1981] 
Kearns & Yamamoto — Gargaphia 
219 
Table 2. Direction of movement of G. solani aggregations on a host plant 
Female Present Female Absent 
% of groups observed % of groups observed 
Upward 
Directed 
Upward 
Directed 
Feeding Movements 
movement 
movement 
movement 
movement 
In light 
82* 
96* (1) 
78 
100* (2) 
In darkness 
89* 
100* (2) 
100* 
100* (3) 
Light source below 
aggregation 
71 
78 (2) 
75 
67 (3) 
Alarm Response 
In light 
90* 
100* (4) 
62 
67 (5) 
(1) 23 observations 
(2) 9 observations 
(3) 6 observations 
(4) 19 observations 
(5) 12 observations 
* Significant at the 95% confidence level 
from one surface of the leaf to the opposite surface. At no time was 
“herding” by the female observed as described by Fink (1915). 
Movements to a new leaf were difficult to predict and lengthy to 
monitor. Because of time considerations, it was not feasible to make 
a statistical study of the female’s total behavior pattern during these 
group movements. When a female was present, she led the group to 
a new leaf. In the absence of a female, the nymphs moved on their 
own. Females sometimes wandered about on adjacent leaves but 
usually returned to their aggregations. 
ALARM RESPONSES 
When an aggregation of the third through fifth instar nymphs of 
G. solani was alarmed with a squashed fifth instar nymph, the group 
responded quickly, usually within 10 seconds. The duration of the 
response was from 4 to 20 minutes. If the nymphs were on the top 
surface of the leaf they moved to the underside, and conversely. In 
either case, at least some of the nymphs moved quickly to the midrib 
and from there to the petiole of the leaf. At the exit axil, the nymphs 
moved up or down the stem; but they were more likely to move up 
the stem (Table 2, Female Present). During this activity, the female 
