![Danaine_kleptopharmacophagy](https://upload.wikimedia.org/wikipedia/commons/9/91/Danaine_kleptopharmacophagy.jpg)
Kleptopharmacophagy is a term used for describing the
ecological relationship
In ecology, a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species (intraspecific interactions), or of different species ( interspecific interactio ...
between two different organisms, where the first is stealing the second's
chemical compounds
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
and consuming them.
This scientific term was proposed by Australian, Singaporean, and American biologists in September 2021 in an article that was published in the journal
''Ecology'' by the
Ecological Society of America
The Ecological Society of America (ESA) is a professional organization of ecological scientists. Based in the United States and founded in 1915, ESA publications include peer-reviewed journals, newsletters, fact sheets, and teaching resources. I ...
.
The
phenomenon
A phenomenon ( : phenomena) is an observable event. The term came into its modern philosophical usage through Immanuel Kant, who contrasted it with the noumenon, which ''cannot'' be directly observed. Kant was heavily influenced by Gottfried W ...
was first noticed in
milkweed butterflies
Danainae is a subfamily of the family Nymphalidae, the brush-footed butterflies. It includes the Daniadae, or milkweed butterflies, who lay their eggs on various milkweeds on which their larvae (caterpillars) feed, as well as the clearwing butte ...
that were attacking
caterpillars
Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths).
As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Symp ...
and drinking their internal liquid, proposedly to obtain toxic
alkaloids
Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar st ...
used for defense, as well as for mating purposes.
Characteristics
Kleptopharmacophagy is a generic term and a scientific
neologism
A neologism Greek νέο- ''néo''(="new") and λόγος /''lógos'' meaning "speech, utterance"] is a relatively recent or isolated term, word, or phrase that may be in the process of entering common use, but that has not been fully accepted int ...
, that is used to describe the phenomenon of chemical theft between living organisms.
This special type of behavior is something new for researchers, as it does not match the traditional descriptions of
biological interaction
In ecology, a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species (intraspecific interactions), or of different species (interspecific interaction ...
.
Kleptopharmacophagy cannot be defined simply with a use of classical ecological relationships and their descriptions, such as
predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...
,
parasitism
Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...
and
mutualism.
Besides being an
interspecific
Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species.
Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organi ...
interaction, kleptopharmacophagy can also be seen as a
cannibalizing act (hence an
intraspecific
Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species.
Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organ ...
act),
with adults attacking larvae of their own species.
In butterflies
![Ideopsis vitrea kleptopharmacophagy](https://upload.wikimedia.org/wikipedia/commons/d/db/Ideopsis_vitrea_kleptopharmacophagy.jpg)
Kleptopharmacophagy has only been reported for butterflies in the subfamily Danainae, more commonly known as the
milkweed butterflies
Danainae is a subfamily of the family Nymphalidae, the brush-footed butterflies. It includes the Daniadae, or milkweed butterflies, who lay their eggs on various milkweeds on which their larvae (caterpillars) feed, as well as the clearwing butte ...
. The phenomenon was first described in butterflies that were observed scratching and feeding on live
larvae
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
of other milkweed butterflies.
The initial discovery was made in year 2019 in forests of
North Sulawesi
North Sulawesi ( id, Sulawesi Utara) is a province of Indonesia. It is located on the Minahasa Peninsula of Sulawesi, south of the Philippines and southeast of Sabah, Malaysia. It borders the Philippine province of Davao Occidental and Soccsks ...
, in
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
, when two researchers noticed that milkweed butterflies of different species,
well-known for their toxicity and bright
warning colours (
aposematism
Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or ...
),
were interacting with the larval stages of other butterflies.
The adult insects were attacking and harassing the caterpillars by scratching at them with
tarsal claws on their legs.
The butterflies then imbibed the juices from the wounded caterpillars with their long and curved
proboscis
A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elong ...
.
Caterpillars that were targeted appeared to range from living to dead and dying individuals. Live caterpillars were observed to contort their bodies in an attempt to deter scratching, but usually succumbed to the repeat harassment.
There is also one recorded example of kleptopharmachophagy occurring between two adult butterflies; a male ''
Ideopsis vitrea'' ''vitrea'' was feeding on a liquid, oozing from the wings of the male ''
I. blanchardii blanchardii''.
Role
![Parantica algeoides necropharmacophagy](https://upload.wikimedia.org/wikipedia/commons/a/a1/Parantica_algeoides_necropharmacophagy.jpg)
It is thought that such chemical theft serves at least two roles. By feeding on toxic caterpillars, the adult butterflies acquire additional toxins, which serve as a protection against predation. The stolen toxins, mostly
pyrrolizidine alkaloids
Pyrrolizidine alkaloids (PAs), sometimes referred to as necine bases, are a group of naturally occurring alkaloids based on the structure of pyrrolizidine. Pyrrolizidine alkaloids are produced by plants as a defense mechanism against insect he ...
(PAs), are also of great importance for male butterflies, which use those compounds for producing mating
pheromones
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...
. Additionally such chemicals are components of so-called
nuptial gifts, consisting of male sperm and some nutrients, that are given from males to females during
mating
In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. ''Copulation'' is the union of the sex organs of two sexually reproduc ...
. Significance of the alkaloid use for male butterflies can be demonstrated through observation of male danaine butterflies congregating in large numbers at alkaloid producing plants, where they spend hours fervently scratching and liberating plant juices.
Similar behaviour
Milkweed butterflies have also been previously seen feasting on some moribund
pyrgormorphid grasshoppers
Grasshoppers are a group of insects belonging to the suborder Caelifera. They are among what is possibly the most ancient living group of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago.
Grasshop ...
, that are known to contain toxic alkaloids,
as well as obtaining desired chemicals from carcasses of dead insects of different taxa. Note that in this case, the term necropharmacophagy may be more appropriate, since butterflies feed on the dead animals.
Similar behavior was observed with adult butterflies scratching leaves of different plants that possess various toxins in their vegetative organs (so-called leaf-scratching
). Adult male danaine butterflies use their sharp tarsal claws to scratch and damage leaves of plants that contain high levels of pyrrolizidine alkaloids, thereby liberating the juices for consumption.
Since kleptopharmacophagy was recorded and described only a few times,
it is thought that obtaining such chemicals by feeding on plants with alkaloids is a common and more frequent way of stocking toxins.
Kleptopharmacophagy is proposed to be an alternative way of acquiring these chemicals.
References
Bibliography
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Animal cannibalism
Eating behaviors
Butterflies
2021 in biology