54 THE BUOWX-TAIL MOTU. 



})illar8 arc destroyed early in the fall by a fungus or mold 

 which develops in the Avebs. The caterpillar destruction 

 from this cause is most noticeable during a tall that is espe- 

 cialh- damp and rainy ; we have never noticed it taking 

 place ill a dry fall. It is most common in those webs 

 which arc si)un on trees Avith large leaves, such as the maple 

 or horse-chestnut. These Avebs are of necessity more open 

 than those spun on trees Avith smaller leaves, such as the 

 pear or avUIoav. The rain penetrates these larger and more 

 open Avebs, and dampens the masses of excrement which are 

 found in many of the chambers of the Aveb. It is evident 

 that Avhen these Avebs become thoroughly dampened inside, 

 the molding and death of the caterpillars usually occur. 



Elect ric Ln/Jifs. 



Although electric lamps can hardly be classed among the 

 *' natural'' enemies of the moth, they exercise none the less 

 a very important influence in destroying the swarming moths 

 during the flying season. We have pointed out in another 

 place how these lamps, by attracting the moths, materiaWy 

 increase their distribution. It is well to shoAV, therefore, 

 the good done by the lamps in destroying the swarming 

 insects. The moths come out in lari>e numbers soon after 

 the lights are turned on, and from ten o'clock to midnight 

 the swarming is at its height. The moths encircle the lamps 

 at times in such numbers as to somcAvhat obscure the light. 

 The bodies of those killed b>' the electric current drop con- 

 tinually, and ])y morning the ground under the lamps in the 

 Avorst-infested regions is liberally sprinkled Avith bodies of 

 dead moths. Counts of dead moths under five arc lamps 

 Avei-e made at four o'clock in the morning on July 1«), hSDT, 

 with the following results: laniii NO. 1, 2?)C) males, 71 

 females ; hiiiii) Xo. 2, 2i» males, 1 1 females ; lamp No. 8, 

 7 males, 4 females; lamp No. 4, 'A males, 4 females: lamp 

 No. f), 22 males, 2 females. 



I^aiiip cleaners report that they often find a quart or more 

 of dead moths in the lamps earh' in the morning. ^Nlr. Kirk- 

 land spent several nights in 1897-98 Avatching the SAA^arming 

 of the moths, and found that toAvards morning many of the 



