Introduction to a Simple Method for Outdoor Culture of Fly Larvae

    Although outdoor fly larvae culture yields less than three-dimensional fly larvae culture and is not as stable, it has the advantages of low investment, quick results, no need for seed stock, no need to feed the flies, and low cost, making it the choice of most farmers today.

The suitable season for simple outdoor fly larvae culture is generally from late April to mid-October each year.

Construction of the simple culture house

The site should be chosen far from living areas, in a place with tree shade but certain light, and with relatively many wild flies. The area should be determined according to the required output; based on production experience, the average yield is about 0.5 kg per sq m. The culture house only needs to be rainproof; a thatched hut, cement tile house, or bark house will all do. The house must be enclosed with 1 m high screen windows to prevent chickens, ducks, and other animals from entering. The culture ponds should be simple cement ponds, each with an area of 1.5 sq m to 2 sq m, and the pond edge should be 20 cm high.

Preparation and arrangement of the manure material

70% fresh pig manure (from pigs within 3 days of defecation), 30% chicken manure (within one week); 100% fresh pig manure from slaughterhouses; 75% pig manure, 25% tofu residue; 50% chicken manure, 25% pig manure, 25% tofu residue. Mix the above manure materials, with a moisture content of 100%, pile the manure to a height of 20 cm, cover tightly with agricultural film, and it can be used after 24 hours to 48 hours. Since this is outdoor culture, the manure material can also be used without fermentation and put directly into the culture ponds. Put the fermented manure material into the larvae house, piling three strips in each pond, each strip 0.8 m long, 0.2 m wide, and 0.15 m high. The time for adding manure is from 4 pm to 5 pm every day.

Preparation and arrangement of the egg-collecting material

Because this is outdoors, there are more choices for the egg-collecting material. Dead fish and the like can be placed directly on the manure pile, or it can be prepared according to the following formula: based on 100 kg of manure material: 1 kg wheat bran, 2 liang fish meal, 3 liang peanut bran, 1.5 kg water. After mixing evenly, it can be placed on the manure pile. After placing the egg-collecting material, avoid walking around the edge of the larvae pond.

After the manure material is placed and the egg-collecting material (for the first few days, dead fish or fish internal organs are best, to attract wild flies) is put on, in places with relatively many wild flies, generally within half an hour a large number of flies gather on the egg-collecting material to lay eggs. At 9 pm, use a small amount of egg-collecting material to cover the fly egg clusters with a thin layer, to increase the hatching rate and reduce harm from ants and other insects. The fly egg clusters will all hatch by the next morning. After 36 hours to 48 hours, the fly larvae have already crawled the previously divided manure piles into a scattered mess. At 72 hours, the growing fly larvae begin to crawl out of the manure piles and automatically disperse into the larvae-collecting bucket. Generally by the seventh day, all the fly larvae in the manure material have dispersed cleanly.

Assume your larvae ponds total 14. You should add manure to two ponds each day, and all will be full by the seventh day. On the eighth day, shovel out the residual manure from the first day after the fly larvae have all emerged, and put in new manure material again. Production cycles in this way.

At 10 am, collect the fly larvae from the larvae-collecting bucket, shovel out the residual manure from which the fly larvae have all emerged, and shovel the manure in other ponds that has been scattered by the fly larvae and has piled up at the pond edges onto the middle of the manure piles, so as to avoid blockage and prevent the fly larvae from being unable to distinguish the route when dispersing.

Simple outdoor fly larvae culture does not require feeding. But in order to keep the flies staying around the larvae culture house and unwilling to leave, new manure material and egg-collecting material must be placed every day. The food of the flies mainly comes from the manure material and egg-collecting material.

Because outdoor fly larvae cannot be disinfected, the fly larvae cultured in this way certainly carry many harmful bacteria. Before use, it is recommended to soak them in 7 ten-thousandths potassium permanganate water for 5 minutes before feeding them to economic animals.