destructor of Say, and the 

 Hessian fly of our cultivators. In many in- 

 stances, "communicated to him by Miss Mor- 

 ris," referable, perhaps, to a peculiarity in the 

 season, the animal went through all its stages 

 before escaping from the cavity ; " thus afford- 

 ing," says Dr. Coates, "irrefragable evidences 

 of the identity of the species." In no case 

 known to Dr. C. had any thing resembling a 

 caterpillar or maggot, or any thing apparently 

 capable of locomotion, been found under the 

 sheath of the leaf: the body observed was 

 always immovable and fixed in a depression of 

 the straw. (Proceedings of the Jim. Phil. Soc.) 



"Various means have been recommended 

 for preventing or lessening the ravages of the 

 Hessian fly; but they have hitherto failed, 

 either because they have not been adapted to 

 the end in view, or because they have not 

 been universally adopted; and it appears 

 doubtful whether any of them will ever en- 

 tirely exterminate the insect. It is stated in 

 the before-mentioned report to ' the Philoso- 

 phical Society,' that Miss Morris advises ob- 

 :aining ' fresh seed from localities in which 

 the fly has not made its appearance,' and that 

 by this means the crop of the folio wing year will 

 je uninjured; but in order to avoid the intro- 

 duction of straggling insects of the kind from 

 adjacent fields, it is requisite that a whole neigh- 

 bourhood should persevere in this precaution 

 for two or more years in succession.'" (Harris.) 



It seems to be generally admitted that the 

 variety of wheat called Mediterranean, intro- 

 duced a few years since into the United States, 

 where it is now extensively cultivated, resists 

 the attacks of the Hessian fly. Hence it may 

 be sown very early in the fall, long before il 

 would be safe to sow the common varieties, 

 by which another great advantage is gained, 

 in its escaping the rust and mildew so apt to 



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