Small flower bug nymph.
This year, due to the higher average temperature in Beijing than in previous years, the precipitation is less, resulting in a high temperature and low humidity environment in the facility, which is conducive to the occurrence of small pests. Recently, the technical staff of the Beijing Plant Protection Station have continuously received calls for help from the plant protection departments of districts and counties and the technicians of some production parks, reflecting that the thrips in the production shed are rampant, and the harm is very serious. The survey found that it was the most harmful to crops such as eggplant, pepper, cucumber and watermelon, with up to 1760 insects in 100 eggplant plants and up to 27 worms per flower on the flowerware of pepper, cucumber and watermelon.
Thrips are harmful features
Thrips are small insects with a file suction mouthpiece. The whole reproductive stage of thrips is divided into three stages: eggs, nymphs and adults. Thrips use adults and nymphs to file to suck the sap of the young tissues (branches, leaves, flowers, fruits, etc.) of the plant, and the young leaves and shoots of the victims become hard and curl and wither, the plant grows slowly and the internodes shorten; the young fruits (such as eggplant, cucumber, watermelon, etc.) will harden after being killed, causing fruit fall in severe cases, which seriously affects the yield and quality.
The adult thrips are lively, good at flying and jumping, and can be spread by the wind. Thrips have a habit of tending to green and are afraid of light. During the day, it is generally concentrated on the back of the leaves, and can be active on the leaf surface on rainy days and evenings. Thrips generally reproduce parthenogenetically and occasionally both sexes. The suitable growth environment temperature of thrips varies according to different types, the most suitable development temperature is 24 °C -30 °C for melon thrips, 23 °C -26 °C for onion thrips, relative humidity is 40%-70%, if the temperature reaches more than 35 °C, the insect population is significantly reduced.
In recent years, the occurrence of thrips in melons, fruits, vegetables, and cotton has increased year by year, and has become one of the main pests, especially in vegetable crops such as nightshade fruits and melons cultivated in protected areas, there is a tendency for "small insects" to become major pests. Because the environmental conditions of protected area cultivation are conducive to the occurrence of thrips, and because of their rapid reproduction speed, if they are not prevented in time, they will cause catastrophic damage, seriously affecting the growth of plants and the quality of fruits. Therefore, we must pay attention to the prevention and control of thrips, so as not to make "small insects" into major pests.
At present, in the actual production of thrips or chemical pesticides, but the long-term uncontrolled, irregular use of chemical pesticides caused a series of ecological environment and food safety problems, 2010 Hainan "poison cowpea incident" is because some farmers use water amine thion and other highly toxic pesticides to control thrips caused. In order to promote the reduction of pesticides, the Beijing Plant Protection Station has continuously studied and introduced new biological control technologies and products, and at present, a new member has been added to the team of biological predators in Beijing - the East Asian small flower bug, and the commercialization of the East Asian small flower bug has been realized, providing new products and technical reserves for the production of vegetables in Beijing facilities.
The East Asian flower bug is a natural predator with great potential for exploitation
The East Asian small flower bug belongs to the order Hemiptera, The flower bug family, and the genus Small Flower Bug. The genus is the most diverse genus in the family Phylloscopidae, widely distributed around the world, and is an important natural enemy of insects such as Taenoptera, Homoptera, Lepidoptera, and leaf mites. In the 1980s, Canada successfully controlled the westflower thrips on cucumbers by introducing the American flower bug, and at present, many natural enemy companies in North America and Europe provide small flower bug products for the control of thrips.
East Asian small flower bugs are important predatory predators of various agricultural and forestry cash crop pests such as vegetables, fruit trees and cotton fields in northern China. Widely distributed, Beijing, Tianjin, Hebei, Shanxi, Hunan, Hubei and other places are distributed; the occurrence time is long, in the Beijing area from the end of April to the beginning of October; the predatory range is wide, and it has a strong predatory effect on pests such as thrips, aphids, leaf mites, whiteflies, leafhoppers, lepidoptera eggs and hatching larvae, and is a natural enemy with great potential for utilization.
After more than two years of research and development, the Municipal Plant Protection Station has mastered the biological characteristics of the East Asian small flower bug, developed the indoor large-scale breeding technology, established a pilot production line, and carried out experimental demonstration and application promotion in the field. In 2015, the Beijing Natural Enemy Insect Breeding Base has begun to breed East Asian small flower bugs on a large scale, with an annual breeding capacity of 30 million heads.
Application technology of thrips prevention and control of East Asian small flower bugs
■ The occurrence of thrips in the field is monitored by blue plate, and when the occurrence of thrips is detected and the population density is 1-2 heads/plant, the East Asian small flower bugs are released for prevention and control.
■ East Asian small flower bug control thrips application method: when the greenhouse prevention of pests, according to the number of 0.5 heads / square meter, released again after 14 days; when each plant of 1-2 thrips is monitored, released according to the density of 1-2 heads / square meter, released again after 7 days; when the pest occurs seriously, released according to the density of 10 heads / square meter. Unleashing the East Asian Flower Bug can be done using the Hanging Bag Method or the Scatter Cast Method. Hang the bagged product on the stem and petiole of the plant to avoid direct sunlight and rain into the bag, or sprinkle it directly on the leaves of the plant along with the culture medium, and do not irrigate for 2 days to facilitate the transfer of east Asian flower bugs scattered on the ground to the plant.
Demonstration and application of East Asian small flower bugs
In the first half of 2016, the Beijing Plant Protection Station, together with the Changping District Plant Protection Plant Inspection Station and the Shunyi District Plant Protection Plant Inspection Station, carried out the evaluation of the effect of thrips prevention and control of East Asian small flower bugs on a variety of crops such as eggplant, pepper, cucumber and watermelon, and the control effect of East Asian small flower bugs on eggplant reached more than 78% and the control effect on pepper, cucumber and watermelon flower utensils reached more than 70%. On the basis of obtaining good experimental results, a total of 11 bases in Changping District and Shunyi District carried out a demonstration of the control of thrips by natural enemy insects, east Asian small flower bugs. The area of the demonstration area is 200 mu, and a total of 100,000 East Asian small flower bugs have been released.
Beijing Plant Protection Station Sun Beibei Li Jinping