Plant Sanitation- 



142 



tAUOUST, 1909 



work be in the hands of a trained 

 entomologist who knows his work. The 

 latter may not introduce so many 

 insects, bat there is a very much greater 

 possibility ot their being of use. 



The ideal introduced parasite is one 

 that can be bred in a large State or a 

 private insectarium in sufficient num- 

 bers that it can be distributed just at 

 the critical time when the particular 

 pest it destroys is in evidence, which, 

 when it is once liberated in the orchard 

 and garden, can establish itself against 

 all comers in sufficient numbers, adapt 

 itself to its surroundings, and, when 

 its food supply is exhausted or has 

 reached the vanishing poiut (a natural 

 consequence if it is to be an effective 

 parasite), will either find some other 

 insect to devour, or will hibernate until 

 fresh supplies come into existence. 



The discovery of such an admirable 

 parasite has been proclaimed again and 



again; but it is much to be regretted 

 that it has become the habit of entomo- 

 logical collectors to enlarge upon the 

 great value of their discovery before 

 the insects have reached their desti- 

 nation, and to proclaim, not what it has 

 done, but what it is expected to do 

 when introduced into its new home. 



Its admirers should be perfectly hon- 

 est ; and if a friendly introduced insect 

 from which, rightly or wrongly, great 

 things had been expected turns out on 

 further trial to be a failure, they should 

 say so ; and they should never proclaim 

 results for a parasite till those results 

 have actually been proved in its adopted 

 country, for the wisest can never be 

 sure of the results of any experimen t. 



Economic entomology is a great 

 commercial science, and those at work 

 for its far-reaching interests could do 

 it no greater harm than by misleading 

 or improved statements. 



MISCELLANEOUS PESTS. 



THE PROPAGATION OP 

 LORANTHUS. 



(Extracts from " Observations on the 

 Loranthacece of Ceylon," by F. W. Keeble. 

 Trans. Linn. Soc, Vol. V., Pt. 3, 1896.) 



Many Cingalese members of the genus 

 Loranthus have large and conspicuous 

 flowers ; in such the corolla is brightly 

 coloured, more or less tubular, and 

 generally 5-lobed. 



In many of the Cingalese species a slit 

 occurs in the corolla-tube, whereby, at 

 the time of opening, the upper part of 

 the tube by growth of its inner surface 

 opens out laterally, so that all the five 

 lobes, whose inner surfaces also at the 

 same time grow more rapidly than their 

 outer, come to stand in a row, and the 

 stamens also which arise from the bases 

 of the lobes similarly stand side by side. 



In enquiring into the significance of 

 these slits it must be remembered that, 

 as other observers have already shown, 

 these tube-flowered Loranths are bird- 

 fertilized. My own observations confirm 

 this, for in Ceylon the common honey- 

 sucker, a species of Nectarinia, is always 

 to be found, especially in the early 

 morning, visiting these flowers. 



I shot some of these bird? which were 

 busy in a Loranthus bush and found their 

 beaks covered with pollen. Whether 

 other birds also act as carriers of Loran- 

 thus pollen I could not determine. Now, 

 birds are less precise in their methods 



than butterflies, and the pollen-carriers— 

 their beaks— are much larger and by no 

 means symmetrical. By the spreading 

 slit or throat a bird's beak has ample 

 space to reach the nectar which fills the 

 bottom of the tube. Thus the natural 

 slit saves the flower to some extent, but 

 not wholly, from being torn. Further, 

 the arrangement of the stamens side by 

 side, rendered possible by the opening 

 out of the part of the corolla-tube above 

 the slit, has the important effect of ex- 

 posing the dehiscent surfaces of all five 

 stamens to one side (the upper) of ohe 

 birds's beak, so that the pollen is rubbed 

 on the whole of that surface. Since the 

 stigma, projecting beyond the stamens, 

 is so placed that it too will touch this 

 upper surface, it is clear that the con- 

 finement of the pollen to this surface, 

 effected in the manner just described, 

 tends to render pollination more certain. 



The most noticeable appearance in a 

 bush of L. loniceroides is the large num- 

 ber of fully mature flower-buds contrast- 

 ed with the number of open flowers. The 

 explanation is simple. The flower-bud of 

 L. loniceroides, though fully developed 

 in all respects, remains closed. If the 

 apex of the corolla of such a flower- bud 

 be gently struck, the lobes fly apart, 

 exposing stigma and ripe pollen-bearing 

 stamens. These lobes, once released, 

 continue, by growth of their inner sur- 

 faces, to bend backward till they are 

 reflexed on themselves, and there is no 

 doubt that fully-developed flower-buds 



