27 



water and not on nocturanl conditions. The author wishes to acknowledge 

 the possibility that the snail may be dependent upon free water which 

 develops on the leaf surface. Further studies examining this environ- 

 mental factor are needed. 



Section 3. Effect of Snail Movement on Fruit Microbiota 

 Using Scanning Electron Microscopy 



Introduction 



No information was available on D^. dormani effect upon the micro- 

 biota of citrus. Therefore, this study was undertaken to characterize 

 the microstrata of the gruit surface and the effect of D^. dormani on it. 

 Materials and Methods 



Scanning electron microscope work was done at the Orlando location 

 of the U.S.D.A., Horticultural Research Laboratory, Orlando, Florida. 

 All D. dormani used were collected in Orange Lake, Florida, from the 

 Parson Brown variety of Citrus sinensis (L.) Osbeck. Green fruit, 6.5 

 to 7.0 cm in diameter, were collected in Lake Alfred, Florida, and were 

 selected on the basis of high citrus rust mite spermatophore counts. 



A glass aquarium (1' x 2' x 1 1/2') used to house the snail was 

 maintained at relative humidity (R.H.) of 90% + 2% by filling the 

 bottom with one inch of water. D. dormani were placed on five oranges 

 suspended by cotton strings attached to the top of the aquarium. The 

 string was tied to paper clips partially opened and inserted into the 

 fruit. 



Snail trails were recognized easily by a wet silvery sheen left on 

 the fruit surface. Each trail where feeding had occurred was marked 

 with a felt tip marker for identification. Twelve 4 x 4 x .05 mm samples 

 were carefully removed with a single edge razor blade from the surface 

 of the fruit in each of the following three areas: control areas (not 



