14 
Psyche 
[March-June 
able, when mated females of this butterfly lay eggs in the laboratory, 
there is usually a tight clustering of eggs (Young, 1972a). Thus 
tight clustering of eggs (the arrangement of eggs into a group where 
the eggs touch each other) can be induced in the laboratory when 
females are confined individually or in low numbers to plastic bags 
containing clippings of the food plant. Such clustering, however, is 
seldom found in the wild in this butterfly and other species of 
Parides. 
The larvae of P. areas mylotes exhibit several behavioral patterns 
that warrant more intensive study. Upon hatching the larva in- 
variably eats its emptied egg shell, and then moves a considerable 
distance to the closest youngest leaves. Locomotor movement is ac- 
companied by the production of silken treadwork on which the larva 
crawls from one place to another. Although small groups of larvae 
are frequently found in the field (Fig. 2-E, F) there is no evidence 
for gregarious habits among the individuals in a group. All individ- 
uals on an individual vine generally feed at the same times of day, 
but there is no indication of coordinated locomotor movements among 
the individuals. Furthermore, single or doublets of larvae are also 
frequently encountered in the field. Larvae of all instars are gen- 
erally inactive at night. The extent of larval dispersion when several 
eggs are laid on a vine may be governed by the size of the vine. For 
example, it is not uncommon to find one or two fourth or fifth instar 
larvae present on a young vine ( 1-2 m tall) in the field, and in cases 
where there are two present, these individuals are often found to- 
gether on the same stem. Both in the field and laboratory, older 
larvae eat the stems of young Aristolochia vines (Fig. 3-C). On 
very large vines in which woody tissue is well-developed, older larvae 
are generally confined to feeding on leaves and it is unusual to find 
two or more individuals resting close together. Group formation is 
frequently encountered only in the younger larvae (first and second 
instars) and in cases where larger (older) larvae are clumped, this 
is most likely due to the fact that they are feeding on a young vine 
and the food supply is limited. It is not known if Parides larvae 
crowded on young Aristolochia vines will leave the vine in response 
to intense crowding. The osmeteria of the larvae of swallowtail 
butterflies are functional defense organs. Predatory attack on the 
larvae of P. areas mylotes in the wild has not been observed to date. 
The defensive strategy of the larvae against predators includes 
( 1 ) possession of conspicuous body coloration in which the dark 
body and pattern of white tubercles stands out against the light green 
coloration of Aristolochia leaves, (2) possession of an apparently 
