1776 



ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



dark head and tip and are nearly one 

 inch long. Thoy are almost the shape 

 of a letter "S" and have a very notice- 

 able point at the tail end. The pupae 

 vary from the color and shape of the 

 larvae to those of the adults. 



Life History 



The winter is passed within the canes 

 of the host plants in the larval and 

 pupal stages. The adults emerge in April, 

 and after mating the females begin to 

 insert their eggs into the tender tips of 

 the young shoots. The eggs hatch in a 

 short time into larvae, which work up 

 the shoots until the latter are killed, 

 when they turn and go down the middle 

 pith of the stems and transform in the 

 late fall and winter into pupae. There 

 is but one brood each year. 



FlR. ]. The Ra.spbeny Horn Tail. Hartiiila 

 cressoni. a. adult female: 1). adult male: 

 c, well-developed pupa : d, very voung pupa : 

 e and t. larvae. (EssIk, M. B. Cal. Hort. 

 Com.) 



Food Plants 



The native host of this insect is prob- 

 ably the wild rose. Raspberries suffer 

 most from the attacks. Cultivated roses, 

 blackberries and loganberries are also 

 food plants. 



Control 



Measures necfssary to remove or de- 

 stroy the eggs before the young larvae 



hatch should be inaugurated. As the 

 eggs are very tender and their locations 

 plain, great numbers may be quickly de- 

 stroyed by exerting a slight pressure 

 over them with the fingers, which in no 

 way injures the shoot. Cutting out in- 

 fested canes is also recommended. 



E. O. ES.SIG 



Oystkr-Shei.l Scale. See Apple Pests. 



Raspberry Cane Maggot 



Phorbia ruhivora Coq. 



A. L. LOVETT 



The new canes of the raspberry, logan- 

 berry, dewberry and blackberry are some- 

 times observed in the spring drooping in 

 a characteristic manner. If the affected 

 shoot is examined carefully, a bluish 

 ring will be observed at the base of the 

 wilted tip, and by cutting into the inte- 

 rior a small, whitish maggot is disclosed. 



The adult of this maggot is a fly, sim- 

 ilar in appearance to the house fly, 

 though somewhat smaller in size. These 

 flies appear in early April and are pres- 

 ent through May and June. The females 

 deposit eggs on the canes of their host. 

 The egg is usually placed in the groove 

 formed by the branching off of the leaf 

 axil from the growing stem. The egg 

 is white in color, elongated and of a fair 

 size. The maggot which hatches from 

 this egg crawls down the cane a short 

 distance and bores its way through the 

 surface of the stem and into the pith. 

 The maggot feeds down the cane for a 

 short distance, it then turns toward the 

 surface or bores through the woody tis- 

 sue to Just beneath the surface of the 

 bark. It now turns at right angles and 

 girdles the cane. This girdle constitutes 

 the bluish ring, from the effects of which 

 the tip wilts and dies. 



Remedial Measures 



Cut off the Infested canes well below 

 the girdle and destroy. 



Raspberry Root Borer or Blackberry 

 Crown Borer 



liembecia marginata Harr. 



A. L. LOVETT 



This insect has appeared in certain of 

 the bush-fruit districts of the Northwest, 



