50 Nebraskaland • December 2022
MIXED BAG
The khapra beetle (Trogoderma granarium) is an exotic
invasive insect pest of stored grain, grain products and
seeds. The beetle is one of the 100 worst invasive species
in the world, causing up to 70 percent grain damage when
present. It is currently not known to occur in the U.S., though
infestations have been found and eradicated a few times in
the last 80 years. Khapra beetles are regularly intercepted
at U.S. ports of entry in a variety of commodities including
seeds, spices, other foodstuff s, burlap bags, wooden crating
and other shipping containers.
Khapra beetles pose a signifi cant threat to agriculture
in Nebraska, which is why the Nebraska Department of
Agriculture annually conducts khapra beetle surveys
statewide. The insect itself could cause signifi cant economic
losses to the state by damaging stored grain, grain products
and seed. A khapra beetle establishment in the state would
also severely impact both interstate and international trade.
The khapra beetle is a tiny brown to black beetle covered
with fi ne hairs. Larvae are creamy white when young and
age to brown before pupating and are also covered in hairs.
Khapra beetle larvae can look very similar to other common
stored grain pests, and a microscope is used to confi rm
identifi cation.
Larvae are the primary cause of feeding damage. Complete
development from egg to adult can take from 26–220 days,
depending on environmental conditions. If temperatures
drop too low, or conditions become unfavorable, larvae can
enter diapause, where they become inactive and may remain
in this state for months or years.
The NDA annually conducts khapra beetle surveys across
the state to watch for this invasive pest. The survey focuses
on international markets that may stock khapra beetle host
materials which originate in foreign countries. High volume
grain and seed importers and exporters are also surveyed. To
date, all surveys have been negative.
For more information on the khapra beetle, visit
Aphis.USDA.gov/aphis/resources/pests-diseases/hungry-
pests/the-threat/khapra-beetle
KHAPRA BEETLE
By Julie Van Meter, State Entomologist,
Nebraska Department of Agriculture
Khapra beetle larvae and adult.
MINISTRY OF AGRICULTURE AND REGIONAL DEVELOPMENT, BUGWOOD.ORG
PEST AND DISEASES IMAGE LIBRARY, BUGWOOD.ORG
