Decomposers, as custodians of food chain

Decomposition is a cyclic process in which organic substances is break down into simple organic matter. Decomposers is the process of nutrient cycle and it is necessary for recycling of finite matter that has physical space.

Decomposers, as custodians of food chainActually, decomposers are responsible for decomposition which break down dead organic matter into minerals, nutrients, water, carbon dioxide and other chemicals which can be gained and consumed by green plants.

Dead organic matter includes animal bodies, animal feces, carcasses, leaf litter, dead wood, and many other substances. Many soil bacteria, fungus, and insect species are involved in decomposition.

Some insect species involved in decomposition are beetles, mites, sow bug, springtails, flies and ants, some other organisms like millipedes, spiders, slugs, snails, are also involved and collectively these called physical decomposers.

Because they grind, suck and chew the material into little pieces.

• Small sizes like Mites (Acari)and springtails from collembolan their size ranges between 100-
200 mm.
• Large insects like beetles (Geotrupidae or Scarabaeidae).
• Diptera larva like Calliphoridae, Sarcophagidae, Muscidae

All these organisms belong to the destruction phase of decomposition. These arthropods insects are usually present in terrestrial habitat. these organisms are high in number as some times millions of individual found in one square the temperate region, these arthropods are major decomposers.

Decomposition of plant remains

Insects play an important role in the decomposition of plant remains. however, some insects lack enzymatic activity required to decompose the organic matter of plant remains. Actually, in case of plants, the presence of cellulose enzyme is necessary to breakdown cellulose in plants which some insects lack.

Many insects solved this problem by making interaction with microorganisms like symbiotic protozoa and some bacteria. external microflora produced cellulose and some insets take advantage of this. For assimilation of wood cockroaches and termites are important well-known decomposers and make symbiotic relation with protozoa and some bacteria.

This difficulty of cellulose enzyme is not presented from all plants, fruits are easily decomposed by arthropods, fruits decomposition is enhanced by presence of yeast. Wasps and flies the best feed on these products resulted from fermentation.

There is an interaction between microorganism, plants, and insects and in some cases close relation between plants and
microorganisms helps insects to consume both.

Decomposers of corpses

Corpses are a rich source of organic matter, and have separate and special microclimatic conditions. insects’ attraction towards corps changes according to climatic conditions. Microphagous insects not only take carrion, as well as make carrion.

  • Fly larvae secret enzymes in carrion.In the case of beetles its larvae and adult both make little tunnels in carrion, which increase microbial activity and aeration.
  • In geographical areas where dipterous and coleopterons species are present, especially in these areas aunts are in abundance, so corps are rapidly removed by these insects.
  • Diptera is the most important decomposers, in case of decomposition of corps. Diptera adults feed on the fluid of corps. Diptera larvae also called true decomposers. because they secrete directly enzymes from carrion and increase liquefaction. These species are very common in rainy season especially in tropical areas, while in the temperate region these are common in early summer.
  • Biology of Diptera species is very simple and common as females of house flies and blow flies lay eggs near natural holes or at base and larvae will move or penetrate in below tissues.
  • Coleopteran, a major group found in temperate regions is siphidae, this group is also like Diptera found to live in carrion. Microporous specie has special behavior in case of Coleoptera, when their female and male come close they burry the carrion. coleopteran reduce colonization of other insects in this way, while once carrion buried in this way they convert the carrion into balls.
  • In neotropical forests, availability of the matter is less for dung beetle, because low availability of dung and large mammals decay. But in African forests large mammals, some herbivorous present so dung beetle presence noticed there. The insects involved in the decay of corpses vary according to the environment and climatic condition.

Decomposers of excrement

The excrement of animals are a rich source of nutrients, insects take part in quick recycling of feces. the digestive system of herbivorous is less efficient than carnivorous because their excrement contains very less material usable by insects.

While excrement of herbivorous are like leaves and easy to digest and usable. More than half of the food that herbivorous animals eat returned to the soil in the form of unassimilated material. Animal dung is the best place for entomofauna , because it has a large amount of organic matter.

In grazing areas, animal dung is the best medium for a dung beetle.
Animal dung is the best habitat for coprophilous species. Colonization of animal dung takes place in three waves by insects.

1. The first wave is when flies come around dung and lay eggs in a large amount.
2. The second wave is many types of beetle habitat on this dung.
3. The third wave is an abundance of mites at this place.

Beneficial Aspects of Insect Decomposers on

Activation or viability of a particular ecosystem depends on its nutrient cycle. Which is definitely a tough process with specific functioning of every organism including decomposers. Humus formation is enhanced by the activity of decomposers. This process will make nutrients available to plants.

The best example can be taken from pasture ecosystem where the system
works properly and dung of cows or other animals is transformed. if this dung cannot be used or transformed, this dung accumulation will cause deleterious effects on soil and no plant growth.

When these pats ignored by decomposers and not removed, they cover this grass area and inhibit growth. Example: In 1981 a report was given by flincher that cattle cover a large area (more than 300 hectares) with dung.

Dung on the surface has very harmful effect for cattle, don’t graze on growth around these pats, and more important nutrients amount lost in this pat, an estimated amount of nitrogen is 80% that lost in this pat.\

But when Dung beetles are present this nitrogen loss even can be reduced by 15%. Dung beetle not only stable nitrogen supply also soil aeration and holding capacity.

More than 2000 million dollars can be saved as potential benefits if cattle dung consumed by dung beetle and rapid burial of this dung takes place. First Time Australia introduced to dig out organic matter from grazing areas in Australia, and dung beetles also used to increase breeding of flies.

Role of Decomposers in Food chain

Decomposers play the role of cleanup crew in the ecosystem. actually, food chains start from photosynthesis than primary consumer eat plants, and net level consumers like secondary can feed on primary and tertiary on secondary. decomposers consume dead matter and add organic matter in the soil.

Decomposers play a vital role in nutrient cycling in the food chain as they return nutrients to the soil. these nutrients obtained from plants including carbon, nitrogen phosphorus, while animals take these nutrients by eating finally decomposers responsibility is to return these nutrients to the soil.

Role of Decomposers in Ecosystem maintenance

Decomposers are considered as the housekeeper of the ecosystem. Without decomposers, dead matter and animals will accumulate and pilling up and nutrients can be recycled. decomposers cleanup environment by removing this dead matter and animal residues. If decomposes are not in ecosystem maintenance of an ecosystem cannot be stable.


Biochemical cycle of the ecosystem can be disturbed if decomposes are not an ecosystem. For the supply of food to plants, animals, humans even every living organism depend on the food chain and nutrient recycling

By waqar zafar

Waqar zafar is a graduate from the university of Agriculture Faisalabad. Major subject opted for his study was Plant Pathology