Project to Determine the Economic Viability of Black Soldier Fly Grubs as an Alternative Protein

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2009: $5,001.90
Projected End Date: 12/31/2011
Region: North Central
State: Iowa
Project Coordinator:
Mari Holthaus
Kymar Acres

Annual Reports


  • Agronomic: potatoes
  • Vegetables: beans, beets, broccoli, cabbages, carrots, cauliflower, cucurbits, eggplant, onions, peas (culinary), peppers, radishes (culinary), rutabagas, tomatoes, turnips, brussel sprouts
  • Additional Plants: herbs, ornamentals
  • Animals: poultry


  • Animal Production: feed/forage
  • Crop Production: organic fertilizers
  • Production Systems: organic agriculture, integrated crop and livestock systems

    Proposal summary:

    The profitability in egg production at the scale we operate is limited especially when utilizing hired labor. There are two options to remedy this problem; we can increase our prices or reduce our expenses. As we live in an area where a high percentage of the residents have low income the increase in price would limit those who could afford our eggs, which we believe are more nutritious and tastier. Not only would a price increase reduce the number of individuals who can afford our product, it would affect the number of local businesses that we could market to. We think that reducing the cost of production is the best way to improve our ability to profitably market our eggs in Northeast Iowa. We have reduced our cost of feed, to some extent, by providing pasture, however this is limited because of the seasons and we still need to purchase feed for substantially all of the needed protein. As protein is the most expensive part of the feed rations it would benefit our farm, and others with mid-sized flocks, to find a renewable source of protein.

    We would like to develop, and determine the viability, for the production of Black Soldier Fly grubs as a protein rich feed additive for our chicken flock. The idea was brought to my attention by an article in Backyard Poulty and after doing more research I have found that while the use of Black Soldier Fly grubs is not new it has not been developed in a commercially feasible way. There is a further problem for our area as the fly is not native and it will not naturally lay eggs in our material bins. After studying the problem we have developed a plan to overcome the problems in order to utilize the high protein food they provide.

    We plan to test a couple of elements pertaining to the production of the Black Soldier Fly grub. First we would like to determine the rate of grub production with different materials. A second goal is to find an efficient way to keep the population in production throughout the winter months. Finally we would like to find good uses on our farm for the by-products of the growing of the grubs.

    Kymar Acres would like to determine which type of material best produces the Black Soldier Fly grubs. This will be done by having three sets of testing containers with each set containing different materials. We will weigh out, and track the materials as they are added daily and the grubs as they are harvested. We will test the use of only chicken manure, only cattle manure, as well as a combination of chicken manure and food waste from our vegetable production in the summer and cow manure in the winter. We will have three containers in each set so that there will be production in some containers while another is being reset and cleaned out. This will also provide a method of getting a better rate of production by averaging the results. There has been research on the protein content of these grubs and we then can calculate, when we have weights, how much protein to take out of our feed rations and therefore the cost reduction in the feed. We will also look into which type of bin works better, a plastic one or one made out of plywood and lined with a protective material. With the information we gather we will be able to determine the cost savings of grub production.

    In order to maintain a consistent supply of the grubs we need to develop a way to cultivate the grubs the entire year. In order to do this we will create a screened area where the adults will not leave during the summer and where we can add insulation as the seasons cool. As the grubs grow and consume the materials the process produces heat and we will harness this to keep a temperature high enough. In order to keep a constant temperature, to facilitate grub production, we will vent the heat created by the chickens into the grub production area and vice versa as needed; this will eliminate the need for an artificial heat source. Thermometers will be used in each container to ensure the heat is evenly distributed. By keeping the area warm enough we will be able to keep an area where some of the grubs will be allowed to mature. The grubs will then burrow into the ground from where they will emerge as adults to mate and lay eggs again. Keeping the area warm enough will allow us to have a high protein food source all year as well as allowing us to keep the population numbers high enough.

    As the grubs consume the materials provided to them they create two main by-products. The process creates a large amount of moisture depending on the beginning materials, and it is supposedly much like a compost tea. The pH levels and the value as a fertilizer would have to be determined after the process has been completed. The second by-product is the remaining composted materials that the grubs did not consume. This product may be useful as a soil amendment or as a potting material in the greenhouse. The amounts of each by-product would need to be determined and will be tracked in each set of materials. If these by-products are shown to be useful they would be a good organic product to use in the production of vegetables, flowers and herbs. This could potentially create a revenue stream for those that have no use for the products or a consistent supply of material if they do.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.