212 INJUKIOUS INSECTS 



BLACKBERRY BORERS. 



Several species of Borers infest the Blackberry: the 

 most common one is the larva of a small, slender, red- 

 necked beetle (Oberea perspicillata, Hald.), fig. 131. The 

 small, legless grubs bore the pith of the canes, causing 

 them to die prematurely, or so weakening them that they 

 are broken down with the wind. As there are some four- 

 teen or fifteen species of the Oberea now known, it may 

 be that more than one species breed in the Blackberry. 

 Thus far, however, I am not aware that they have been 

 very injurious, but it would be well to gather all infested 

 canes and burn them with their contents. 



The Blackberry is subject to the attacks of several spe- 

 cies of gall-insects. A fuzzy, prickly gall on the twigs 

 is produced by a four-winged fly (Diastrophus 

 cuscutceformis 0. S. ) Another species of the 

 same genus (Diastrophus nebulosus 0. S. ) pro- 

 duces a large pithy gall on canes, but both 

 of these gall-makers have very formidable 

 Fi. 131. parasitic enemies which keep them in check. 

 r -^ ere are a ^ so a ^ ew leaf -eating beetles, slugs 

 and caterpillars, that sometimes attack the 

 Blackberry, but they are seldom sufficiently numerous 

 or injurious to attract much attention. The larger 

 species are readily destroyed by hand-gathering, and the 

 smaller ones can usually be driven off by dusting the 

 plants with lime. 



The most formidable enemy however of both the Black- 

 berry and Easpberry is the Orange-rust, a minute fungus 

 ( Uredo ruborum). It is perhaps more abundant on the 

 Black-cap Easpberry (Rubus occidentalis) than on the 

 ordinary varieties of the Blackberry; still it is sufficiently 

 abundant and destructive to all to attract the attention 

 of horticulturists throughout the country. I do not 

 know of any remedy except to stamp out the disease by 



