Definition:

Symbiosis is a close ecological relationship between the individuals of two (or more) different species.   Sometimes a symbiotic relationship benefits both species, sometimes one species benefits at the other's expense, and in other cases neither species benefits.

Ecologists use a different term for each type of symbiotic relationship:

Mutualism	--   both species benefit
Commensalism	--   one species benefits, the other is unaffected
Parasitism	--   one species benefits, the other is harmed
Competition	--   neither species benefits
Neutralism	--   both species are unaffected

The following table illustrates the correct use of these terms in interactions between Species "A" and Species "B".

"+" denotes benefit to the species

"0" denotes no positive or negative effect

"-" denotes an undesirable effect of the interaction.

Examples of Symbiotic Relationships in Insects:

Nutritional Symbiosis:

Ambrosia beetles

Termite fungus gardens

Parasol ants

Cockroach endosymbionts

Shelter Symbiosis:

Ant mimics (inquilines)

Slavemaker ants

Gall insects

Transport Symbiosis:

Torsalo (Human bot flies)

Scelionid wasps

Pollination Symbiosis:

Nectar guides

Bottle gentians

Dung beetles and skunk cabbage

Yucca moths

Bumblebees and scotch broom

Fig wasps

Pseudocopulation in orchids

Defensive Symbiosis

Ants and acacias

Aphid farmers