Living With Grain Storage Pests

Lesser grain borer
USDA photo: Paul Finn

Grain elevators are used to store grain for future shipment. Large concentrations of grain in protected conditions create an ecosystem for insect colonization. The pests vary with geography, but many pests are distributed globally, having made their way around the world hitching rides on stored grains. The Canadian Grain Commission had no problem generating a list of twenty “Primary” beetle pests of grain:

Stored product beetles found in Canada
• Larger grain borer
• Lesser grain borer
• Bean weevil
• Pea weevil
• Southern cowpea weevil
• Granary weevil
• Rice weevil
• Maize weevil
• Khapra beetle
• Rusty grain beetle
• Flat grain beetle
• Flour mill beetle
• Merchant grain beetle
• Sawtoothed grain beetle
• Longheaded flour beetle
• Red flour beetle
• Confused flour beetle
• Large flour beetle
• Cadelle
• Angoumois grain moth

Many of these beetles were pests of stored grains prior to the invention of the grain elevator in 1842. Grain produced in the Midwestern US was shipped by boat to the port of Buffalo, NY to be loaded onto barges for New York City. Grain was stored in barrels which were expensive and heavy to unload or in bulk. The unloading of bulk grain from ships was time consuming and tie a boat to port for days.

Buffalo residents, Joseph Dart and Robert Dunbar designed and built the first grain elevator in 1842. It used a steam engine to drive a line of buckets. Longshoremen shoveled grain into the buckets entering the boat. The conveyer lifted the grain-filled buckets into a tall building where the buckets could empty into storage bins. Chutes in the building allowed for rapid unloading of grain into barges or wagons. The invention of the grain elevator reduced the time needed to unload grain from ships from a week to a matter of hours.  Dunbar continued the lucrative business of designing and building grain elevators throughout North America.

The first shipment of grain loaded into the first elevator likely contained one or more species of grain beetles. Thus, the opening of the first grain elevator ushered in the first grain elevator pests to colonize the newly built ecosystem.