The Crambidae are a family of Lepidoptera (moths). They are quite variable in appearance, the nominal subfamily Crambinae (or grass moths) taking up closely folded postures on grass-stems where they are inconspicuous, while other subfamilies include brightly colored and patterned insects which rest in wing-spread attitudes.

In many classifications the Crambidae have been treated as a sub-division of the Pyralidae or snout-moths. The chief difference is a structure in the ears called the praecinctorium, which joins two tympanic membranes in the Crambidae, and is absent from the Pyralidae. It would seem to be a matter of personal opinion (therefore not susceptible to definitive decision) whether this distinction merits division into two families, or whether the common presence of ventrally-located ears should unify them into one family. The latest review by Munroe & Solis, in Kristensen (1999) retains the Crambidae as a full family.

Harmful Crambids

Crambid larvae are typically stem borers in plants of the grass family. As this family contains many important crops, some Crambidae species achieve pest status. The European Corn Borer Ostrinia nubilalis is perhaps the best known – introduced to the USA in the early 1900s, it is now widespread in all but the westernmost states. Other pest species include:

  • Asiatic Rice Borer Chilo suppressalis
  • Sod Webworms Crambus spp.
  • Sugarcane Borer Diatraea saccharalis
  • Bean Pod Borers Maruca spp.

Beneficial Crambids

  • Waterhyacinth moth Niphograpta albiguttalis used to control its host (Eichhornia crassipes), in Florida