Butterfly Abundance and Oviposition at the Northern Costa Rica Farm

 The results from the butterfly abundance study in Costa Rica were unexpected and very

surprising. With the number of eggs deposited in the north central Florida trials ranging from

several hundred to almost one thousand during the 10-day experiment, finding absolutely zero

eggs during the Costa Rica trial is perhaps as interesting as if there were hundreds of eggs found.

There are several factors that may contribute to this overall lack of oviposition.

 One explanation has to do with the extreme competition among host plants in the tropical

environment. As stated before, butterflies make tremendous use of visual stimuli to locate host

plants, particularly the color and shape of the host plants' leaves (Stanton 1984). Furthermore,

relative abundance of host plants in an area has been shown to affect landing frequencies by

gravid female butterflies (Courtney & Forsberg 1988). Consequently, the tremendous diversity

of plants in the rainforest, some as host plants for these species, others with similarly shaped and

colored leaves, could have acted as competition towards the potted plants placed out in this

experiment. With the experiment lasting 10 days, perhaps this was too short of a duration for

butterflies to recognize and learn the location of such host plants in a sea of both nearly identical

and intricately complex stimuli.

 Seasonality may have played a part in the visual homogeneity of the landscape as well.

This experiment was conducted during the rainy season in Costa Rica and, thus, there was little

to no flowering exhibited by the plants. According to Janzen (1967), tropical plants in

Guanacaste, Costa Rica, flower and fruit in the dry season due to the fact that investing into non-

vegetative activity is least detrimental to their vegetative competitive ability when rains are less

frequent. The presence of flowers may have increased oviposition by providing another visual

cue for the butterflies, which may have yielded oviposition on the host plant.