74 



As it is evident that this species has a fondness for violets among 

 greenhouse plants, growers would do w^ell to keep a lookout for it in 

 times of its abundance on grasses and other outdoor plants. 



A general account of this insect, with illustrations of the larva, pupa, 

 and imago, was given on pages 78-85 of Bulletin No. 23 of the present 

 series; and, as a more detailed account of it will shortly ]>e published, 

 further mention may be omitted for the present. 



The remedies applicable to this species are the same as for the vari- 

 egated cutworm, at least as far as the occurrence of the fall avniy worm 

 in greenhouses is concerned. A consideration of remedies to be used 

 when this species is destructive in the field was given in the bulletin 

 cited. 



WHITE GRUBS. 



Several other common greenhouse pests besides those which have 

 already received special mention are often injurious to various plants 

 grown under glass, and are occasionally troul)lesome to violets by 

 attacking their roots. Among these are white grubs and wireworms. 

 Complaints of both forms of insects have i-ecently been made, but 

 unfortunately the species concerned in the injury have in no case been 

 identified, it being a difficult matter to rear these insects from mate- 

 rial which has gone through the mails, principally because they need 

 the best of care and attention, and require as well a considerable 

 period for their development, extending in some cases over a period of 

 three years. Nearly every florist is familiar with white grubs, but he 

 may not know that there are several hundred dilferent forms of these 

 creatures, each representing a different species of the f amil v Scarabseidse 

 or Lamellicorns. Fortunately only a small portion of the white grubs 

 are of prime importance economically, the remainder not attacking 

 living plants. The destructive forms subsist upon roots under soH 

 and about w^eeds and various cultivated plants, and most of these, 

 the typical white grubs, belong to the genus Lachnosterna. They 

 are brought into greenhouses in pots of earth, and occasionally in 

 manure, but as a rule the species which breed in decomposing matter, 

 such as manures, are much less destructive than the species of Lach- 

 nosterna. The different species can be distinguished from one another 

 onl}^ by careful stud}', and for practical purposes it will not l)e 

 necessar}'- to consider this subject in detail in the present })ulletin. 



The species of white grub shown in the accompanying illustration, 

 (fig. 20), may be taken as a type of this class of insects. The grub 

 itself, illustrated at {^, is of large size, of soft consistency, and white 

 or slightly yellowish in color. The body is wrinkled, covered sparsely 

 with fine hairs, and the head is ))rownish and armed witli strong 

 mandibles. 



This, as well as other grubs of the same class, habitually rest in the 

 curved posture illustrated. The parent beetle, shown at a, is a large 



