l8o ENTOMOLOGISK TIDSKRIFT I913. 



Samma iakttagelse gjorde Statnton (1885, s. 286). 



Den förste, som försökte att förklara fenomenet, var 

 Wood. Han skrifvcr (1894, s. 153): »It is a most curious 

 and striking phenomenon. The leaf shall have put on its 

 red or yellow autumnal tint, it shall even have dropped from 

 the tree, have died and turned brown, but the area in which 

 the larva is feeding will remain alive and green, not merely 

 for days but for weeks, provided it be not exposed to ex- 

 cessive dryness». Han fortsätter därefter: »Looking at one 

 of these green patches with its margins fading gradually into 

 the surrounding brown area, it its almost impossible to escape 

 the conviction that it is produced by some substances that 

 we may call a poison, or better still looking at its effects, a 

 preservative, which, taken up by the sap, is carried to the 

 cells, and being appropriated in its progress gets more di- 

 luted and attenuated the further it travels. What this sub- 

 stance may be, whether a secretion specially provided for 

 the purpose, and poured out from the mouth of the larva, 

 or possibly some excretary substance present in the frass, I 

 am quite unable to say. At any rate the whole virtue of the 

 operation seems to be exercised whilst the larva is still 

 young, and, once accomplished, the life or death of the 

 creature is of little or no consequence.» 



Detta förhällande, att, äfven om larverna dö på ett ti- 

 digt utvecklingsstadium, den del af bladet, där de började 

 anlägga sina minor, likväl bibehåller sin gröna färg, förklarar 

 Wood på så sätt, »that some substance is produced which, 

 being absorbed by the vascular bundles among which the 

 larva is burrowing, gets distributed to the parts of the leaf 

 they supply, where it is taken up and appropiated by the 

 cells. >^ 



Denna företeelse, att höstminorna i bladen bibehålla sin 

 gröna färg, efter det att den öfriga delen af dem vissnat, 

 kan man äfven iakttaga pä Li///oco//i-f/s-m\novna, med den 

 skillnad, att hos dessa den gröna, skarpt begrimsade fläcken 

 pä bladet upptager alldeles samma område som minan, under 

 det att hos A^^/Z/r/zA?- minan fläcken gradvis, nästan omärkligt 

 öfvergär i det öfriga bladets färg. 



Wood har iakttagit, att A^r/Z/V/z^r-larven visserligen ej 



