</s> ▁D ip tera ▁is ▁an ▁order ▁of ▁wing ed ▁insect s ▁commonly ▁known ▁as ▁f lies . ▁D ip tera , ▁which ▁are ▁one ▁of ▁the ▁most ▁successful ▁groups ▁of ▁organ isms ▁on ▁Earth , ▁are ▁very ▁diverse ▁bi olog ically . ▁None ▁are ▁truly ▁marine ▁but ▁they ▁occup y ▁virt ually ▁every ▁terrest rial ▁n iche . ▁Many ▁have ▁co - e vol ved ▁in ▁association ▁with ▁plants ▁and ▁animals . ▁The ▁D ip tera ▁are ▁a ▁very ▁significant ▁group ▁in ▁the ▁decomposition ▁and ▁deg ener ation ▁of ▁plant ▁and ▁animal ▁matter , ▁are ▁instrument al ▁in ▁the ▁break down ▁and ▁release ▁of ▁nut ri ents ▁back ▁into ▁the ▁soil , ▁and ▁whose ▁lar va e ▁supp lement ▁the ▁di et ▁of ▁higher ▁agr arian ▁organ isms . ▁They ▁are ▁also ▁an ▁important ▁component ▁in ▁food ▁ch ains . ▁ ▁The ▁applied ▁significance ▁of ▁the ▁D ip tera ▁is ▁as ▁disease ▁vectors , ▁as ▁agricult ural ▁p ests , ▁as ▁pol lin ators ▁and ▁as ▁bi ological ▁control ▁agents . ▁ ▁Hab itats ▁D ip tera ▁occur ▁all ▁over ▁the ▁world ▁except ▁in ▁regions ▁with ▁permanent ▁ice - cover . ▁They ▁are ▁found ▁in ▁most ▁land ▁bi om es ▁( all ▁ 1 4 ▁W WF ▁major ▁habitat ▁types ) ▁including ▁desert s ▁and ▁the ▁t und ra . ▁In sect s ▁are ▁the ▁most ▁diverse ▁group ▁of ▁Ar ctic ▁animals ▁( about ▁ 3 , 3 0 0 species ), ▁of ▁which ▁about ▁ 5 0 % ▁are ▁D ip