128 JOUENAI, OF ENTOMOLOGY AND ZOOLOGY 



7000 to 8000 feet, but I have never found T. telarius Linn, above 

 an elevation of about 1500 feet, yet I see no reason why it should 

 not be found above this elevation. 



Under out-of-door conditions we do not have temperatures so 

 high as to check this species. It is claimed that in the hottest 

 part of the summer in southern California the spider mite 

 does not thrive as well as where the temperature is not so great. 



This species does not thrive as well in a wet climate as in a 

 dry one. Yet neither an excessively wet nor an excessively dry 

 climate will prohibit its development. 



The presence or absence of favorite host plants has much to 

 do with the distribution of the spider mite. The absence of an 

 acceptable host precludes its existence in any region. 



Lastly, this pest being one especially fond of greenhouse 

 plants, may be found wherever plants are grown under glass 

 with the aid of artificial heat. Doubtless it is found in many 

 places under these artificial greenhouse conditions where it 

 could not persist out of doors. 



