July 1942 ET-197 
 
 United States Department of Agriculture 
 Bureau of Entomology and Plant Quarantine 
 
 A RECOVERY CAGE TO DETERMINE THE NUMBERS OF FLEA BEETLES EMERGING 
 FROM SOIL SURROUNDING HOST PLANTS 
 
 By J . U. Gilmore and Cleraence Levin, 
 Division of Truck Crop and Garden Insect Investigations 
 
 The apparatus described herein was developed at the Oxford, 
 N. C, laboratory and has been used rather extensively during 
 the last several seasons for obtaining estimates of the numbers of 
 adult tobacco flea beetles (Epitrix parvula (F.)) emerging from the N 
 soil, particularly in tobacco plant beds. With slight modifica- 
 tions in shape, size, and covering it can be used in experiments 
 with many different insect pests where an efficient cage suitable 
 for retaining such insects is required. 
 
 The finished cage is cylindrical and will cover a space 
 equal to 1 square foot on the soil surface. The frame is con- 
 structed of -j-inch rods of black malleable iron and measures 21 
 inches in height and 13-g- inches in diameter (fig. 1, A). The two 
 circles are made from single lengths of the rods, 42.4 inches long, 
 which are shaped in a pipe former and the ends welded together. 
 The three supporting rods are spaced at equal distances about the 
 circles. The upper circle is welded to the ends of the three up- 
 right rods, which are then attached to the outer side of the lower 
 circle. After the eight welds are made the frame is painted to 
 retard oxidation of the metal . 
 
 Cloth, consisting of 32 by 28 strands per inch, is sewed to 
 form a cylinder 36 inches long, v/hich is slipped over the frame. 
 This cloth envelope is sewed to the lower circle and attached with 
 thread at six places on the upper circle. To preserve the cloth 
 near the ground, a strip 3 inches wide around the base of the cage 
 is sprayed with paint. 
 
 The cage is placed in position for operation by forcing the 
 projecting rods into the ground and banking 1 or 2 inches of soil 
 around the base to make it insect-tight. The open cloth top is 
 closed with a string slip knot, and the other end of the string is 
 attached to a stake, as shown j.n figure 1, B. 
 
- 2 - 
 
 7/hile these cages are not often required to withstand rough 
 usage, they are substantial enough to be operated for many seasons. 
 Some of them have been used during four seasons to date and, with 
 annual painting, can be used indefinitely (fig. 2). The cloth 
 envelopes, the bases of which by necessity must come in contact 
 with the soil, last from a month to 6 weeks, even under conditions 
 of excessively heavy precipitation. This is sufficient time for 
 the development and emergence of a single brood of the tobacco flea 
 beetle. During a 30-day period a total of 796 beetles were retained 
 and recovered in one of these cages situated in a tobacco plant bed. 
 Actual recovery is effected by opening the top of the cloth cylinder 
 and removing the beetles in any manner desired. 
 
 i 
 
Figure 2, — ^A series of recovery cages in operation in a tobacco 
 plant bed adjacent to a tobacco field. 
 
 Figure 1. — ^Recovery cage. A, Recovery cage frame, uncovered. 
 B, This recovery cage, covered, staked, and mounded, is 
 ready for operation. 
 
UNIVERSITY OF FLORIDA 
 
 3 1262 09240 9803 
 
 UNITED STATES DEPARTMENT OF AGRICULTURE 
 OFFICE OF THE SECRETARY 
 WASHINGTON, D. C. 
 
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