104 



Acarology 



ZERCONINA TRAGARDH, 1944 



This suborder is directly related to the Gamasides, and if it were not 

 for the position of the male genital opening in the center of the sternal 

 plate it would most certainly be included with the Gamasides. Only 

 one family is recognized in this group and thus its morphology can be 

 discussed at the familial level. 



Zerconidae Berlese, 1892 



Figure 76 



Diagnosis: Zerconids are small 

 mites with flat bodies that are 

 broadest in the posterior region 

 so that they have a somewhat tri- 

 angular shape. Their dorsal plate 

 may or may not be divided. Tar- 

 sus I lacks caruncles and fre- 

 quently has a reduced pretarsus, 

 while tarsi ii, in, and iv are all 

 provided with pretarsi, caruncles, 

 and claws. The ventroanal plate 

 is large and broad. The male 

 genital opening is located in the 

 middle of the sternal plate and is 

 closed by a double plate attached 

 at its anterior margin. The epigy- 

 nial plate has only one pair of 

 setae and is not fused to the endopodal plates. The metasternal plates 

 are so weakly sclerotized that their position can be detected only by 

 the presence of the metasternal setae. The sternal plate has the usual 

 three pairs of sternal setae. 



Genera: 



1. Zercon Koch, 1836 



Type. Zercon dimidatus Koch, 1841 



2. Parazercon Tragardh, 1931 



Type. Zercon scircikensis Willmann, 1939 

 (= Zercon ornatus Tragardh, 1910, 

 non Zercon ornatus Berlese, 1904) 



Figure 76 Prozercon kochi Willmann, 

 1943. Ventral view of female. (After 

 Willmann 1943) 



