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AMERICAN HOMES AND GARDENS 



September, 1905 



A Little Friend of the Rose 



By S. Frank Aaron 



'// can never be too strongly impressed upon a mind anxious for the acquisition of knowledge that the commonest things by ivhich -ive are surrounded 



are deserving of minute and careful attention. " — R.ENNIE. 



3HE flower-loving 



insects are all 



friends in need; 



but the unhon- 



eyed flowers also 



have their insect 

 friends, not agents of fertilization 

 only, but protectors and cham- 

 pions that tight the battles of those 

 that must depend on the flower 

 stems and leaves and buds to sur- 

 vive. But though the flowers are 

 voiceless, they tell us with none the 

 less eloquence what their enemies 

 are and how they suffer by them. 

 Ask the rose. The withered, 

 skeletoned leaves proclaim the 

 enmity of the saw-fly slug; eaten 

 leaves and others folded over tell 

 of the larvae of the golden-winged 

 tortricid moth; while cankerous, 

 eaten buds and flowers denounce 

 the rose bug, the aphides, that 

 crowd the green stems and leaves 

 of the newer growth and swarm 

 all over the tender buds. 



Annihilate the aphides upon a 

 dozen stems of a thrifty bush and 

 keep others off ; then let a dozen 

 others go full of the lice, and 

 watch results. The number and the 

 beauty of the blossoms will be the 

 answer. Now, Nature generally makes a wise effort to strike 

 a proper balance, and though we have heard this denied con- 

 cerning the potato beetle, yet it is true, more or less. Thus 

 she has furnished several antidotes 

 for the aphis; if she did not the 

 little pests would become a nuisance 

 indeed, past all calculation. This 

 salutary purpose is effected by the 

 several larvae of the syrphus fly, the 

 lace-winged fly, the ladybug and a 

 number of very small Hymenopter- 

 ous parasites. Of these latter the 

 most interesting and the most com- 

 mon is the pretty little fly known to 

 the scientists as Praon, which may be 

 called the cocoon-making parasite of 

 the aphis. Any one with sharp eyes 

 may discover this little friend of the 

 rose at work, and may follow, with a 

 little care, its complete life history. 



At the time when the plant lice 

 are thickest a small insect resembling 

 a miniature wasp, or an ichneumon 

 fly, which it really is, may be seen 

 making its way among the fat 

 aphides, moving leisurely and with a 

 dignity quite beyond its size, for it 

 usually is not longer than an eighth 

 of an inch. It approaches one of 



Little Friendsof the Rose atWork among a Herd of Plant Lice 



^ Any one carefully and frequently inspecting the rose bushes and the aphides 

 gathered on the green and tender new growth may see enacted the small 

 tragedies between the parasite fly and its victims. 



iniature Pig Sticking, as seen through Magnifying Glass 

 •I The fly of the rose aphis parasite stinging and laying its egg in the 

 body of a rose aphis. The plump little plant lice look like hybrids 

 between a verdant goat and a green pig and they get about much like 

 overt at swine. Their inactivity permits them to be readily attacked, 

 and their only attempt at defense is in wagging their bodies from side 

 to side, which sometimes for a moment disconcerts the parasite fly. 



the larger aphides and touches it 

 with its antenna,' as a means of 

 certain identification, scent far 

 outranking sight in such matters 

 among insects. If this were an 

 ant the aphis would respond with 

 a liberal supply of the coveted 

 honeydew, but knowing friends 

 trom toes it now slings its body 

 from side to side, quite violently 

 indeed for such a lethargic crea- 

 ture, and the little fly is pushed 

 aside. Not liking this it moves 

 on to another or smaller aphid 

 with a less vigorous movement, or 

 pausing a moment attacks the 

 same aphis again, with perhaps 

 better results. Choosing its posi- 

 tion deliberately and carefully, 

 with its slender, stiltlike legs lift- 

 ing it high, it widely straddles its 

 victim, its fore legs often resting 

 on the aphid's back, its slender 

 body and long antennae much 

 jostled by the agitated plant louse. 

 But now the fly is not to be dis- 

 lodged. Its keen, swordlike ovi- 

 positor protrudes from its sheath 

 and in a moment is thrust deep 

 into the back of the plant louse, 

 and is held for just another mo- 

 ment, until an egg, so tiny as to 

 pass through the slender organ, is deposited into the very 

 interior anatomy of the rose pest. Then withdrawing, the 

 fly straddles off and proceeds at once to convert another aphis 



into an incubator, and so on, until 

 no doubt the egg supply, perhaps 

 fifty or more, becomes exhausted. 



Of course the aphis so treated 

 does not die at once, else Nature's 

 plan would miscarry. It lives and 

 goes on feeding and maintaining the 

 same stiff and seemingly contented 

 attitude for a little while. Mean- 

 time the egg hatches a minute, white, 

 maggot-like larva, and this at once 

 begins feeding on the soft muscular 

 tissues of its host. Some little time 

 is required for the larva to complete 

 its growth — five or six days during 

 very warm weather, longer when it 

 is cool. With an instinct that has 

 ever been a marvel to the naturalist 

 the little larva does not touch the 

 digestive organs, the vascular sys- 

 tem or the more important nerves 

 for a period, thus permitting the 

 aphis to live and feed until the ap- 

 petite and growth of the parasite 

 warrant it to eat all before it. Then 

 the aphis dies, of course, and rapidly 



