A detailed guide to new farming techniques for ground beetles: master scientific breeding methods

  Make rational use of space when building breeding pools. To make use of limited space, flat pools should be improved into multi-tier pools. Leave a 60cm-wide walkway in the middle, and build pools on both sides with brick and cement board structures. Each tier is 40-45cm high, the pool depth is 20-25cm, and glass strips (smooth, to prevent escape) are pasted along the edges, with 8 tiers in height. The breeding area per room increases from less than 20 sq m previously to 120 sq m now. 

Mix the rearing soil according to their habits. Ground beetles like to live under soft, moist soil. The best soil mix is 70% odorless sawdust from poplar, willow, or paulownia trees, 28% fertile soil rich in humus from vegetable fields (or old wall soil), and 2% plant ash or cow dung. Mix and pass through a No. 4 sieve, spray with water to moisten, pile up and ferment for 10 days before use; the longer the time, the better. When using, spray with 0.2% salt water. The moisture level should be such that it forms a ball when squeezed by hand and crumbles when dropped. Place it in the pool at a thickness of 15cm. 

Get the stocking density right. At different instars, the appropriate density must be maintained. If the stocking density is too high, growth and development will be uneven; if too low, the soil mix easily becomes compacted. The optimal density is 200,000 larvae per sq m, 120,000 per sq m when they are mung-bean sized, 25,000-30,000 per sq m when they are broad-bean sized, no more than 10,000 per sq m for adults, and at most 4,000 per sq m for egg-laying insects. 

Feed must be nutritionally complete. Ground beetles are omnivorous insects, and their feeding trait is a preference for fresh food. They most like eating wheat bran and rice bran, followed by cornmeal, crushed mixed grains, peanut cake, soybean meal, mixed fish, meat, and various green grasses, vegetable leaves, melon and fruit peels, chicken manure, cow dung, and other coarse materials. If fed only forage such as green grass, they grow slowly. A complete feed can use 72% wheat bran, 20% cornmeal, 5% soybean cake, and 3% animal feed (fed cooked). When feeding, scald it with boiling water and add 30%-40% green vegetables or melon and fruit types. When reared on complete feed for 5-6 months, individuals can grow into adults. 

Feed at the right time. Ground beetles are insects that hide by day and come out at night, beginning activity 2 hours after dusk each day. The daily feed should be given completely at dusk, with the concentrated feed eaten the same day, and the green feed the next morning. Clean up the next day. Do not let green feed rot in the pool to prevent disease.  Control temperature and humidity. Humidity differs little among the instars of ground beetles. The nymph stage is better slightly drier, but not below 40%; the adult stage is better slightly moister, but not above 90%. Temperature is an important condition for the growth of ground beetles. From minus 2°C to 10°C they will be frozen stiff, and above 45°C they begin to die. To prevent heatstroke or increase humidity, water can be sprayed on the surface, but it must not be too wet. When humidity is high, attention should be paid to ventilation. In winter, the thickness of the soil mix should be appropriately increased, and a stove can be lit in the middle of the rearing room, but the smoke must be discharged outdoors. In a single-room multi-tier rearing setup, the temperature can reach about 30°C, the ground beetles grow normally, and the yield is the same as in summer. 

Sieve the insects at the right time. When the temperature is suitable and feed is sufficient, ground beetles grow into adults in 5.5 months and should be sieved out promptly, dried, and sold.