Location: Stored Product Insect and Engineering Research
Project Number: 3020-43000-034-022-A
Project Type: Cooperative Agreement
Start Date: Sep 19, 2025
End Date: May 31, 2026
Objective:
Objective 1: Determine operating conditions feasible for commercial stored product heat treatments for T. granarium by observation of active facilities.
Objective 2: Determine susceptibility of T. granarium to heat treatment in multiple seed commodities.
Objective 3: Initiate heat treatments in desired commodities under commercial operation standards.
Approach:
Objective 1. Australia has defined parameters for heat treatment for khapra beetle, and there are facilities in Greece being designed in an effort to meet these standards, based on the Australian standards, but also the requirements of ISPM 15 protocols.
We will travel to visit these facilities and obtain detailed information concerning their operation. We will obtain information about equipment used for such treatments (heaters, fans, tarps, temperature sensors), as well as typical load volumes and the range of products treated.
The information obtained from the facility will be communicated to the APHIS S&T TMT unit for review of the procedures and recommendations for adjustments of equipment or protocols for research scale experimentation will be discussed with the lead cooperators. We will then construct a research-ready shipping container housed in Greece.
Objective 2. Performing these trials in Greece will allow an increase in the number of organisms tested. Fifty diapausing larvae will be exposed to the 3h 60°C heat in approximately 100g of the following commodities: 1) Wheat Berries, 2) Watermelon seeds, 3) Corn Seeds, 4) Lentils, 5) Control (Wheat Berries not heat-treated). There will be at least five replicates of these treatments. The insects will be selected from lab colonies where larvae remain alive after all of the food resources after six months. For treatments 1-4, the insects will be given 2 days to acclimate and feed before the treatment. After 1 d of heat, insects will be removed and evaluated for mortality. This protocol will allow for the evaluation of 250 insects total per commodity and over 1000 insects overall. The results of this experiment will be communicated to ARS for discussion.
Objective 3. Separate treatments will be carried out in commercial ISPM 15 units that also apply the Australian protocols, with vials containing at least 100 larvae, as well as different life stages of T. granarium, along with the commodity. Commodities will be wheat berries and watermelon seeds. After the termination of the treatments, the vials will be the vials will be taken to the University of Thessaly, to estimate mortality and progeny production capacity.
Next, the experimental conditions observed at the heat treatment facilities will be duplicated to the greatest extent possible at the University of Thessaly, using shipping containers. Initially, buckets with 20 liters of the commodity will be placed within the container that are infested with khrapra beetle larvae and adults. There will be a 5 d acclimation period before treatment. The experiment will be repeated twice. We anticipate following the guidelines for the Australian government parameters for heat treatment, which is 3 hours at 60°C, but may adjust the protocol depending on the results of previous small-scale chamber experiments. Temperature readings will be taken within the commodity buckets and within the air space of the container. The dead beetles will be counted according to life stage, but the contents of the bucket will not be discarded for two months to preclude the potential development and reproduction of any undetected survivors.