Chemical Signaling

Trail of Ants

Chemical signaling is common amongst a wide variety of species, whether it is designed as defense, attracting a mate, or communicating. Insects use different chemicals such as pheromones, allomones, kairomones, attractants and repellents to their advantage of signaling. Chemical signaling is also common in plant insect interactions, which will be discussed in this post. Alongside of that, a narrower topic of the reduviid Apiomerus pilipes, who preys on meliponine bees causing them to have to use their chemical signaling attributes. In the long run, this can be detrimental to their safety.

Chemical signaling works in various ways with species “interactions, mutualism and parasitism, predator-prey cycles, and community assembly” (Raguso et.al, 2015) Chemical ecology is composed of organic compounds that allow species to do various things. In defense, insects, plants, and other species put out protections, such as toxins, anti-nutritives, resin, inks and latex. (Ragusto et.al., 2015) The most common way we know of chemical signaling is through communication such as cues and signals. Cues are common among species to allow for proper habitat selection, foraging, avoiding predators, mating and some cases territorial behavior for better survival. Commonly, this would be considered instinct among human minds. Chemical, however, are what produce those inside the minds of species, even insects.

Insects use pheromones to contact a mate or locate another of their species. Ever wonder how ants are so good at follow the leader? Ants have exocrine glands that secrete pheromones to allow the ants behind them to know where to go. (Attygalle, Morgan, pg. 245) Pheromones are in the category of semiochemicals, which are used for interspecific communication. Another example are allelochemics, which are known as allomones, kairomones, and synomones. Allomones are chemicals emitted from insects, which are designed for defense and repellent secretions, kairomones are what allow a predator to locate a prey and, synomones are beneficial to both producer and recipient, usually of different species. These are all part of insect interactions. An example of kairomones, would be the beetle Hellumorphoides texanus picking up the trail of the army ant Neivamyrmex nigrescens in which they feed upon. Allomones would refer to the defense of the Ladybird beetle, who secrets a chemical to reflect blood and keep itself from being eaten.

Plants also have their own way of chemical signals that they use for protection. When the Ips pini or Ips Paraconfusus bark beetles attack a stressed ponderosa pine, it secrets a thick resin, known as sap, to try to defend itself and drown out the beetles. However, the bark beetles pick up on the chemicals the distressed trees give off to know there is a host nearby. Others have constitutive defense alongside of chemical ones that are “built in” like thorns or hairs. Although we often consider insects to be detrimental to plants, they are benefit with plant-insect interactions. Commonly known as pollination. There is some research done to see if private signals are given off so certain insects know where to go, such as mutualism of the fig wasp to the fig. However, general pollination is more preminant. (Raguso, et.all, 2015) Some toxic plant defense chemicals, such as cyanogenic, glycosides, glucosinolates, ect) serve a multipurpose for butterflies, allowing not only protection from prey but for feeding, oviposition stimulants, and sex pheromones. These butterflies overcome the toxins and benefit from it. Alongside of that, the development of the leafminer Amauromzya flavifronus, was shortened by parasitoids that preyed on that particular species. These are were found on Saponaria officinalis and Silene latifolia, who were grown in different nitrogen levels. (Uesugi, 2015) These are all in one cycle. The leafminer eats the plant, the parasitoid eats the leafminer and the plant gets a partner along with its own defenses. There is some symbiotic relationship between plant and insect chemical signals, and that can be seen in nature.

To be more specific in realm of chemical signaling, the Apiomerus pilipes which preys on Mellpininae bees, uses it attributes to aid in killing. A general study was done on the aspect of predator-prey interactions and the results weren’t specific to chemical signaling but it is still present. One of the observations that was made, was am A. pilipes that tried to prey on a M. seminigra merrillae. When it attacked, the bees tried to swarm and bring the predator into their hive. The act of defense is a chemical signal. They made the attempt to attack and in the long run, the A. pilipes ended up killing three bees and taking one.

Reduviid preying upon Stingless Bee

Chemical signaling is found all over the Animalia and Plantae kingdoms. Chemical signaling is important for communication, mating, and other interactions but can also be detrimental for some. Predators can pick up on the pheromones of their prey to locate them and others uses the chemicals given off by plants for safety and reproduction. Chemical ecology is a complex area of study but it is important to the world today.   

Sources:

La Silva, Alexandre Colletto, and Helcio R. Gil-Santana. Pr Edation of Apiomerus Pilipes (F (2004): n. pag. Web. 25 May 2016.                         

Attygalle, Athula B., and David Morgan. "Chemical Society Reviews." Chemicals from the Glands of Ants - (RSC Publishing). N.p., n.d. Web. 26 May 2016.

Raguso, Robert A., Anurag A. Agrawai, Angela E. Douglas, Georg Jander, Andre Kessler, Katja Poveda, and Jennifer S. Thaler. "The Raison D'etre of Chemical Ecology." N.p., 2015. Web. 26 May 2016.

Uesugi, Akane. "The Slow-growth High-mortality Hypothesis: Direct Experimental Support in a Leafmining fly." Ecological Entomology. N.p., 2015. Web. 26 May 2016.