Trogoderma variabile
The Warehouse beetle, Trogoderma variabile.
Trogoderma variabile, the warehouse beetle is a pest of stored seed, grain and nuts. It is also a pest of museums and occasionally dried pet food outlets. This beetle originates in Asia and now can be found across the Northern hemisphere and southern Australia. The larvae of Trogoderma variabile eat a substantial amount of stored grain in their long lifespan. The stored grain infested by the warehouse beetle becomes inedible and wasted.
Biology of Trogoderma variabile, The Warehouse Beetle.
Views from top and bottom of adult and larva Trogoderma variabile, Warehouse Beetle
[Image credit: University of Nebraska, Lincoln, Department of Entomology]
Adults are around 4mm in length and are dark brown in colour. Adult lifespan is about 2 weeks. Larvae of these species are around 8mm in length and are hairy with a white-light brown colour. Trogoderma variabile larvae can survive up to 6 months without food, and up to 6 years when food is in good supply. It can shed their skin up to 10 times during growth. Mature female lays egg within the first 4 days after emergence. The total life cycle from egg to adult is 37-40 days in a suitable climate.
Damage Caused by Trogoderma variabile, The Warehouse Beetle.
The larvae of Trogoderma variabile, The Warehouse Beetle eat a substantial amount of stored grain in their long lifespan and excrete over the remaining grain and husks. Thus the stored grain infested by the warehouse beetle becomes inedible and wasted. When the larvae moult, their skins mix with the grain. It can act as an irritant in the intestines and skin if consumed. In case of inhalation it could trigger asthma, especially in young children. Adult warehouse beetles are capable of chewing through plastic, foil and airtight containers. It is reported that warehouse beetle causes 33-35% grain damage in grain stores. There are trade restrictions on food contaminated with this pest.
Larval Skins associated with Trogoderma variabile infestation.
[Full credit for image: Agriculture Western Australia]
Pheromone Traps for Trogoderma variabile, The Warehouse Beetle.
Russell IPM manufactures and supplies a complete monitoring system, Xlure-MST for Trogoderma variable. This trap can be used to assess the severity of an infestation of Trogoderma variable before it becomes serious. It can also be used to monitor the effectiveness of any control measure being used to treat an infestation of Trogoderma variable. The Xlure-MST is a multispecies trap based on insect pheromones and food lures.