120 



llms far iinkiidw n. In xicw of lliis fact, dclaikHl observations of its 

 occin'rcncc arc worth rcporl iii<;' licrc. 



Two lines of investij^ation have been cari^fully followed uf) at my 

 ollice: the first, that of systematic ()bser\:ilion in the (ield as the 

 season closed and the plant lice disapixarcd ; and the second, (hat of 

 iiisectiiry e.\|)<'iMmenl,s cai'rie(| on lhroii,i:;hont the fall and wird.er. 'I'ho 

 most, coimeclcd ;md careliil series of held observations on the spc^cies 

 was made undei- my direction in ISSI by Ti-ofessor II. (iarmaii, then an 

 assisl.'int in my ollice. 



Imi;i,i) ( )itsi;uvA'i'i()Ns. 



Jnly iT), .l/)///.s' iiKiiilis was reported present on corn (the earliest 

 observation ol' the year) in all its smmner forms \\iiii;-e(| and windless, 

 adults, pupa', and undifferentiated youni;-. .Iul\' L'S, the uiniied louse 

 was found in a (ield of small corn beneath the I'ollcd tei'minal lea\-es of 

 two stalks out of many examined. ;\uf;'ust 2, it was found on sor<>;hum 

 and broom-corn in all slaves, (he adults beiiifi; bo(h winded and wiiifjless. 

 Au^'tist II, i( was common in all s(a,i;('s on (he leaxcs and (assets of corn. 

 .'\uj;ns( '1\ , i( was ;i,i;aiu obser\'ed on corn a( l'!irmi;ham, and on ( he 20th, 

 a( Carmi, winded aduUs were seen on corn leaxcs. Sep(embei' 5, ut 

 .Anna, in I mon coimly, in soudicrn Illinois, i( was common in (he (ield 

 on corn, the winded form beim;,' moderateb' abundant. September S, 

 vvinf;'l(>ss fem.ales ;ind youni;' were obser\('(| on corn at Ifban.a, often with 

 ;i siiii;le dead winded specimen anioiii; them probabb' the parent female 

 ol the colony. "September IS, soi;<i;lmm maluriui;' and beiiii;' cut. 

 i'lants pre\iously infested by lari^e colonii's as shown by cast skins now 

 ha\(' but few of the leaf-lice on tluMu.and t liese most 1\- winded." They 

 were most .abmid.aiit on t he ureener parts of st un(e(| plants. Tlu' winficd 

 lice were ll\iiii; freely in the cNcniiii!,' at (his time. ( >n corn they wiM'e 

 conuuonei' th.an on sorghum mostly winiiless specimens amoni;- the 

 husks of the greener e.ars, September l!>, an e\;miin;it ion of lari^'e num- 

 bers of (he wini;(Ml lice showed that they were ;dl \'i\ipai'ous females. 

 Most of the i^rowini;' yomit;' wci'e developini;- wini;-pads at this time. 

 Septembei' 22. S(ill \rv\ .abund;in( on corn, nearly ;dl winf^less \'ivi|)- 

 arous females ;ind ( heir youni;'. September 2."). .\( (iodfnw', Madison 

 county, Illinois, coimnon beneath (he coi'u husks ;dl w iiiii'Uvs.s fcMnalcs 

 and (heir youni;. ()ctober (>. Still present on corn, concentrating, 

 liowc\(>r, on the youni!,'ei- plants. Sonu^times fomiil on the ,i;r(MMier ears 

 of .st;dks which had be("ii cut and shocked. \\'in<;('d. windless, and vonng 

 all prt>sent. I.i\in<i youiiii; obtained from bodies of both winmHl and 

 windless adults, and even, in one c;is(>, from a pu|)a which had not yet 

 made its last moll, '['he winded ones lly \-ery r(>adily, and the wingless 

 are often seen w.andei'ing restlessly about the plants. .\nts in attendance* 

 {Lcuslus nlijir and (' renin filofjdsUr lincoldUi) make no attempt to carry 



