A(il»ICUI/ri'KAL AFPHOFRIATION HU.U ^^^i- 297 



<*urry on cooperative work in Wisconsin witli the VVisronsin Kxpori- 

 incnt Station, principally alon^ tlir lin(> of a<lai)tit)^ rorncdios for um- 

 in <Mni)<'rv fields. T he lar«;<'r pari «»f the work would ]u' carried on 

 in Wisconsin, although the surronndni^ .States Indiana. Illinois. 

 Michif^an. and Nfiiuiesota are platinin^ to ^ive idl the cooperative 

 assistance possible. 



Doctor IlowAKi). How alxtiit the California work on this same 

 proi)osition ( 



Mv. CiKAK. The California work will he continued, but the situation 

 is entirely different in the W«'sl. Peas are plant<Ml in rows and can 

 he treate<l with sprays. Some additional l)iolo«;ical work will be 

 <hnie in an attempt to <liscover the source of infestation in the sjjnn^. 

 -Vpparentlv* in tlie Middle West the aphis must migrate from wild 

 fo«)d plants to the peas. In California they are ap|)arently f)resent 

 on the pea plants just as soon as they (onie out of tin* <;roun«l and 

 breed up slowly, an<l the work in California will be larj^ely an attempt 

 to determine if there is not some hope of stopping; the early infestation 

 ami thus let the peas j;et enou«;h of a start so a crop may ))e jjrown 

 with few or no insecticide treatments. 



COST uy TKKATMENT PKK .\(RK. 



Mr. Andkk.son. What is the cost of treatincr an acre of peas with 

 the nicotine dust '. 



Mr. (iHAF. Kowed or broadcasted j)eas ? 



Mr. Andkrsox. No; broadcast. How do you do it ? 



Mr. (iRAF. That is a diflicult cpiestion. It is just about impossible 

 to spray these fields with our present ecpiipment. In the ease of 

 dustiii};. one can use a <luster mountecl on an automobile truck and 

 equipped with a canvas trailer to hold the dust in the plants long 

 enougli to kill the aphis. This is the reason we are working on dusts 

 more than other remedies. 



I should say that spraying the broadcasted j)eas would cost about 

 $4 to $6 an acre and would hardly be effective on account of being 

 a downward spray instead of underspray. 



Mr. Andkrsox. Will this dust get down underneath so as to kill 

 the bugs underneath the leaves i 



Mr. (traf. Yes, sir. We have had very good results so far as the 

 killing goes. The (mly sticking point has been the cost thus far. 

 This canvas trailer is fastened to the rear of the truck, and it also 

 serves t<» drag manv of the aphids out of the i)lants and drop them 

 down on the ground, where they are readily killed by the dust. 



The strength of the wind at the time of dusting is an important 

 consideration. If the wind is too strong, it sweeps all of the (fust out 

 of the plants before it has time to kill the insects. 



POT.\TO WEEVIL IN .MISSISSIPri . 



The other item covei"s tlu' new potato wee\il in Mississippi. This 

 iiiscct was discovered last spring. 



Mr. BrcHAXA.N. The Irish potato^ 



Mr. (JifAF. Yes, sir. It only exists, so far tvs we know now. in 

 about lOO square miles in south Mississippi. One of the growers 

 fi»und that his tomato and potato plants were being entirely de- 

 stroyed. He could not find the insects causing this injury, since they 

 feed only at nijrht and hide under clods or trash in t^e daytime. 



