Restricted distribution. NOT in Australia, New Zealand, nor Pacific islands. Expert identification required. Prefers hot, dry climates.
World’s worst pest of stored grains, nuts, pulses, processed products, and a health hazard. Spoilage from larvae: (i) feeding directly and (ii) cast skins and hairs contaminating consignments causing health and decontaminating issues.
Larvae reddish-brown, hairy, up to 7mm with brush-like hairs at hind end; adults, 2-3.5mm oval, reddish-brown, with fine hairs on the back. Adults suspend activity (diapause) if conditions unsuitable, for up to 9 months.
Spread: infested grains, and other food stuff, processed products, and animal feeds, traded domestically and internationally.
Biosecurity: see draft National Khapra Beetle Action Plan 2020-2030 (Australia) to manage threat: (https://haveyoursay.awe.gov.au/khapra-beetle-action-plan).
Cultural control: hygiene: clean walls (and fill cracks), floors, vents, bins, and use new sacks; clear up spillages; check frequently for infestations and monitor with pheromone traps.
Chemical control: fumigation with methyl bromide (check Montreal Protocol), phosphine, and (in Australia) sulfuryl fluoride for grain and seed storage facilities, and baled hay. Heat (60oC for 30 minutes or 42.5oC for 8 days). Malathion currently approved (in Australia) for infestations in structures and surrounding surface areas.
Pacific Pests, Pathogens, Weeds & Pesticides
Khapra beetle (483)
Trogoderma granarium; previously known as Trogoderma afrum, and Trogoderma khapra.
AUTHOR Grahame Jackson
Information from CABI (2019) Trogoderma granarium (khapra beetle) Crop Protection Compendium. (https://www.cabi.org/cpc/datasheet/55010); and Andras Szito (2020) Khapra beetle - declared pest. Department of Primary Industries and Regional Development (entomology). Government of Western Australia. (https://www.agric.wa.gov.au/biosecurity/khapra-beetle-declared-pest?nopaging=1); and from Akol AM, et al. (Undated) Trogoderma granarium Everts, 1899 - Khapra beetle. BioNET-EAFRINET Keys and Fact Sheets.(https://keys.lucidcentral.org/keys/v3/eafrinet/maize_pests/key/maize_pests/Media/Html/Trogoderma_granarium_Everts_1899_-_Khapra_Beetle.htm#Contact). Photo 1 James D. Young, USDA APHIS PPQ, Bugwood.org. Photos 2-5 Simon Hinkley & Ken Walker (2005) Khapra beetle (Trogoderma granarium): PaDIL - (http://www.padil.gov.au).
Produced with support from the Australian Centre for International Agricultural Research under project HORT/2016/185: Responding to emerging pest and disease threats to horticulture in the Pacific islands, implemented by the University of Queensland and the Secretariat of the Pacific Community.