1973] 
Young — Parides areas mylotes 
3 
radically several days each month over a 14-month period. At Tirim- 
bina, it was studied systematically 14 days over a two-month period. 
Life cycle studies consisted of the description of life stages and 
the estimation of egg-adult developmental time under “laboratory” 
conditions. These measurements were made on individuals reared 
on a natural food plant, and eggs were obtained in one of two basic 
ways. The first method was to collect eggs witnessed to be ovi- 
posited in the wild ; this method was employed primarily in the 
Tirimbina studies and to a lesser extent in the earlier La Selva 
studies. The second method was to obtain eggs by hand-pairing 
newly-emerged adults, using the technique of Clarke (1952) for 
Papilio machaon, or allowing mating to occur in pairs of adults 
confined to plastic bags. The latter technique is useful to obtain 
estimates of fecundity in this species (Young, 1972a). Both methods, 
obtaining eggs in the wild, and mating females in the laboratory with 
subsequent induction of oviposition, are very successful for this 
species, provide large numbers of eggs for rearing studies. Combining 
both methods, a large number of individuals were reared from La 
Selva (primarily through the laboratory mating method) and a lesser 
number were reared from Tirimbina. The “laboratory” for the La 
Selva studies consisted of a well-ventilated room in an apartment in 
San Jose, while the “laboratory” for the Tirimbina studies was a 
room in a different apartment, located about 1.5 km from the first. 
In both cases, air temperature usually varied between 2i-23°C and 
the humidity was about 45%. 
The techniques for rearing immatures of this butterfly are given 
in Young (1972a) for La Selva individuals, and essentially the same 
methods were employed for the Tirimbina studies. 
The larval food plant acceptance studies were conducted from 
individuals obtained at Tirimbina during 1972. This study consisted 
of offering first instar larvae immediately after hatching, in the 
laboratory, fresh clippings of several species of Aristolochia from 
various sources. The rationale was to offer separate small groups 
of young larvae various species of Aristolochia including species 
known to be natural food plants. Larvae on each food plant were 
then scored for survival rate and body size. There were five species 
of Aristolochia that were called “novel” food plants in addition to 
the two natural food plant species. Two experiments were con- 
ducted in San Jose: in each of these, 12 larvae were reared on the 
natural food plant and 13 were reared on each of two “novel” food 
plants collected from different localities in Costa Rica. The remain- 
ing three food plants were tested at Lawrence University during 
