Trombidiformes 153 



With the development of the early spring leaves, the deutogynes lay eggs 

 which hatch into nymphs producing primary mites on the leaves. These 

 primaries soon begin active reproduction of additional primary mites. Be- 

 ginning about the last of April or early May, new deutogynes appear 

 among the primary types and when full fed, these deutogynes travel down 

 the stems 6 inches or more. There they crawl into crevices or other shelters 

 on the previous season's wood. Thus deutogynes are leaving the leaves 

 through May and until leaf drop in the middle of July. The primary mites 

 are confined to the leaves and green tissue and perish with it, although 

 reproduction has largely ceased by early July. The mites prefer the under- 

 side of the leaves, but usually there is such a high population that both 

 surfaces are inhabited and considerable leaf "rusting" results. Once the 

 deutogynes attain a suitable crevice they become dormant and partially 

 dry out in late summer. However, winter rains and frost reverse this proc- 

 ess and recondition the deutogynes for activity the following spring. There 

 is a high mortality among the deutogynes, principally because of crevice 

 limitation. 



While the spring progeny of the buckeye Oxypleurites deutogynes were 

 not critically examined, it was noted that the first series of primary types 

 contained egg-laying females, indicating either predormancy fertilization 

 of the deutogynes or a deuterotokous reproductive capacity. 



Putman, 1939 (Seventh Ann. Rpt. Ent. Soc. Ont. p. 33), working with 

 Phyllocoptes fockeui in Canada, has described what is clearly discerned to 

 be a functional deutogyne, and states that both males and females hatch 

 from eggs laid by overwintering females. He considers that these overwin- 

 tering females (deutogynes) may have been fertilized before hibernation, 

 since he showed that ordinary unfertilized females (protogyne) produce 

 only males. Putman further noted that the production of "hibernating 

 forms" seemed correlated with foliage hardening, a speculation consistent 

 in the main with observations on the buckeye mite. 



The fig mite, Aceria ficus (Cotte), which illustrates a simple life 

 cycle, does not directly cause serious injury to the fig in California, as 

 do some eriophyids to their hosts. The mites live in the bud scales, on 

 the leaf surfaces, or inside the greerj figs. If the population is high 

 enough individual bud scales are scarred and some immature leaves 

 killed within the bud. The scarred or rusted condition is seldom no- 

 ticed on the mature leaves. However, this rusty condition is quite no- 

 ticeable within the fig where the usual damage is to the eye scales only. 

 With a large population the scarring may penetrate the interior of the 

 fig. It is thought that the smuts and molds of the figs {Aspergillus, 

 Hormodendrum, Caldosporium, Rhizopus) obtain an early foothold 

 on the necrotic areas caused by the feeding of the mites within the fig. 



