341 



CASSELL'S POPULAR GAEDENINa. 



Saw-flies.— Next to the caterpillars of the moths, 

 and hardly second to them in destructive force among 

 the Eoses, are larvae of the Saw-flies. There are many 

 species, such as Tenthredo {Cladius) difformis, T. agilis, 

 T. zona, T. eincta, and T. rosarum (Fig. 53). The 

 Saw-flies, as their name impUea, do not cease to 

 injure the Eoses after growing out of the larva 

 state. The fly, with its saw-like implements, cuts 

 and carves the Eose branch or leaf about as it 

 lists, now cutting a longitudinal section along the 

 bark of the young twig, just like a slit for budding 

 with the exception of the cross, or T-cut ; and yet 

 the slit, on examination, is found to be anything 

 but regular or smooth ; a series of atoms are chipped 

 out with the intervening chips left in, with the re- 

 sult that each egg, when laid, has its own separate 

 cell prepared thus for it by the saw-like appendages. 



In other species the eggs are laid across the twigs, 

 little niches being rather chopped than sawn out for 

 their reception. The eggs are then glued in position 

 in true carpenter-like fashion. They also grow after 

 deposition, a rare phenomenon among eggs, and one 

 that would be welcome to paterfamilias in winter 

 , among those of fowls when they average twopence 

 each. The larvae, so soon as hatched, of some of the 

 species, such as T. cineta, immediately make for the 

 pith of the Eose, and work down into and through 

 it, carrying disease and death to the leaves on their 

 passage. So soon as they reach the harder and older 

 wood of the Eose, they are brought to a forcible stop, 

 change into the pupa state, and rest in safety, un- 

 less the shoot is carefully cut hack to the old wood, 

 with the pith intact, and all above that point imme- 

 diately burnt. Others, such as T. rosarum, feed 

 chiefly on the leaves or part of the leaves, that is, 

 the soft cellular tissue, leaving the harder veins like 

 skeletoned leaves as relics of their destructive power 

 and fastidious taste. The larvse are very small, 

 pale yellow and whitjsh. This is a double-brooded 

 species, the larvae appearing in June and also in 

 September ; as is 2". (Athaka) rosa, which has broods 

 in June and July. The latter lays its eggs on the 

 upper surface of the leaf, and they either lack the 

 power or the will to turn over. Hence, they re- 

 move the top covering and surface of the leaf, and 

 seldom pass below the under side or rib. In 

 T. difformis there is a considerable di£Eerence be- 

 tween the two sexes, hence probably the name. This 

 species is also perhaps more timid and easily de- 

 tached than most of the others. It has been said 

 also to afEect standard Eoses more than any of the 

 other species. The fly is only a sixth of an inch 

 long, and about a third of an inch broad across the 

 extended wings. The larva is pale green, about half 

 an inch long and stouter in proportion. The flies 

 (and the majority of them) are a mixture of yellow 



and black. They generally roU themselves up in 

 a ball when disturbed, and this, combined with the 

 fact of their di-opping promptly when the bushes or 

 trees are agitated, points to a ready mode of de- 

 struction, by sharply tapping and shaking the Eose 

 plants and leaves ; the shoots should also be collected 

 and burned so soon as they reveal traces of the 

 Saw-flies. The flies are far from being so active as 

 some, and many of them might be caught and de- 

 stroyed. Nauseous and poisonous devices are also 

 as effectual against the larvae of Saw-flies as the 

 caterpillars of the moths. 



Tlie Eose-leaf Miaer {Tinea Euficapitella).— 

 ^This tiny insect is only about a sixth of an inch 

 long, and slender in proportion. This, unlike the 

 larva of the Saw-fly, eats the upper or under 

 surface of the leaf, not any part of its substance 

 bodily, but channels its own way in mere lines 

 through it, and when full-grown or f uHy fed, about 

 the end of the season, it crawls out, makes its 

 way down the stem, and flmds a snug place to 

 change into a chrysalis, to await the completion of 

 its life in a moth and egg - layer, next spring. ' 

 Leaves thus tunnelled wiU reveal the injury, and 

 also the insect, if merely held up between the eyes 

 and the sun, and should be immediately picked ofE 

 and destroyed. 



The Rose Seetle [Cetonia aurat(Cj. — This 

 ought properly to have been noticed with the May 

 Bug or Cockchafer. It is very destructive in some 

 localities — ^not as a grub, but a perfect beetle. The 

 wings and body are a beautiful mixture of green 

 and gold, and it is about three-quarters of an inch 

 in length, and, unlike many of our foes, it is bold 

 and brave, coming in the fierce light of the warmest 

 sunshine with a, frankness and force as if it were 

 monarch of every Eose it surveys. After flying 

 around a few times with great force and fury, it 

 plunges all of a sudden into the heart of a, half- 

 opened bud or choice bloom, and proceeds forthwith 

 to rend, bruise, scatter, and devour the petals and 

 any stamens and pistils there may be found on the 

 flower. 



The Carpenter Bee {Megachile centuncularis) 

 —It may almost seem absurd to suppose that a veri- 

 table bee, endowed with all its gregarious faculties, 

 and the venomous sting of a bee, should bite and 

 devour Eose-leaves, and even small twigs. The bee 

 is about half an inch long, of a brown-black colour, 

 the thorax covered with wool. It builds its nest 

 on the ground, and this particular species of the Car- 

 penter Bees chooses to build and enlarge it with the 

 leaves of the Eose. Others elect other living flowers 



