Canadian goldenrod, alligator eel, Fushou snail, water hyacinth and other organisms have repeatedly appeared in the news, and invasive alien species have increasingly become the focus of people's attention. With the continuous development of the mainland's foreign economic cooperation and trade, the emergence of emerging industries, and the interception of foreign pests at border ports across the country have also shown the characteristics of increasing the number of types of batches, expanding the scope of spread and intensifying the harm, seriously threatening the ecological environment, agricultural and forestry production and human health of the mainland. At present, more than 670 invasive alien species have been discovered on the mainland, making it one of the countries in the world most affected by invasive alien species.
The report of the 20th National Congress of the Communist Party of China pointed out that it is necessary to improve the diversity, stability and sustainability of ecosystems and prevent the encroachment of alien species. In recent years, the mainland has also successively issued a series of laws and regulations to prevent and manage the invasion of alien species, strengthening the important position of preventing the invasion of alien species in the national biosecurity governance system. Fuso mealybug was listed as a national agricultural and forestry quarantine pest in 2010 because of its many host plants, small insect body, hidden hazards and strong drug resistance.
What is a fuso mealybug?
Phenacoccus solenopsis Tinsley, a genus of homoptera, mealybugs, and mealybugs, is an alien pest that has invaded the continent, mainly harming gardens, fruits, and a variety of important cash crops in the field. Native to North America, the worm was found to harm cotton in the United States in 1991 and subsequently reported in Mexico, Chile, Argentina and Brazil. Following the discovery of an outbreak of the worm on cotton in India and Pakistan in 2005, which caused extremely serious damage to the local cotton farming industry, mainland researchers detected the damage in Guangzhou in August 2008 and confirmed that the worm has a high risk to Chinese cash crops.
Eggs, larvae, pupae and adults of the Fuso mealybug (picture from the Internet)
The Fuso mealybug completes a generation through five worm states: egg, nymph, prepupae, pupae and adult. Adults and nymphs are oval in shape, usually pale yellow to orange-yellow in living bodies, with a series of black spots on the back, tiny bristles distributed throughout the dorsal surface, and a white waxy discharge covering the body surface. Its life cycle is 23-30 days. Fusang mealybug camp parthenogenesis, strong fertility, female adults can lay 500-600 eggs, 10-15 generations can occur per year, the eggs are round, light yellow color. According to the survey, the cotton yield after being infested by the Fuso mealybug mealybug has decreased by more than 40%, and some fields may not be harvested. After the cotton is harvested and left the field, mealybugs are transferred to other hosts in the field. Mealybugs overwinter in soil, crop roots, stems, bark crevices, and weeds as young nymphs or eggs, short distances through airflow, but also with the help of water, bed soil, humans, domestic animals and wildlife.
How harmful is the Fuso mealybug?
The mealybug is a polyvorous insect, and the cotton plant is its best host, and the whole growth period of cotton is infestation by mealybugs, and the generations overlap, and the insect states coexist. The harmful characteristics of cotton are as follows: one is to suck the sap of cotton roots and leaves with the mouth needles of larvae and adults, so that the plant grows short, the cotton peach falls off prematurely, and the cotton leaves fall off completely in severe cases, and the other is the accumulation of white waxy substances on the cotton mealybug inferior parts such as the top of the cotton plant and the stem. Third, the honeydew excreted by the fuso mealybug lures the vigorous activity of ants, resulting in the breeding of black mold in the harmful parts of cotton, affecting cotton photosynthesis and inhibiting growth. Fourth, mealybugs are easy to transfer and spread, and spread through a variety of ways, so that they can quickly spread to new areas and continuously expand the scope of harm. Fifth, high temperature and low humidity are conducive to the rapid reproduction of Fuso mealybug and increase the degree of harm.
The harm of fuso mealybug to cotton (picture from the Internet)
How to control the fuso mealybug?
Young mealybugs have high mobility and can crawl long distances. Adult worms have powdery waxy coverings, and the liquid is not easy to enter the body directly, and the drug resistance is strong; Mealybugs are sticky and can attach to farm implements, animals, cotton farmers, and ordinary people, and spread with their movement. Due to the above characteristics, prevention should be adopted in the prevention and control, comprehensive control policy, to eliminate mealybugs in the initial invasion stage. Therefore, the control of Fuso mealybug is carried out in the following ways: (1) Strict quarantine: It is strictly forbidden to transfer seedlings with Fuso mealybug to areas where it has not occurred. (2) Investigation and monitoring: Carry out investigation and monitoring in areas that have not occurred, and report and kill them in time once found. (3) Chemical control: the occurrence area can be controlled with propylbromophos, thiazidone, chlorpyrifos, imidacloprid, thiamethoxam, chlorpyrifos and other agents. (4) Biological control: The use of natural enemies (especially parasitic wasps) is considered to be the key means of natural control of Fuso mealybugs.
Staff conduct survey and monitoring in cotton fields (picture from the Internet)
Parasitic bee control (picture from the Internet)
At present, the cotton planting area in the mainland has reached more than 3,000 thousand hectares. Fuso cotton mealybug can be carried by means of transportation and trade materials for long-distance transmission, especially the illegal transportation of flowers and seedlings, once introduced into cotton area colonization, will pose a serious threat to the mainland cotton industry, directly affect the stability and coordinated development of the national economy, so the prevention and control of Fuso cotton mealybug to protect the safety of mainland cotton production areas can not be delayed!
Author: TANG Zhenzhen (Graduate student, College of Life Sciences, Hubei University)
Scientific checkpoint: Xu Lotian (Associate Professor, Hubei University)
Source: Guangming Network - Popular Science China