1988] 
Cornell, Stamp, & Bowers — Hemileuca lucina 
49 
account all three characteristics listed above. Individuals were 
ranked according to total distance traveled (over 5 trials) and the 
cumulative percent of distance traveled plotted against the cumu- 
lative percent of the individuals per group. If all larvae traveled the 
same distance, a plot of this would yield a diagonal line from the 
origin to upper right (e.g. a Lorenz curve with a Gini coefficient = 0). 
The degree of deviation from the diagonal is a measure of inequality 
and is evaluated by the Gini coefficient, where 0 indicates all indi- 
viduals are equal in distance traveled and a maximum of 1 repre- 
sents complete inequality (i.e. all individuals but one having a value 
of 0; Weiner and Solbrig 1984). 
Thus, when inequalities in distance traveled were present, the 
Lorenz curves and Gini coefficients provided a means to assess the 
degree to which the inequalities change from instar to instar and 
relative proportion of individuals responsible for these inequalities. 
For example, a high Gini value would indicate that a few individuals 
traveled either a small distance or quite far relative to the others and 
those two possibilities can be distinguished by the shape of the 
curve. 
Results 
Individuals usually did not change ranks after half way through a 
trial (Table 1), although a few individuals turned around or passed 
others. For half the tests (9 of 19), ranks of individuals, as deter- 
mined by distance traveled, were stable from trial to trial (Kendall’s 
coefficient of concordance, Table 2). Total distance traveled in each 
instar was not correlated consistently with larval weight (Table 3) 
and therefore we concluded that distance traveled was unrelated to 
larval size. 
Total distance traveled by each larva was compared between 
instars to determine whether those inequalities in distance traveled 
within an instar persisted into the next one. In most instances, total 
distance traveled in one instar was not correlated with distance 
traveled in the previous instar (Table 4). When a significant correla- 
tion occurred, it was between the third and fourth instars and 
between the fourth and fifth instars. 
The pattern of considerable variation in distance traveled among 
larvae is illustrated graphically by the Lorenz curves, which show 
the inequalities in total distance traveled in 5 trials by individuals in 
