328 



The Dictionary of Gardening, 



Hose Sawflies — continued. 

 green above, with the Rides light grey, and ia sprinkled 

 with small shining white tubercles ; the legs are nearly 

 white, and the head varies from yellow to brown. The 

 larvEe, when full-fed, usually bore into the branches, and 

 there become pupa3 ; but they form their cocoons some- 

 times among dead leaves and other rubbish on the soil. 



E. mela na riim and E. riiforinctiis are nearly allied to 

 the last, with similar habits, but are not so numerous 

 as to call for a detailed description. 



Cladius pectinicornis is also rather common upon 

 Eoses in gardens. The Sawflies are a little over ^in. in 

 length, and are shining black, with scattered fine grey 

 hairs, and yellowish-white knees and feet, and faintly 

 smoky wings, paler near the tips, with the veins near 

 the base reddish. The larvas lie flat on the lower sur- 

 face of the leaflets, which they gnaw into holes between 

 the larger leaf-veins. They are flattened, and taper 

 from about the middle towards each end. On each 

 segment are three rows of warts, each of which bears a 

 long brown hair ; the head is small. The body is deep 

 green or yellowish-green. The cocoons are spun between 

 dead leaves. There are two broods in the year, the 

 autumn brood passing the winter as larvae in the 

 cocoons. 



Cladius Padi, a nearly allied insect, but only half as 

 long, is often plentiful, and is destructive to Eoses, as 

 well as to Pear, Plum, Hawthorn, Birch, and vai-ious 

 other trees and shrubs. Its larvae also eat holes in the 

 leaves. The cocoons are made in the soil. From two 

 to four broods have been recorded in the year. 



The genus Hylotoma, which has three-jointed antenna;, 

 and the larvaj of which have twelve or fourteen claspers, 

 or prologs, includes several species that live, as larva;, 

 on Eose-leaves, viz., H. eitodis, H. gracilicornis, H.pagana, 

 H. Bos(e, &c. Of these, the last-named species is the 

 most destructive, and we shall therefore describe it as a 

 type of the genus as regards habits of larva;. H. Rosw 

 is about tin. or |in. long, and is dull yellow, with black 

 head and antenna; and thorax ; all the legs are yellow, 

 save that their base.s and rings round the feet are 



Fig. 395. Larv.e of Rose-leaf Sawflv. 



black. The larva; (see Fig. 39.5) are bluish-green, with 

 yellow spots along each side of the middle line, and on 

 the sides are black spots, bearing bristles. The head is 

 black-brown. There are two broods, the insects appear- 

 ing in May and June, and again in Aiigust and 

 September. The females lay their eggs in slits in young 

 branches. The larva; hatch in a few days, and crawl 

 on to the leaflets, which they gnaw from the edge in- 

 wards. Fig. 395 shows two characteristic attitudes, that 

 on the left being assumed if they are disturbed. They 

 cast their skin about four times. When full-fed, they 

 creep underground, and there spin cocoons and become 

 pupa;. 



Lyda inanita is the only other Sawfly which we 

 shall mention specially as feeding on Eose-leaves. This 



Rose Sawflies — continued. 

 insect is black, except a broad, dirty, yellow band 

 lengthwise on the abdomen, yellow markings on head, 

 antennfe yellow at their base, and brick-red elsewhere, 

 and legs straw-yellow. The antennse are twenty-one- 

 jointed. The larva; are yellowish-green, with broken red 

 lines on the sides, and a black spot on each side of the 

 first body-ring. Each larva lives in a tubular sack, 

 formed of fragments of Rose-leaves arranged spirally. 

 When full-fed, it leaves its sack (then as much as 2in. 

 long), hanging to the back of a leaf, and burrows under- 

 ground, there to become a pupa, from which the Saw- 

 fly emerges next year. 



Remedies. Most kinds of Sawfly larva; can be shaken 

 off the bushes into vessels, or on to sheets, from which 

 they can be swept up, to be destroyed ; or the bushes 

 may be sprinkled with flowers of sulphur, or watered with 

 infusion of hellebore or of Paris green. Hand-picking 

 is effectual only if the bushes are few, but is the best 

 remedy for Lyda inanita and Blennocam2ia pusilJa, which 

 live concealed — not exposed, as do the others. It is 

 advisable also to capture the Sawflies, either by using 

 a sweeping-net, or shaking the insects off their favourite 

 perches into some vessel or receptacle. This should be 

 tried only in cloudy weather, as the insects are then 

 quite sluggish, but take to flight readily in sunny 

 weather. It has been found useful to grow flowering 

 plants of Parsley among the Eoso-bushes, as the insects 

 congregate on the flowers, and can easily be taken upon 

 them in the sweeping-net. The pupje may be destroyed 

 by removing and burning all loose, dead leaves, &c. ; and 

 by removing a few inches of surface-soil, in autumn, with 

 the cocoons. In this way, both those that become pupse 

 in debris, and those that do so in the soil, are destroyed. 



ROSI! SLUG. The popular name of the destructive 

 larva' of Bose Sawflies (which see), but more especially 

 employed for the slug-like larva of Eriocampa Rosw. 



ROSETTE MULLEIN. See Ramondia py- 

 renaica. 



ROSE WILLOW. See Saliz rubra Helix. 



ROSE, WIND. A common name ap- 

 plied to Paparer R]ia:as and Rwmeria hy- 

 brida. 



ROSEWOOD-TREE. A name applied 

 to several species of DaWergia, &c. 



ROSMARINUS (from ros, dew, and 

 mafitiHs, of the sea; referring to the habitat 

 of the plant). Okd. Labiatw. A monotypic 

 genus. The species is a densely-branched 

 and leafy, hardy shrub, employed in the 

 manufacture of Hungary Water. For culture, 

 &c.. see Rosemary. 



R, officinalis (officinal).* Common Rosemary ; Old 

 Man. rf. ill short, axillary, few-flowered racemes, 

 .ippriiximating, opposite, sub-sessile; calyx of a 

 purplish colour, ovoid - campanulate, bilabiate ; 

 corolla white or pale bliiisli-purple, the tube 

 shortly exserted, the limb Itilabiate. February. 

 I. sessile, linear, entire, with revolute margins, canescent be- 

 neath. Ii. 2ft. to 4ft. Mediterranean region, 1818. (S. F. G. 14.) 



ROSTELLARIA (of Nees). Included under Justicia. 



ROSTELLUM. A diminutive beak. A narrow ex- 

 tension of tlie upiier edge of the stigma of certain Orchids. 



ROSTRATE. Having a rostrum; terminating gradu- 

 ally in a long, straight, hard point ; e.g., the pod of a 

 Eadish. 



ROSTRUM. A beak-like extension. 



ROSULAR, ROSULATE. Collected in a rosette. 



ROTATE. Wheel-shaped ; circular and horizontally 

 spreading, very flat ; e.g., a gamopetalous corolla, with 

 a very short tube and a spreading limb. 



