THE STRAWBERRY ROOT LOUSE. 



ApJiis forbcsi Weed. 



The first and only comj^laint of this insect, 

 which may be a serious obstacle in the way of 

 strawberry raisers, came from Stillwater in July, 

 1908. A visit to that locality disclosed its pres- 

 ence on about nine rows containing 1,000 plants 

 on the place of Superintendent Larson. Six of 

 these rows were Warfields, two Senator Dun- 

 laps, and one Lovett. The Warfields were orig- 

 inall}' purchased in 1007 from a grower in Michi- 

 gan, and these vines after planting were noticed 

 Fig. 72. strawberry Root by Mr. Larson to be unhealthv in appearance, 



Louse. Oi-iguial. -^ . i i > 



as were those in the older bed (mostly Senator 

 Dunlap) immediately around the Warfields. The nine rows infested 

 with this louse were set out in the spring of 1908, and for the most 

 ])art looked poorly, with foliage not well developed at the time of our 

 visit, July 28th. 



Mr. Larson reported that two years previous a grower four miles 

 froiu him was troubled in the same way, but that his neighbor 

 thought the injury was caused by ants. It is possible and probable that 

 the Strawljcrry Root Louse was the guilty party, and that the ants 

 (also seen in abundance about the aiTected plants at Mr. Larson's) 

 were attendant upon the lice, for, curiously enough, ants of the genus 

 Lasius care for these lice when young, carrying them from the leaves 

 to the roots. According to Prof. Sanderson "the ants are solely re- 

 sponsible for carrying the lice to the roots, as up to the time of the 

 ants' appearance no lice are to be found upon the roots. * * * 

 When one plant becomes overcrowded the aphids are carried to a 

 neighboring plant, and in this way the ants are almost entirely respon- 

 sible for the spread of the aphids th.roughout a bed, as well as for 

 carrying them to the roots of the plants." 



Eggs are laid in the fall upon the stems and leaves and hatch early 

 in the spring. There are apparently several broods, and they may 

 spread, not only from plant to plant through the agency of ants, but 

 also from one field to another at some distance away by means of 



