218 REPORT UPON COTTON INSECTS. 



September 9, after sunset another gallon of yeast in four gallons of 

 water was applied to cotton covered with young larvae and eggs, but 

 with no result, so far as I could see. 



It will be seen that the first of these experiments was tried during a 

 rain, which endured for some time, so that the yeast may have been 

 washed from the leaves and from the caterpillars before having an op- 

 portunity to act; but if any of it adhered the damp weather following 

 was most favorable to its development into the parasitic form. The 

 second was tried when the sun was shining early in the morning, so that 

 it was exposed to sunlight for the greater part of one day, and could 

 not have been removed by rain till the following night. Like the former, 

 this was subjected to damp weather for a number of days. The third 

 lot was applied in the early part of a cloudy afternoon, and this was 

 subjected to rains the next night and for several days. The fourth lot 

 was applied after sunset, and there was no rain on it for three days. 

 Moreover, these quantities of yeast were so applied as to wet eggs, larvae, 

 and pupae of Aletia. Other applications were made on a small scale at 

 different times, but with similar results. 



From these experiments it appears that under the most varied circum- 

 stances, many of which are very favorable to the growth of fungi, yeast 

 in an active condition failed to produce any fungoid disease on either 

 the eggs, larvae, or pupae of Aletia. Furthermore, larvae contained in a 

 tin box were drenched with yeast, being kept thoroughly wet for over 

 twenty-four hours, after which a part of the liquid was drained out, and 

 the box remaining uncleaned, the larvae were kept and fed in it for a 

 week longer, at the end of which time they were still living and appar- 

 ently suffering from no disease. This leads me to believe that though 

 the Penicilliwm or Aspergillus developed from torulae sometimes attack 

 living animal tissues, they cannot be utilized for the destruction of the 

 cotton caterpillar. Yet, considering to what an extent some insects 

 suffer from fungoid diseases, it seems by no means improbable that some 

 practical and economical method of parasitizing noxious insects may 

 some day be discovered. 



Since the perfect form or moth of Aletia is known to feed upon 

 sugared substances and fruits, and since it is known to be attracted by 

 light to a certain extent, it has been thought possible to destroy the 

 moth by allowing it to feed on poisoned sweets, or by employing the 

 food or lights to attract it into traps of various sorts. 



As will be seen by referring to my report on the food of these moths, 

 they arc attracted in large numbers by ripe apples, peaches, and grapes, 

 beside one or two other less common fruits, but I signally failed to at- 

 tract them to my mixtures of molasses or sugar and various substances. 

 Though no experiments on a large scale were conducted, I feel confident 

 that poisoned dishes of ripened and slightly fermenting fruits which 

 have been bruised, may be advantageously employed for the destruc- 

 tion of these moths, by placing them about the cotton-fields wheu the 



