42 REPORT OF No. 19 



has become so extensive and well-nigh universal, that the supply of the seed 

 is becoming more and more a matter of paramount importance. The in- 

 creased use of clover is indicated by the decided advance which has already 

 taken place in the market price of the- seed ; and from this circumstance it 

 is less than ever before keeping pace with the demand for it. It would seem 

 the natural conclusion that interest should be stimulated in the production 

 of such a remunerative commodity, and the fact that it has not been to a 

 sufficient extent to control the price, suggests that there may be some off- 

 setting factors to be taken into account — which is indeed the case. A re- 

 ference to the annual reports of the Bureau of Industries of Ontario, reveals 

 almost invariably a more or less unsatisfactory yield of clover seed. Further- 

 more, in examining carefully a large number of heads of clover here this 

 fall, it was found that only 42 per cent, of the florets had produced seed, 

 and undoubtedly the percentage is frequently much lower than it is this 

 fall. It is not unusual for the yields to be so low as to render the harvest- 

 ing unprofitable. In fact so uncertain and precarious a crop is it, that on 

 a commercial scale it is a regular crop in only comparatively limited sec- 

 tions of Ontario, and in the other Provinces of the Dominion is but little 

 grown. This general uncertainty of obtaining a reasonably full yield of 

 seed is due to various causes. The plants on heavy or undrained land may 

 be weakened by winter heaving; or on light soils their growth may be 

 f^hecked by summer droughts. The soil in. some sections is so deficient in 

 its retentiveness of moisture, that it is only in exceptional years that any 

 considerable aftermath is produced. Insect ravages, and imperfect ferti- 

 lization are two other causes. In the present article we proteose to deal 

 only with the two latter factors, showing how the presence of certain in- 

 sects, and the absence of certain others, combine to affect adversely the 

 yields of clover seed. 



There are fully a dozen insects which do appreciable injury to some 

 part or other of the red clover plant, but by far the most destructive to the 

 seed is the Clover Seed Midge (Cecidomyia legmninicola). This insect has 

 gained a wide range in America, and every year causes an immense depre- 

 ciation, in the yield of seed. It is estimated that the loss in Ontario ranges 

 in various localities, all the way from 25 to 75 per cent. In an examina- 

 tion of 50 heads of clover late in September, when in all probability some 

 of the midges had already escaped, 164 of their larvae were found. 



The insect which is responsible for this destruction is a minute two- 

 winged fly, which appears in May or early June, and lays its eggs on the 

 developing heads of clover among the bristles which surround the young 

 florets. From these eggs, which are so small as to be almost invisible to 

 the naked eye, the larvae hatch and find their way down the opening corolla 

 tubes to the future seed at the base. Small as they are they may be readily 

 seen if placed on a white surface, and appear variable in color from whitish 

 to orange-red. They feed on the doughy seeds until fully-grown, about 

 the last week in June, when they emerge from the florets, and dropping to 

 the crround transform to the pupal stage just below the surface. The pupae 

 develop to the adult flv in time that these may lay their eggs upon the second 

 growth of the clover for another brood of the maggots. Thus both crops 

 of clover are attacked, and after the damage is done the midges remain to 

 go into hibernation until another year's supply of food is ready. 



Tn order to combat this pest, it is only necessary to bear in mind the 

 date at which the first brood is likely to pupate; and by cutting the crop a 

 little in advance of this time destroy the whole brood, or by pasturing until 

 danger from the first brood is past, prevent altogether the deposition of the 



