THE BED SPIDER ON COTTOlSr. 



39 



Fig. 10. — Triphleps insMiosus, an important enemy of the red 

 spider: Adult. Muchi enlarged. (McGregor). 



(1914); and Parker (1913) states tliat a closely allied species, T.tris- 



ticolor, WSLS tlie most numerous red-spider enemy in the hop fields, but 



that no controlling effect could be detected. 

 This predator, coming 



upon a red spider like a 



flash, thrusts its sharp 



proboscis through the 



mite's back and siphons 



out the body contents. 



In the case of one bug, 



the first mite was drained 



in about five minutes, 



but each succeeding meal 



was of shorter dui'ation, 



so that the average time 



rec[uired for each meal 



was found to be about 



three minutes. The ac- 

 tions of the nymph (fig. 



11) are similar. Both 



adults and nymphs feed 



upon the mites in all stages from egg to adult, but the Triphleps adult 



will not ordinarily consume mite eggs unless other food is scarce. 



The operation of draining an egg 

 requires about two minutes. 



These bugs pass the winter 

 in the adult stage and usually 

 become active some time in 

 April, although they have been 

 seen as early as the middle of 

 March. Triphleps becomes ex- 

 tremely abundant by the first 

 of July, and assists greatly in 

 the reduction of the red spiders. 

 Although it seeks hibernation 

 toward the end of October, in- 

 dividuals are commonly seen 

 some years as late as the middle 

 of this month. 



By referring to Tables VIII 

 and IX it will be seen that 8 in- 

 dividuals collected as various 



iijstur.s of the nymph drained 1 ,856 red spiders in 57 feeding days. 



The average daily consumption of the nymph was 33.16 mites, that 



of the adult was 28.88, and the daily average for all individuals was 



Fir;. II. 



• Triphleps ifuidifjsut: X ymph. 

 larged. (McGregor.) 



Greully en- 



