Symbiotic Relationship of the Miami Blue Butterfly Larvae and Antsby Lauren Hartigan

Miami Blue Butterfly:
The Miami Blue butterfly,Cyclargus thomasi bethunebakeri, is an endangered species of the lycaenid family that is native to southern Florida (5). The species inhabits mostly tropical costal areas or areas with beachside scrub or tropical pine rocklands (5). Over the past few decades the Miami Blue populations have been rapidly declining (5). Today only a small localized population remains inside a natural conservation area at Bahia Honda State Park in the Florida Keys (5).

Miami Blue Larvae:
The Miami Blue lay their eggs starting from early February through November (5). During the winter the Miami Blue enters into a dimorphic phase, where their metabolic rate decreases (6). They tend to lay their eggs on either the pods of developing fruits of the balloon vine, Cardiospermum, or the growing flower buds of the gray nickerbean plants, Caesalpinia bonduc (6). This egg placement is key. When the larvae hatch it ensures that they will be able to receive an immediate source of nutrients. Some eggs are also laid directly in an ant nests (5). These larvae have to travel to find food sources, but are almost guaranteed protection from the ants (4). Recently hatched larvae usually take on an either green or black coloring (6). As wingless larvae this helps camouflage the insects from predators (4). As adults the larvae grow wings that take on a florescent blue coloring (5).

Ant species:

The Camponotus floridanus ant species is also a native species of Florida (6).They are usually found most active at night and are usually found feeding on many plants native to the area including both plants that the Miami Blue usually lay their eggs on (6). In almost all surviving populations of the Miami Blue, this ant species has been found within the area. Usually two or three ants will protect any one larva (6). Although studies have been done to see if other ant species associate with the Lycaenid larvae the most dramatic connection seems to come from the Camponotus (6). Once the larvae enter into a pupae stage the ants no longer associate with the Miami Blue (5). In adulthood the two species have shown no signs of sharing any kind of remaining symbiotic connection (6).

History of the Lycanid Ant Symbiosis: Ant and butterfly symbiotic relationships date back millions of years (1). The first known fossil was found in Dominican amber and shows direct evidence that prehistoric butterfly like larvae contained glands capable of producing sugar secretions (1). This indicates that there was most likely a symbiotic association back then between ants and butterfly larvae. It suggests that this association has been communicated for years and has continued to this day (1).
There is mutualistic relationship between the lycanid and ant species (2). The lycanids produce a sugary‐amino acid filled secretory liquid that feeds the ants (2). The Nutrients in the liquid provide some sort of nutritional value for the ants (2). Potentially the availability of this easy‐access nutrient supply may have added to an increase in the symbiotic behavior and the continued growth of the two species (2). With the presences of one species there is a need and a potential for the need of the other species.

The ants primarily are there to protect the immature larval stage of the Miami Blue species (5). This more recent symbiosis seems to have aided in the continued reproduction of the Miami Blue (5). The larvae stage for the butterfly is extremely significant, because it provides the nutrients for the insects to enter into a pupal stage and mature into adulthood (4). Also at the larvae stage the insect is the most vulnerable and has no defense mechanisms (5). However, when the lycanoids reach adult maturity there is no longer any need for the ants (4). The ants presence never harms the butterfly (4).
Symbiotic Relationship:
There are recorded symbiotic interactions between various species of lycaenids and ants that include mutualism, commensalism, and parasitism (4).The ant and lycaenids mutualistic relationship is based on the ability for the lycaenid to produce sugary secretions (4). The ants will eat and harvest the sugars produced and then in turn they provide protection for the larvae. They do so by chasing off other predators and parasites (4). This helps the ants gain enough food to survive and it allows more lycaneid larvae to remain safe from the harm of other organisms (4). The commensal relationship between the lycaenids and the ants are found when lycaenid eggs are placed into an ant nest (4). When the larvae fully form they are already in environment where there is protection from the ants and a steady food supply (4). This realtionship provides no benefit for the ants, but really aids in the health and growth of the Lycaenid larvae. A parastic relationship is formed between the two species when the larvae utilize a different kind of signal that makes ants believe that they are apart of the nest (4). The ants will pick up the signal thinking that the larvae are one of their own and proceded to carry the larvae back to the nest. Once the larvae are their they are undetected and begin to feed on the brood of the ants as well as the ants food supplies until it can fully mature (4). This shows signs of predation because not only is the larvae consuming the ants food supply they are also feeding on the young brood of the ants.

Recent studies indicate that the larvae of the Miami Blue share a specific facultative relationship with the ant species Campontus floridanus (2). It has been estimated that about 75% of the known populations of the Miami Blue associate with these ants, but it is unknown to what degree the two species affect each other. Some scientists suggest that the relationship is mutualistic where as others presume it to be parasitic (5). The larvae have to exude a metabolic expense by producing sugary secretions for the ants (4). The secretions seem to be induced by the presence of the ant tending (6). Either way the matabolism that is used to produce the sugar liquid seems to be offset by the survival of the larvae species (5). The major symbiotic benefit is most certainly the aid of the ants from warding off enemies. The ants large size and numbers appears to be a natural benefit for the larvae protection (5). As far as the ants species there seems to be no major harm in the symbiotic relationship. These ant‐tending larvae have been monitored to see if there is a reduced pupal mass, but there has been no proven affect (6). Although the secretions do provide some nutritional value for the ant‐species it is unclear if the secretions provide a sufficient nutrient source for the ants (6). The ants may be living off a nutrient poor diet and may only remain because of other certain stimulating signals (6). It may also be possible that because the ants are protecting the larvae species they are able to gain a high nutritional value and therefore the secretions they omit have a good amount of nutrients (6).
Signaling Process:
The signaling process between the ant and butterfly species involves the use of highly specialized organs (5). The Miami Blue larvae utilize a specialized organ to omit signals that either draw the ants to them or send them away (5). The ants pick up these signals and will act accordingly. What is known is that when the larvae produce a positive signal the ants begin to tend for the larvae (5). The two main organs on the Lycaenid larvae that are in use are the dorsal nectary organ that is in associated with perforated cupola organs on the abdominal side of the larvae body and tentacular organs. The tentacular organs were found producing signals on the abdominal side of their bodies (5). The ants are first stimulated by the tentacular signals, but then remain because of the sugary‐rich secretions that the larvae produce in the dorsal nectary organ (5). The ants consume the sugary liquid and then remain to continue to feed off of it (5). The ants do need other outside food sources, but they can sustain themselves off of the sugar secretions for some time (2). The ants then remain close to the larvae and ward off any predators or parasites that try to bother the larvae (2). In many ways the ants act as the bodyguards for the larvae (2). This presumably aids in the survival rate of the larvae (2). Some studies are now suggesting that this symbiosis is becoming more obligatory because of the dwindling rate of the Miami Blue species (5).   This image shows the signaling pathway the butterfly larvae use to attract the ants. They release phermones that can be recieved by the ants. This image shows the signaling pathway the butterfly larvae use to attract the ants. They release phermones that can be recieved by the ants.

Resources:1. Devries, P. J., and G. O. Poinar. "Ancient Butterfly-ant Symbiosis: Direct Evidence from Dominican Amber." The Royal Society 264 (1997): 1137-140. Print. 2. Jordano, D., and C. D. Thomas. "Specificity of an Ant-lycaenid Interaction." Oceologia 91.3 (1992): 431-38. Print. 3. Leimar, O., and A. H. Axen. "Strategic Behavior in an Interspecific Mutualism: Interactions between Lycaenid Larvae and Ants." Animal Behaviour 46.6 (1993): 1177-182. Print. 4. Pierce, N. E., and W. R. Young. "Lycaenid Butterflies and Ants: Two-species Stable Equilibria in Mutualistic, Commensal, and Parasitic Interactions." The American Naturalist 128.2 (1986): 216-27. Print. 5. Saarienen, E. V., and J. C. Daniels. "Miami Blue Butterfly Larvae (Lepidoptera: Lycaenidae) and Ants (Hymeoptera: Formicidae): New Information on the Symbionts of an Endangered Taxon." The Florida Entomoligist 89.1 (2006): 69-74. Print. 6. Trager, M. D., and J. C. Daniels. "Ant Tending of Miami Blue Butterfly Larvae (Lepidoptera: Lycaenidae): Partner Diversity and Effects on Larval Performance." The Florida Entomoligist 92.3 (2009): 474-82. Print.