February, '15] 



DAVIS: STUDYING UNDERGROUND INSECTS 



139 



Since this paper was ^Titten Mr. A. A. Girault has published an 

 article on methods of rearing Scarabseid larvse (Jour. Econ. Ent., 

 Vol. 7, Dec. 1914. pp. 445-447). The author concludes that the under- 

 ground Tower cages, which in this case are presumably underground 

 cyhnder cages made of wire gauze, are the most satisfactory, wooden 

 boxes next and the flower pots third choice. Other circumstances not 

 referred to in the table must have influenced these conclusions since 

 they are not satisfactorily corroborated therein. Girault does not 

 indicate the size of pots or Tower cages used and this might have a 

 decided influence on the percentage of maturities, nor does he indicate 

 the number of grubs per cage except in the case of a few examples and 

 it is evident that up to a certain limit, the fewer the grubs the greater 

 the percentage of maturities, other factors being equal. Furthermore, 

 only larvse within five months of pupation were used and in the case 

 of the flower pots all were kept indoors (apparently not buried) , hence 

 it is impossible to make a satisfactory comparison between the results 

 secured by Girault and those of the writer. In the case of half-grown 

 grubs it is quite certain from our own results that the small individual 

 tin boxes will prove as satisfactory, if not more so, than pots or other 

 cages. Girault makes an excellent point and one which we corrobo- 

 rate when he says, ''It would seem that the kind of cage mattered very 

 little, providing they received good attention." 



Explanation of Plates 3-5 



Plate 3, fig. 1. Large underground breeding cage of 20-mesh Pearl wire cloth. 

 Fig. 2. 15-inch pots with wire screen dish cover tops. 



Fig. 3. Large underground breeding cage of 20-mesh Pearl wire cloth covered with 

 6-mesh wire screen. 



Fig. 4. 15-inch flower pot cage with cylinder-shaped tops. 

 Plate 4, fig. 5. 5 ? 8 ft. underground breeding cage. 

 Fig. 6. Flower pot saucer egg cage. 

 Fig. 7. Tin box egg cage. 



Plate 5, fig. 8. Compost heap in which certain cages are buried during the winter. 

 Fig. 9. Row of flower pot underground cages covered with strawy manure. 

 Figs. 10 and 11. Tray containing individual tin box cages. 



Fig. 12. Individual tin boxes showing white grub in prepupal stage and cell 

 constructed by it (natural size). 



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