Order Lepidoptera Description

Most Lepidoptera are completely terrestrial.  There are a few species that feed on aquatic plants above the surface of the water, but there is only one family, Pyralidae, that is truly aquatic.  These aquatic insects are appropriately called aquatic moths.  Aquatic moths feed on submerged vegetation located in a wide variety of aquatic habitats.  Lepidoptera have been documented in streams, ponds, and marshes.

Lepidoptera Family:


PyralidaeFamily Pyralidae

Aquatic Moths

Pyralids are moderately tolerant to low water quality, and they belong to the shredding feeding group. Aquatic moths are most frequently found in ponds, streams, and marshes. Larval size is variable. The average body length is 3 to 35 mm. Pyralids are similar in appearance to terrestrial caterpillars with the exception of some species that possess lateral gills. Larva are most easily distinguished from terrestrial larvae by the presence of tiny hooks, or prolegs on the abdomen. Some Pyralids build cases similar to the Trichoptera, while others do not.


Life History
Lepidopteran larvae can be distinguished from terrestrial larvae by the presence of abdominal prolegs, and the presence of filamentous gills, or portable case. 

Adult Lepidoptera are characterized by overlapping scales on the two pairs of wings, as well by the presence of a sucking proboscis.  The adult female generally deposits eggs just below the water’s surface.  Eggs are laid singularly are in clusters depending on the

Feeding Habits

Most larvae mine or bore into the stems or leaves of aquatic submerged plants.  The feeding mechanism may change based on the instar.


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