REPORT OF PROF. R. W. JONES. [19] 



ment these black spots are arranged in two rows; the spots of the front row are 

 closer together on the back ; those of the rear row extend down farther on the side. 



Duration of the larva state from fifteen to twenty days. 



Chrysalis. — The larva bores into the ground to assume the pupa state. In my breed- 

 ing jars they went down two or three inches, the tube being oblique and open except 

 a very slight covering at the top and some of them lep-ving the entrance uncovered. 



I deem it unnecessary to give a description of the chrysalis, as you doubtless will 

 do so from specimens at hand which you will accompany with accurate drawings. 



The fact that the chrysalis of the ISoll Worm is under ground will prevent any one 

 from confounding it with the chrysalis of the Cotton Worm. 



On the Boll Worm chrysalis there is much more of a yellowish cast and more luster. 

 The time during which the pupae remained in ground ranged from eleven to sixteen 

 days. 



The whole time, therefore, elapsing between the laying of the egg and the appear- 

 ance of the moth from it is from thirty to forty days. 



Themotli. — The habits are very much like the moth of Aletia; it is larger, measur- 

 ing as much as If inches across the wings, and the largest being || inch long. It 

 begins to fly soon after sunset. I have watched it a great deal, but never saw it on 

 any flowers or leaves except those of cotton. It would often alight in the grass. It 

 feeds on the nectar of cotton. I put out lights in the cotton during part of the sum- 

 mer ; some were attracted and killed, but the success was not such as I expected. 



I have not seen the moth of Heliothis since the cold rainy weather about the last of 

 September. The thermometer early in the morning for several days was down to 40° 

 Fahrenheit. 



I have searched diligently without finding one. 



Weather. — Warm, damp weather favors the multij)li cation of Heliothis. In dry 

 weather, when it was very warm, I have seen the worm dead on the bolls without 

 having apparently suftered any violence ; the circumstances were such that I inferred 

 it died of heat and lack of moisture. 



The larvae of Heliothis are very quickly affected by cold rains. During the rains 

 previously referred to, occurring at intervals from Sei)tember 10 to 30, though the tem- 

 perature was by no means low enough for frost, I found larvse of Heliothis in the bolls 

 in a state of torpor, and in some instances they were dead. They are very sensitive 

 to cool rains. In many cases throughout the season I found bolls which had been 

 pierced more or less by Boll Worms, occupied by white footless grubs of a fly. The 

 fly deposits its egg in the decaying contents of the boll that has been abandoned by 

 the worm. These eggs hatch and the maggots feed on the putrefying matter. I have 

 seen some persons who snpposed that the maggots caused the rotting of the boll and 

 that the fly injured the boll in oviposition. This cannot be true. The boll rots be- 

 cause of the injury from the Boll Worm, and the decaying boll invites the fly. 



Natural enemies. — These (so far as I have been able to ascertain) are the same as 

 those mentioned in your Bulletin No. 3, which attack Aletia. 



I have observed the following enemies; / 



Birds: Swallows, Bee Martin, King Bird, Bluebird. 



Insects : Spiders, larvai of Lady Bird, Acanthocephala femorata, Wheel Bug, Soldier 

 Bug, Tiger Beetle. Bats catch many moths. 



Parasites : In the latter part of the season a great many larvae of Heliothis and 

 Aletia bore a white egg, which was found to be that of a Tachina. In some in- 

 stances the moths hatched out notwithstanding the egg of the parasite. In other 

 cases the chrysalis was destroyed by the grub ; the latter was generally the case. 



Sometimes as many as five eggs of Tachina would be found on one larva of Helio- 

 this or Aletia — more generally on Aletia than Heliothis. This Tachina must be an 

 exceedingly formidable enemy of both Aletia and Heliothis. 



Much has been said of the destruction of Heliothis by Ants. I have never seen 

 Ants eating them in any state until they had been killed or injured by some other 

 agent or had died, excejit when the worms Avere confined in jars ; even this was a very 

 rare occurrence. I think I observed it but twice, and both these instances were at 

 my residence ; no instance occurred in the laboratory where my work was done. 



Before proceeding to give an account of the vegetable preparations which I made 

 and my experiments with them, I will make a few observations on the 



COTTON A.RMY WORM. 



(Aletia xylina.) 



I will not refer to any facts coming under my notice that are contained in your 

 Bulletin No. 3. 



Alter a protracted season of cloudy days and frequent rains with a warm wind from 

 the South, we found Aletia, September 11, in a field near here ; the locality in the field 

 v^3is idetitically the same Afi that in which you found them October, 1879. From that 

 locality they gradually spread over the greater part of the field of 20 acres in cotton. 



