1140 Marvels of the Universe 
It exhibits no tendency to produce 
“moss,”’ and is usually quite smooth. 
It is caused by the presence of the larve 
of Rhodites eglanteriz. 
Another spherical gall occurs on the 
leaflets of the Dog Rose and Sweet 
Briar. It is very distinctive in having 
spiny outgrowths of variable size. It 
results from the attack of Rhodites 
rosarum. It is generally greenish, but is 
sometimes beautifully tinted with pink 
or red. It occurs chiefly on the midrib, 
is usually gregarious, and is often de- 
formed through the presence of parasites. 
The three galls described above may 
sometimes be found on one bush. That 
three closely-allied insects attacking the 
Ses ra nae am Ga same plant, and the same part of that 
PEA-GALLS OF ROSE. plant, cause three dissimilar galls to 
by the puncurts os tealer of Gallons Gifetel ioe iiesmas  atise, eachlot which|isconstant inform, 
causes the Bedeguar. (Natural size.) whatever may be the species of rose 
visited, clearly indicates that the larva of each causer has its own particular irritant, probably a 
fluid excretion, which causes the cells to deviate from their normal mode of growth. It must be 
remembered that the insect does not make the gall; the term “ gall-maker,” though frequently 
applied to it, is a most unfortunate and, 
indeed, misleading one. 
Brief allusion must be made to some 
rose-galls not illustrated in this work. 
The Burnet-leaved Rose is often 
attacked by Rhodites spinosissime. This 
wasp lays its eggs in all parts of the 
plant, excepting the root. A single gall 
is an ovoid swelling, about the size of a 
small pea, soft and greenish at first, 
becoming very hard and bright red at 
maturity. These galls are frequently 
coalescent, forming large masses. 
The Leaf-rolling Sawfly, Blennocampa 
pusilla, oviposits in the leaves of the 
Dog Rose. The margins of the leaf 
roll inwards, ultimately providing two 
pouches in which the larve live. Culti- 
vated roses are frequently attacked by 
this insect, which is becoming a serious 
pest in rose-gardens. 
A minute fly, Perrisia rosarum, 
Photo by) (4. H. Bastin. “9 5 5 ig A 
SPIKED PEA-GALL. attacks various wild roses, Oviposting in 
The galls here shown in different stages of growth are very notice- the leaflets, the edges of which fold up- 
able on account of their remarkable form, Note their similarity to the 
wards until their margins meet. The 
Spiders’ egg-cocoons shown on page 1116. (Natural size.) 
