Breeding Techniques and Management Methods for the Ground Beetle

The ground beetle, known by its medicinal name Su tubyuan, is a commonly used traditional Chinese medicinal material.

I. Living Habits

Both adults and nymphs prefer to live in dark, moist, humus-rich, slightly alkaline loose soil. During the day they retreat into shallow soil, and at night (or on overcast and rainy days) they come out to move about, forage, or mate. Adults have the habit of eating eggs, and when hungry they also cannibalize each other. Around the Beginning of Winter, as temperatures drop, they begin hibernation, overwintering dormant in soil 5 cm deep on sunny, wind-sheltered slopes, and emerge to forage after the Awakening of Insects the following year.

II. Reproduction

The ground beetle is an oviparous animal. After mating, the female begins laying eggs in about 7 days, and completes one full generation in 1.5 to 2 years. The peak egg-laying period is from June to September each year. Eggs are collected once every 15 days (passed through a 6-mesh sieve). At 30°C to 32°C and a rearing soil humidity of 20%, all eggs hatch in about 40 to 60 days. When nymphs grow to the 6th instar, remove excess males to achieve a female-to-male ratio of 3:1, and at the same time separate the young and mother ground beetles into different pools for rearing (passed through a 2-mesh sieve).

III. Construction of Rearing Pools

Rearing pools are suitable for larger-scale rearing of nymphs from the 5th instar onward and adults. The size depends on the number of ground beetles being reared. For egg incubation and small-scale rearing, rearing jars may be used. In a well-ventilated, cool location facing south with shade trees, dig a pit 1 m deep, 2 m long, and 1.5 m wide. After leveling and tamping the bottom, build brick walls 1 m above ground, smooth the inner surface with cement, and point the outer joints with cement. Install a lid on top of the pool with a movable door (the inner layer is 40-mesh iron gauze, with an outer wooden cover). At 15 cm from each end of the lid, embed ventilation holes covered with 40-mesh iron gauze. The joints between pool walls must be sealed. Spread 20 cm of rearing soil on the pool bottom, set up feeding and watering equipment, and then the insects can be introduced.

IV. Rearing Management

1. Feed The ground beetle is an omnivorous animal. Animal-based feeds include earthworms, crickets, mole crickets, and various animal by-products. Plant-based feeds include wheat bran, rice bran, oilseed cakes, starch residues, okara, corn, broken rice, and green vegetable leaves, cabbage leaves, pumpkin flowers, mulberry leaves, melon and fruit peels, etc.
2. Water supply In summer, place several small water basins in the rearing pool for the ground beetles to drink from, and frequently sprinkle water in the pool. During hibernation, prolonged dryness in the pool should also be avoided. When feeding semi-dry and semi-moist feed, the pool should be kept moist in spring and autumn (rearing soil humidity 20%).
3. Rearing soil In winter, select humus-rich, loose, and fertile garbage mud, garden soil, ditch mud, stove-foot soil, sandy soil, loam, etc., mix in 20% to 30% chicken manure, pig manure, burnt mud ash, or plant ash, and sun-dry it in the sunlight. The depth of rearing soil in the pool: 7 cm to 10 cm for the 1st to 4th instars, 16 cm to 20 cm for the 5th to 8th instars, and 20 cm to 26 cm for nymphs from the 9th instar onward and adults.
4. Temperature and humidity The suitable environmental temperature for ground beetle growth is 25°C to 30°C. They begin to move and forage above 10°C, burrow into the soil to hibernate below 10°C, and die at -5°C. Therefore, in winter, place some rice straw, chicken feathers, and other warming materials in the pool, and remove them promptly at the next year's foraging period. The relative humidity should preferably be 75% to 80%.
5. Strictly prevent poisoning Within 100 m around the pool, it is strictly forbidden to place or use pesticides, chemical fertilizers, etc.
6. Timely separation of young and mother ground beetles During the rearing process, mother ground beetles often eat larvae and eggs. Therefore, once the larvae can move and forage on their own (referring to nymphs from the 5th instar onward), the mother ground beetles should promptly be moved to another pool, and at the same time the larvae should also be reared in separate grades.
7. Rearing density Per square meter, 1.5 kg of adults can be reared, 0.15 kg to 0.5 kg of 1st to 3rd instar nymphs, 0.6 kg to 1.2 kg of 4th to 6th instar nymphs, and 0.6 kg to 0.9 kg of nymphs from the 6th instar onward.
8. Properly feeding young nymphs This mainly refers to nymphs from the 1st to 4th instars, which are small and weak, so concentrated feed should be the main feed. The feed can be evenly scattered on the surface of the rearing soil, then use your hand to rake about 2 cm deep into the central soil so that the feed is mixed into the surface layer, and take care to prevent escape.
9. Prevention of insect pests and natural enemies
(1) Ants: Dig a trench around the pool and fill it with water, or apply tung oil, sticky substances, etc., on the pool walls.
(2) Mites: First, use roasted concentrated feed to attract and remove mites during the day; second, replace the rearing soil; third, chemical control, that is, for each cubic meter of soil, use 5 g of trichlorfon, 50 g of quicklime, 50 g of chimney ash, and 2.5 L of hot water. After dissolving, filtering, and removing residue, spray evenly onto the rearing soil from which the insects have been sifted out, once daily for 5 consecutive days.
(3) Rats, cats, weasels, chickens, ducks, frogs, snakes, spiders, etc., are all natural enemies of the ground beetle. Measures such as adding iron gauze covers and sealing should be taken for prevention.

10. Disease prevention and control

(1) Big belly disease: Diseased insects have swollen and shiny abdomens, pointed heads, and loose feces. Prevention and control measures: Keep soil moisture during the larval stage below 10%, alternate dry and moist feed, and during the mid-instar and adult stages also regulate soil moisture properly according to growth needs.