APPLE INSECTS — BUDS AND FOLIAGE 111 



darker form occurs in which the yellow on the sides is entirely 

 obscured, and the whole caterpillar is of a dull dusky color, 

 but all gradations are found. 



Natural enemies. 



Few birds feed on these hairy caterpillars to any great extent. 

 Among predaceous insects their most important enemies are 

 the Mantis (Mantis Carolina) and the wheel-bug (Prionidus 

 cristatus), both abundant in the South. Of true parasites 

 the most important are Telenomus bifidus Riley, attacking 

 the eggs, Meteorus hyphantrice Riley, Apanteles hyphantrioe 

 Riley, and Limneria pallipes Prov., attacking the cater- 

 pillars. Good work is also done by an unnamed Tachinid-fly. 

 Unfortunately the efficiency of this series of parasites is greatly 

 lessened by the great number of secondary parasites, which 

 prey upon them. Under favorable conditions great numbers of 

 the caterpillars are killed by a fungous disease, Empusa grylli. 



Remedial measures. 



In the forest we must depend on its natural enemies to hold 

 this pest in check. On shade trees in cities spraying with an 

 arsenical poison and a thorough and timely removal of the 

 small webs while the caterpillars are still young will do much 

 to prevent serious damage. Especial attention should be given 

 to the destruction of the first generation, thereby lessening 

 the difficulty of controlling the second. In orchards where 

 arsenical spraying is regularly practiced most of the first brood 

 of caterpillars will be destroyed. The webs should be cut out 

 or burned out with a torch as soon as observed. This can be 

 done most easily while they are small and before any large 

 branches have been included in the nest. The webs should be 

 destroyed during the day while practically all the caterpillars 

 are within. 



References 



Riley, Rept. U. S. Com. Agr. 1886, pp. 518-539. 

 Lyman, 32d Rept. Ent. Soc. Ont., pp. 57-02. 1902. 



