42 



Polysciences , Inc.) in the refrigerator overnight or for 

 several days prior to postf ixation. Specimens were washed 

 in buffer, postf ixed in buffered 1% osmium tetroxide for 

 2 hours at room temperature, washed in deionized water, 

 and en bloc stained in 0.5% aqueous uranyl acetate overnight. 

 Specimens were dehydrated with acidified 2, 2-dimethoxypropane 

 (Lin et al. , 1977) and infiltrated and embedded in a Spurr- 

 Quetol 651 resin (Ringo et al., 1979). 



Blocks were sectioned with a LKB Huxley ultramicrotome. 

 For light microscopy, 2-4 um sections were cut on dry glass 

 knives, spread in a drop of 10% acetone, mounted in immersion 

 oil, arid studied by phase-contrast microscopy. Thinner 

 sections, 0.5-1.0 um, were stained with 1% aqueous toluidine 

 blue in 1% aqueous borax, rinsed in deionized water, mounted 

 in immersion oil, and examined by either bright-field or 

 phase-contrast microscopy. For transmission electron micros- 

 copy, gold sections were poststained with 2% aqueous uranyl 

 acetate followed by lead citrate (Reynolds, 1963). Grids 

 were examined and photographed at an accelerating voltage 

 of 75 kV in a Hitachi H-600 electron microscope. 



Results 

 Portraits of healthy and diseased male, female, and 

 worker pupae are presented in Figs 6-8. The clearing in 

 the dorsal thorax of the sexual pupae does not occur in 

 worker pupae, and occasionally is reduced or absent in 



