1912] Ewing and Webster — ilites Associated with the Oyster-Shell Scale 129 



Tli^at this mite is predaceous upon the scale insect or its eggs, 

 tliere is but little doubt. However, the case here is not so con- 

 clusive as it is with Hemisarcoptes malus, where we have time and 

 again observed the mites attacking the scale insects and their eggs. 

 The whole organization of the mouth-parts of this species {Tydeus 

 coccophagns) is suited for predaceous habits, and the other mem- 

 bers of the genus are known to be predaceous. These facts, to- 

 gether with the fact that we have found the mites under the scales 

 and associated with the eggs and adult insects, makes out a strong 

 case against them. However, these mites were frequently found 

 under empty scales in June and July, where they probably were 

 feeding upon the old decaying bits of eggs, etc., left from the past 

 winter and spring. But as soon as the scale insects reached ma- 

 turity, and began to deposit eggs, these mites were found in abund- 

 ance under these sound scales. A different species of this genus 

 is known to be an important enemy of scale insects in Florida. 

 All the species of the genus so far as known are predaceous. 



Bdella cardinalis Banks. 



Associated with the scales were frequently found very small 

 nj^nphs of the genus Bdella. Although none of these were reared 

 to maturity, their palpal characters, and the very common occur- 

 rence of Bdella cardinalis Banks under the bark of many kinds of 

 trees around Ames would indicate that these nymphs belonged to 

 that species. The Bdellidffi are predaceous in all their stages. 



Cyta brevipalpa Ewing. 



This very small, bright red species was found several times under 

 the scales. The species is known to have a wide distribution over 

 the Mississippi Valley, where it is found oh and under bark and 

 in moss. It is a predaceous form, and doubtless feeds upon the 

 eggs or the scale insects themselves, although it was not actually 

 observed to do so. One observation made July 14, 1911, records 

 the mite apparently feeding on old egg shells, etc., beneath an old 

 scale. 



Anystis agilis Banks. 



This very common and widely distributed species of Acarina 

 appears to be an enemy to the oyster-shell scale only in the larval 

 state. The adults are much too large to get under the edges of 



