Increasing global risk of khapra beetle invasion forecasted under projected environmental conditions

The khapra beetle, Trogoderma granarium, is a stored product pest of global concern, readily transported with cargo and reported in over 60 countries, several of which have spent millions in USD to eradicate populations. Despite the profound risk to stored grain commodities, nothing is known about the potential future distribution of species. We utilize MaxEnt and two datasets representing (1) only the historical range and (2) all global locations where it currently is or was established, even if later eradicated, to model areas of suitability under current future climatic conditions under low and high climate change scenarios at close (2040) and distant (2080) time points. The potential distribution using historical data was much reduced compared to the combined model; consequently, all established localities, even if eradicated, change model outcomes and are vitally important when building models. An increase of high potential suitability (> 75% suitable) is projected with greater time and climatic scenarios, primarily in North America and Europe, which have previously eradicated T. granarium. These results call for greater surveillance to prevent T. granarium expansion to inland areas with high grain production and storage where devastating losses would occur.