Progress 12/15/18 to 12/14/20
Outputs
Target Audience:The Target audience is anyone who is interested in the field of edible insects for food and feed. This includes entrepreneurs, farmers, startups and investors. Changes/Problems:COVID-19 had significant impacts on the second year of this grant. Progress was inhibited as follows: Yellow mealworm colony was reduced from 800,000 to about 20,000. Green fig beetle colony was reduced from about 40,000 to about 3,000. Western rhinoceros beetle, ox beetle and desert stink beetle colonies were eliminated. An experiment rearing mealworms on fresh food waste was halted. The CatTrap test of the redesign was not carried out. Development of Hyles lineata as an insect crop was not carried out. What opportunities for training and professional development has the project provided?This project trained: Two Masters in Science (MS) students, Meck Slagle and Holly Cope, whose MS Theses were partly supported by this grant. Two technicians, Hunter Clark and Heather Costa, who conducted experiments and learned how to rear and maintain colonies. Nine undergraduate students received training in insects as food and feed: Duaa Albawali, Laura Ruiz, Matt Olenski, Joshua Parmer, Jennifer Ramirez, In Yung (Lennie) Park, Robert Finn, Erin Scott, Holly Cope. Thirteen engineering students worked on the grasshopper harvester supported in part by this grant: Cecilia Stoesser, J.R. Dodge, Jake Vartanian, Angelica Calanog, Lianne Evans, Javier Frasuto, Daniel Shannon, Yukai Xie, Jacob Zall One High School student, J'Hrenara Rios, Science Project was partly supported by this grant. How have the results been disseminated to communities of interest?Two peer review papers acknowledge this grant. Seven media coverages, including one television segment on Arizona Public Media (AZPM) and five community presentations discussed the work carried out on this grant. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The first year of this grant was pre-COVID during which we set up and initiated procedures to meet the grant goals. The second year of the grant occurred during the COVID closure. All goals were severely hampered by COVID as explained below. A main outcome of this project was the establishment of HexaFeast LLC, a startup company developing technologies associated with insects as food and feed industry that will commercialize some of the results described below. This grant tested the efficacy of a habitat centered approach to the insect as food and feed industry. Davidowitz (PI) was asked to be a Special Issue Editor for Current Opinion in Insect Science (COIS) on mass production of insects that will include nine contributions from academics and industry. One of these contributions compares and contrasts the species-centric approach that is most commonly used in the industry with the habitat-centric approach that was developed through this grant. Below are the grant goals for the four habitats and how they were addressed. 1) The goal of the agricultural waste habitat is to streamline the handling time and to determine yield throughout the growing season. We used two species to test this goal. The yellow mealworm (Tenebrio molitor) was used to test mixed fresh food waste. We established a colony containing about 800,000 individuals in year 1 which we had to reduce to 20,000 in year 2 due to COVID. Fresh food-waste consists of fresh green material that has not yet decomposed such as pruned leaves, stems, damaged fruits and vegetables, recently cut plants and spent brewers grains. The University of Arizona Student Union provided about 8,800 pounds of fresh mixed fruit and vegetable kitchen food-waste scraps per week during the academic year. This mixed feed was used to test the efficacy of using randomly mixed combinations of numerous species of fruits and vegetables such as a farmer may collect from neighboring farms, restaurants or packaging plants. It will be advantageous to the farmer if there is no need to construct diets from specific ratios of specific species of fruit and vegetable food-wastes. We found that mealworms reared on combinations of food-waste diets (spent brewer's grains and leafy greens) had similar increases in weight relative to the control larvae reared on wheat bran alone (with the exception of larvae reared solely on leafy greens), and that a 1:1 ratio of wheat bran to leafy greens and spent brewer's grains, respectively, maximize larval growth. Data from the literature suggests that a 4:1 ratio of carbohydrates (C) to protein (P) is the preferred diet for T. molitor. This ratio has not been tested explicitly, however. We found that this ratio is low and T. molitor grows better on higher C:P ratios. This experiment forms the Thesis of Holly Cope, a MS student. The first run of the experiment had to be suspended due to COVID. A second run of the experiment is currently underway. The second agricultural waste stream we tested was decaying organic material. Decaying organic matter is ubiquitous worldwide and a common byproduct on any farm. We leverage this to develop a gradient of four detritivore beetle species that have decreasing decomposing wood and increasing compost requirements in their diets from a high to low elevation. We justify the rationale for the gradient in that different geographic areas will have waste streams with different degrees of wooded material depending on local crops. Using four species in this gradient-approach will ensure that any insect facility will have available, at least one, if not more, potential species to work with. The four species used in this part of the proposal were chosen because they are common local species in Southern Arizona, abundant enough to establish a colony, and are sufficiently generalist so that convergent species, if not the same species, may be found elsewhere in the US where edible insect facilities are located. From high to low elevation we examined the Western Rhinoceros Beetle (Dynastes grantii), the Ox Beetle (Strategus aloeus), the Green Fig Beetle (Cotinis mutabilis) and the Desert Stink Beetle (Eleodes longicollis). We established small colonies of D. grantii, S. aloeus and E. longicollis but had to abandon them due to COVID. We focused our efforts on C. mutabilis. We established a colony of about 40,000 individuals which we had to cut back due to COVID to a colony of about 3,000 individuals. We examined ten different cow manure-based diets mixed with agricultural waste. Our results show that manure compost mixed with mushroom mycorrhizae (waste product of the mushroom industry), yielded the best growth results. This study formed the Thesis of MS student Meck Slagle and has been submitted for review in the Journal of Insects as Food and Feed. 2) The goal of the forest habitat is to perfect the CatTrap and determine tree yields. We developed and tested a prototype CatTrap and showed that the idea of trapping arboreal caterpillars is sound. The first design however was difficult to work with. We made a significant redesign that is much easier. We could not test this design due to COVID. 3) The goal of the semi-arid habitat is to determine the economic feasibility of growing fields of host plants to grow harvests of Hyles lineata caterpillars. We established a field plot of eight species of H. lineata host plants. We did not follow through with this part of the project partly due to COVID and partly due to the dramatic decrease in insect abundance that has occurred worldwide. The abundance of H. lineata in AZ dropped by 90% which was too few to do anything meaningful. 4) The goal of the grassland habitat is to test the feasibility of using grasslands to grow grasshoppers for food. This grant supported development of a mechanized grasshopper harvester through the College of Engineering Senior Capstone Design Day program. Three different teams of undergraduates designed, built and tested three iterations of the harvester. A total of 13 engineering students were supported by this grant on this project. We submitted a provisional patent (UA19-089, UNIA 19.07 PROV). This patent will be updated once this year's cohort has completed its redesign.
Publications
- Type:
Journal Articles
Status:
Other
Year Published:
2021
Citation:
The species-centric versus habitat-centric approach to insectsas food and feed. current opinion in Insect Science.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2021
Citation:
Substrate composition effect on growth of Cotinis mutabilis larvae: a case for detritivore scarabs in the insect agriculture industry. Journal of Insects as Food and Feed.
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