318 



HOUSEHOLD INSECTS 



interfere seriously with the work of the peasants in gather- 

 ing their hay and grain crops. The harvest mites occur 

 also in Belgium, the Netherlands, and in parts of Germany, 

 where a severe infection of the mites is called "stachel- 

 beerkrankheit." Redbugs are abundant and troublesome 

 in Mexico, where they are called " Tlalsahuate " and in the 



West Indies where they 

 are often called " Bete 

 rouge." In the United 

 States they are also given 

 the name "chiggers." 



What redbugs are. 

 Redbugs are the young 

 or larval forms of differ- 

 ent species of true mites 

 that belong to the family 

 Trombidiidae. Probably 

 all of the redbugs found 

 in the United States be- 

 long to the one genus 

 Trombidium ; but there 

 is yet much uncertainty 

 regarding the actual 

 species of which the red- 

 bugs are the immature forms. It is likely that more than 

 one species is represented by the redbugs. The harvest 

 mite has been variously referred to the species Leptus autum- 

 nalis, Trombidium holosericeum (Fig. 109), and to the genus 

 Tetranychus, while the redbug commonest in this country 

 has been called Leptus irritans. The adults of the harvest 

 mites or redbugs are members of the class Arachnida, to 

 which the spiders belong, and have four pairs of legs. 



FIG. 109. Adult of harvest mite 

 (T. holosericeum). (X 20.) 



