March, i9^o.] DiCKERSON & VVeISS : EVEXING PklMKOSE INSECTS. 33 



Before taking up the accounts of the insects associated with the 

 evening primroses, it will not be out of place to call attention to a 

 paper by Alice Adelaide Knox on " The Relation of Injury to Fascia- 

 tion in the Evening Primroses," which appeared in The Plant World 

 (Vol. 10, No. 7, July, 1907). Parts of this paper are quoted below. 



"Examination of species of CEnothera by cutting or splitting 

 the axes, reveals within many of them comparatively large numbers 

 of the larvae of a small moth named Moniplia, which suljsist on the 

 pith toward the end of summer, and winter in the hollow stem. 

 Some of the larvK develop in the ovary and emerge in the winged 

 state from the ripened capsule. Still others hatch in the leafy tip 

 of the flowering stalk or in the rosette, and in the latter bind together 

 the leaves to make a protective covering and feed in its heart during 

 the cold months. In each case the eggs are laid in the growing 

 region, so that the initial meristem is subject to injury from the ovi- 

 positor. In the last instance large mutilations may be caused by the 

 devastations of the feeding, and such ravages account for the fre- 

 quent abortion of the main axis among the fasciatcd plants. On tlie 

 other hand many plants remain unaffected, for the new leaves fur- 

 nish sufficient food, the larva does not penetrate the center of the 

 axis, and never reaches the meristem. In still a third case the 

 meristem may be barely touched or irritated, and the injury may be 

 a one in its effects similar to those caused by the ovipositor. Where 

 the wound is inflicted by the mouth parts of the larva it is ordinarily 

 more easily detected than when made by the ovipositor of the imago, 

 for it frequently interferes with procambial development in such a 

 way that the bundle ring is symmetrical, or there is a conspicuous 

 callus formation, or other signs are evident, by which its course may 

 be traced and its origin ascertained. When the tissues are pierced 

 by the ovipositor the injury is so small that it is impossible to find it 

 after any considerable amount of growth has occurred. A compara- 

 tively deep incision measures 1.25 mm. in longitudinal section; it 

 disappears almost immediately upon the consequent enlargement of 

 the surrounding cells, and it is useless to look for traces of it at 

 advanced stages of development. Fasciated tips so young that their 

 flattened character can only be determined microscopically show- 

 wounds in the meristem at the apices, but as the banding of the stem 

 becomes conspicuous, aJl traces of the disturbance are gradually 



