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Psyche 
[Vol. 92 
Nymphal Coloration. Considerable inconsistency was noted in 
the regularity of the coloration exhibited by B. Carolina nymphs 
during the monthly collections (Pettry and Tarter, 1983). During 
fall and winter months, the majority of the nymphs exhibited a dark 
body coloration, with dark pigmentation on the legs and on the 
ventral surface of the head, thorax and abdomen. In spring and 
summer, as the nymphs grew and approached the emergence period, 
the dark pigmentation diminished among most of the nymphs. 
These monthly increases and decreases in percentages of light indi- 
viduals corresponded to the monthly increases and decreases in the 
growth pattern shown by nymphs, indicating that body coloration is 
associated with body size (r = 0.87). 
Traver (1931) noted considerable color variation in B. Carolina 
nymphs in the original description of the species. Also, Traver 
(1937) noted color variation in B. thomsenae (= Carolina) nymphs. 
This study confirms Traver’s original observations, and additionally 
indicates that two colormorphs exist in Panther Creek. 
Adult Stage 
Field Studies. Nymphs with developing wing pads were first 
observed in Panther Creek on April 23. Emergence in the field 
began between May 15 and 19 and continued through the end of 
August. 
Traver (1931) reported emergence of B. Carolina in April and 
May. Traver (1937) observed B. thomsenae (= Carolina) in May and 
June. The emergence period data reported for other Baetisca species 
are as follows: Pescador and Peters (1974), B. rogersi, April through 
early July; Morris et al. (1978), B. berneri, May and early June; 
Chaffee and Tarter (1979), B. bajkovi (= lacustris). May. 
Exuviae were collected during the emergence period to determine 
the yearly pattern of emergence. These data indicated a bimodal 
emergence pattern. The primary peak occurred in May when emer- 
gence began, with the other peak in August near the end of the 
emergence period. The data for early June may not correctly repres- 
ent the actual emergence pattern. Heavy rains were recorded during 
this time, 3.85 inches (97.8 mm) fell during the first week of June 
and undoubtedly washed away nymphal exuviae. The water level of 
Panther Creek rose four feet during this time. The effect of high 
water on emergence is unknown; however, emergence continued 
