The scientific name *Ampullaria gigas* (Spix) refers to a large aquatic snail, also known by various synonyms such as *Ampullarium crosseana*, *Pomaceacineata*, *Pomacea canaliculata*, and *A. insularus*. This species is commonly found in provinces like Guangdong, Guangxi, Fujian, Hainan, and Taiwan, where it thrives in freshwater environments.
This snail primarily feeds on aquatic plants such as rice, water chestnuts, water spinach, and white peony roots, as well as crops near water bodies like sweet potatoes. It has become a serious pest, particularly after the transplanting of rice, when it damages the main stems and tillers, leading to reduced panicle numbers and lower yields. The snails are especially destructive during the early growth stages of rice.
In terms of morphology, the shell of *Ampullaria gigas* resembles that of other snails, with a spiral shape and varying colors depending on age and environment. The shell is often shiny with fine vertical stripes, and the snail has two pairs of antennae, with the posterior one being longer and having an eye at its base. A thick lung tube is located on the left side of the shell. Young shells are thin, while adult shells are thick, reaching up to 7 cm in height. The shell's umbilicus is deep and wide, and the snails are hermaphroditic, mating with each other.
The eggs are oval, about 2 mm in diameter, initially pink or bright red, and covered with a faint white powder. They hatch into young snails after about 5 days under warm conditions (May-June). Eggs are laid on dry surfaces above water, such as stems, walls, or weeds, and hatchlings fall into the water to feed on plankton. The snails mature in 3 to 4 months and live year-round in fresh water, except during droughts, when they seal their shells and remain dormant for up to 3–4 months.
In terms of life habits, this species has three generations per year in Guangzhou. The first generation takes 93 days to mature and start laying eggs, while the second generation requires 102 days. Under favorable conditions—average temperature of 27.1°C and humidity of 88%—the second generation matures in 63 days. The third generation takes 74 days, with an average temperature of 29.5°C. By the following March, the third generation is still young, with an average temperature of 18.2°C. Snails typically live between 20 to 80 days, and their weight increases over generations. The hatching rate is around 70.1%, with females producing an average of 3,050 offspring per generation. The second generation produces up to 1,068 young snails per female, showing strong reproductive potential.
For control, if there are 2–3 snails per square meter in rice fields, immediate action is needed. One method involves applying 6% Methyl Parathion granules (0.5–0.7 kg per 667 m²) in the evening or during rain, mixed with 5–10 kg of fine sand, and keeping a 3–4 cm water layer for 3–5 days. Another option is using 2% Tributyl Tin Acetate (TPTA) granules at 15–22.5 kg per hectare, applied 7 days before planting, with a 3 cm water depth for a week. If the water temperature is below 20°C, the dose can be increased but not beyond 22.5 kg. Alternatively, 80% Metaldehyde wettable powder (1.2 kg per hectare) can be used 1–3 days before planting, with a 1–3 cm water layer maintained for 7 days. Lastly, 8% Chlorhexidine granules (1.5–2 kg per 667 m²) can be applied in the evening, mixed with soil or crumbs, and the snails will die within 2–3 days after exposure. The best time for treatment is before egg-laying begins.
Whole Chest Oscillating Expectoration Machine
Whole Chest Oscillating Expectoration Machine,Chest Expectoration Machine,Expectoration Machine,Oscillating Expectoration Machine
JIANGSU JIANLAIBANG MEDICAL EOUIPMENT CO.,LTD , https://www.jsjlbmed.com