TYDEUS MOLESTUS 



357 



These animals live on the stalks of cereals, and feed on vegetable and 

 animal juices ; they are therefore also found on corn-infesting insects. They 

 invade the barns and seek out the insects living in the dry grains of 

 corn, or wait for an opportunity of obtaining food. They have been 

 repeatedly observed on human beings, particularly labourers occupied in 

 handling grain ; their bite causes severe irritation, local elevation and 

 reddening of the epidermis, as well as fever. It cannot be positively 

 asserted that all cases of the occurrence of cereal mites on man relate to 

 Pediculoides ventricosus, as the descriptions are often insufficient. Geber 

 states that one form is Chrithoptes monunguiculosus , cr A cams hordei ; 

 Flemming mentions Tarsonemus uncinatus ; Roller Oribates sp., and Karpelles 

 Tarsonemus intectus. 1 



4. Fam. Eupodidce. 



Small tracheate mites, with moderately long or 

 short pedipalpi, composed of four segments, of 

 which the last segments bend ; chelicerae forceps- 

 shaped, with serrated edge ; legs with two claws, 

 more rarely with one, and terminating in a tuft 

 ornamented with fine hairs ; genital orifices on the 

 abdomen, surrounded by a circle of little hairs. 

 Most species live free, one lives parasitically on the 

 bodies of slugs. 



Tydeus molestus, Moniez, 1889. 



Male, 0*2 mm. in length, 0*125 in breadth. 

 Females, 0*225 mm - m length, 0-135 in 

 breadth ; gravid female 0*315 0*360 mm. in 

 length and 0*180 mm. in breadth. They 

 were observed by Moniez on an estate in FlG - 233. Tydeus moles 



_ . \ tus seen m profile, enlarged. 



Belgium, whither the creature had apparently (After Moniez.) 



been imported twenty-five years previously 



with Peruvian guano ; they appeared regularly in the summer 



and remained until the first frost set iii ; they were found on 



1 Lagreze-Fossot, A., and Montane, R. J. (Rec. agronom. soc. d. sc., agric. et belles 

 lettres du dep. de Tarn et Garonne, 1851, xxxii., No. 2) ; Robin, Ch., and Rouyer, " Erupt, 

 cutanee due d V A cans du ble " (C. R. soc. biol., 1867, iv., p. 178); Laboulbene, A., 

 and Megnin, P., " Mem. sur le Sphtzrogyna ventricosa " (Journ. de Vanat., 1885, xxi., 

 p. i) ; Geber, E., " Entzundl. Processe der Haut durch ein bis j'ctzt nicht bestimmte 

 Milbe veranlasst " (Wien. med. Presse, 1879, xx.) ; Roller, Jr (Pest. med. chir Presse, 

 1882, No. 36, and Biol. Centralbl.; 1885, iii., p. 127); Rarpelles, L., " Ein auf den 

 Mensch u. auf Getreide lebende Milbe" (Anz. d. K. K. Acad. d. Wiss., Wien., 1885, 

 xxii., p. 160, and Centralb. f. Bakt. u. Paras., 1887, i., p. 428); Flemming, J., " Ueber 

 eine geschlechtsreife Form der als Tarsonemus beschriebenen Thieve " (Zeitschr. /. d. 

 ges. Naturwiss., Halle, 1884, iii., p. 472) ; Rramer, " Zu Tarsonemus uncinatus Flem." 

 (ibid., p. 671) ; Moniez, R. " Sur I' habit, normal, dans Us tiges d. cereales, d'un paras, 

 dccid. de I'homme " (Rev. biol. duNord de la France, 1895, vii., p. 148 ; Traite de Paras., 

 Paris, 1896). 



