Citrus is a subtropical perennial evergreen fruit tree, a subordinate plant of the family Rubiaceae, and one of the main fruit tree varieties currently cultivated in China. Because of the unique taste of citrus, its sweet and sour taste is loved by people, and over time, citrus has naturally become one of the common fruits on the market.
In addition, the main origin of citrus is in China's Yunnan-Guizhou Plateau. It prefers a warm and humid climate, and is mainly distributed in areas around 20° to 33° north latitude according to latitude. According to relevant records, after the 1990s, China's citrus cultivation area has reached more than 1 million square hectares.
Now, it's autumn and winter, and it's a good time to pick and sell citrus. However, in the middle of the process, many fruit farmers may have a headache, because there are many insect pests that occur on citrus trees, and there are more than 50 to 60 species of citrus pests that can harm citrus in China alone, and the emergence of these pests has seriously affected the production and sales of citrus and brought great economic losses.
Today, we will talk about a pest that is very common in citrus at present- the orange small fruit fly. Look at the specific situation of this pest, grasp the physiological habits of this pest, and do the corresponding preventive measures before it occurs, or it is better to be able to respond in time when the orange small fruit fly breaks out in a large area.
<h1>Taxonomic status and distribution of the orange-sized fruit fly</h1>
The orange-sized fruit fly is an insect in the subfamily Oligosperifidae of the family Diptera, whose Latin scientific name is Bactrocera dorsalis Hendel. Orange small fruit fly in China is listed as a quarantine object at home and abroad.
Orange small fruit fly is native to Kyushu, Japan, Taiwan and other regions of China, but the current distribution range has been greatly increased. For example, the Philippines, Pakistan, India, Indonesia, the United States, Australia (Australia has reportedly eradicated the orange fruit fly) and about 20 other countries are also distributed.
In China, orange small fruit fly is mainly distributed in Taiwan, Guangdong, Guangxi, Sichuan, Chongqing, Hubei, Fujian, Jiangxi and other provinces.
From the distribution status and growth habits of the orange fruit fly, the area south of north latitude 25O is the most suitable for the survival and growth of the orange small fruit fly.
<h1>Morphological characteristics of the orange fruit fly</h1>
From the perspective of the old mature larvae, the average body length of the orange small fruit fly is 10.0 to 11.0 mm, the appearance is yellow-white, the larvae as a whole are maggots, and the anterior part is small and pointed, but the posterior part is the opposite wide and round, and the color of the seven-mouth groove is black.
From the adult point of view, the body length of the orange small fruit fly is about 6-8 mm, and there will be two large black spots nearly round on its shape. The dorsal plate of the middle chest of the orange fruit fly is black, and there will be a slightly wider longitudinal band on both sides of the insect body, this longitudinal band is yellow, and the shoulder blades, dorsal blades and small shields of the living orange small fruit fly are yellow, which is also one of the main identification characteristics of the orange small fruit fly. However, after the death of the insect body, the shoulder blades, dorsal blades, and small shields that were originally yellow will become dark yellow.
The small shield of the orange fly has a pair of manes, which is one of the main features. In addition, it has 2 pairs of dorsal manes, 2 pairs of shoulder manes, 1 pair of mid-sided manes, 2 pairs of hindwing upper manes, and 1 pair of forewing upper manes. One thing to note is that there are no wing top spots on the wings of the orange fly, which is also one of the main characteristics of the orange fly.
In addition to the above characteristics, the orange fruit fly also has a major feature, that is, the orange small fruit fly has a dark horizontal band on the leading edge of the dorsal plate of the 3rd abdominal segment, and the 3rd to 5th segment has a narrow black longitudinal band, which constitutes a "T" shaped black spot.
Because several fruit flies of the fruit fly family are more similar in appearance, such as orange fruit fly, melon fruit fly, Mediterranean fruit fly, etc. are relatively close to the appearance of orange small fruit fly, so only by mastering the above main characteristics can we clearly distinguish whether it is an orange small fruit fly.
<h1>Pest characteristics of the orange small fruit fly</h1>
Orange small fruit fly mainly has the following two pest characteristics.
The host range is large and extensive.
Orange fruit fly will mainly harm citrus, banana, mango, peach, guava, fig and other fruit trees, but can also harm peppers, red tomatoes, loofah, bitter melon and other vegetables, according to relevant surveys found that the orange fruit fly can harm a total of 46 families of a variety of fruit trees, flowers and vegetables, it can be seen that its wide range of harm and the variety of hosts.
The hazards are heavy.
The damage caused by the orange fruit fly is very serious, and it can be said to be a devastating pest on vegetables, fruit trees and flowers. Why is the orange fly so described? The main thing to start with is the way it is harmful. Adults of the orange fruit fly lay their eggs mainly under the skin of the host. After these egg blocks hatch into larvae, the larvae will dive into the host, causing harm such as fruit fall or fruit rot to the host, bringing great economic losses, in China, orange small fruit fly can cause more than 2 billion economic losses per year.
<h1>Biological characteristics of the orange fruit fly</h1>
Orange fruit fly in China can occur 3-9 generations a year, in China's South China, orange fruit fly is not a strict overwintering phenomenon. In other areas , the orange fly overwinters in the form of a pupa in the form of a wet and loose topsoil , or in the form of an adult overwintering in the weeds.
In Guangdong region, the number and number of orange fruit flies occur the most in July and August, and in August to September, it is the adult peak of orange small fruit flies, but the adult peak of different regions is also different.
It has been observed that orange flies can generally produce a generation in about 28-35 days.
In addition, adults of orange flies have a habit of absorbing honeydew and nectar in the cool morning. After feathering, the orange fruit fly will reach sexual maturity at 11 to 13 days, and after sexual maturity, the adult worms are extremely strong in methyl eugenol, which provides ideas and methods for the control of orange small fruit fly.
Orange flies like to lay eggs under the peel, and after laying eggs, the surface of the peel will leave a certain spawning mark - an egg-laying hole the size of a needle tip, after which this piece will slowly appear discolored and fluid.
<h1>Control methods of orange small fruit fly</h1>
There are certain principles to be observed in the prevention and control of orange small fruit flies: First of all, we must strengthen the monitoring and monitoring of orange small fruit flies, so as to achieve unified prevention and control, joint prevention and joint management, and in the process of prevention and control, we must implement regional prevention and control methods that are responsible to people (unified command, unified monitoring and reporting, unified drug supply, unified drug application).
In terms of prevention and control strategies, it is mainly necessary to use agricultural control as the basic method, and then combine it with physical control and chemical control to achieve the purpose of killing insects and preserving fruits. Among them, the comprehensive prevention and control methods applied with sexual attractants and food attractants have a very good effect. (This method is a treatment method derived from the above-mentioned characteristics of adult insects with strong tendency to methyl eugenol.) ）
In the comprehensive control, the first is to strengthen the monitoring and management of the insect situation of the orange small fruit fly and reduce the source of insects. The following methods can be taken:
It is necessary to strengthen the supervision and management of citrus trading venues, and the ground of trading venues should be hardened, otherwise it is easy to build cars and cause harm again. In the production site, it is necessary to establish its waste fruit treatment pond, and put the waste fruit into the treatment pool in time to carry out insect treatment. (Waste fruit can be found according to the morphology of the fruit laid by the adult insects described above.) ）
It is necessary to strengthen the scientific education of orange small fruit flies, and when maggot-like larvaes are found on fruit trees, it is necessary to do a good job of pest control in a timely manner, and it is strictly forbidden to throw fruits with larvae into public places or places closely related to agriculture, so as to avoid more serious harm in the coming year. Because the orange fruit fly is still a quarantine pest in some provinces in China, for these provinces, it is necessary to strengthen the quarantine measures for the orange small fruit fly to avoid the flooding of orange small fruit fly here and bring huge economic harm.
In agricultural prevention and control, it is necessary to do a good job of orchard cleaning in a timely manner. Especially in the affected orchards, during the fruit fall, the fallen fruit, insect fruit and rotten fruit should be removed in time to avoid the recurrence of insect conditions. Generally, in the early stage of fruit fall, the number of cleaning is once every 3 days, and in the peak period of fruit fall, it is necessary to clean the orchard more diligently and clean once a day. For the green fruits and overripe fruits in the orchard, they should be removed in time. These fruits can be deep burial, water immersion, plastic bag sealing fumigation, incineration and other methods of treatment, each treatment method has certain standards, such as deep burial should be buried in the soil layer below 50 cm, water immersion should be soaked for more than 8 days, in addition, these waste fruits can also be poured into the fertilizer pool for long-term soaking, or with 7500 times 50% fly killing amine wettable powder liquid soaked for 2 days.
In addition to cleaning up the orchards in time, agricultural prevention and control should also do a good job in winter ploughing and pupae. Before freezing in winter, the dead branches, fallen leaves and fallen fruits in the orchard should be removed and taken out of the garden for centralized burning. After cleaning, it is necessary to shallowly turn the garden soil 7 to 10 cm, which is to change the position of the pupa in the soil layer, so that these pupae cannot hatch normally because they are not adapted to the environment, and thus die.
In addition, bait monitoring and booby traps can be used to control orange small fruit flies. Sexual attractants can be trap ether, and traps can be used commercial traps or homemade traps. If you make your own home, the materials used are also very cheap, and you only need to make cylindrical plastic containers such as discarded mineral water bottles and beverage bottles. The production method is to drill two small holes in the middle and upper part of the mineral water bottle with a height of 1cm and a width of 2cm, and then use the wire to pass through the cap of the bottle to make a wire hook, and the length of the wire hook is about 1/3 to 1/2 of the bottle. Then put the poison bait on the hook. The bait can be made with homemade brown sugar bait, using 90% dichlorvos 1000 times liquid mixed with 3% brown sugar, in addition, there are other recipes, which are not listed here.
The use of fruit bagging can also control orange small fruit flies, and this method is the safest anti-insect and fruit preservation measure. According to the habit of orange small fruit fly to lay eggs on the fruit that begins to expand and soften, the corresponding bagging measures have been formulated, that is, bagging must be carried out before the orange fruit fly lays eggs, and another point should be noted that before bagging, the orchard should be comprehensively controlled by diseases and insect pests.
Of course, chemical control is also essential for orchards where orange flies are severe. When using chemical control, the best period for insecticide is during the peak of adult feathering and spawning, preferably from 9:00 to 10:00 in the morning, because during this time, the adults of orange fruit flies are more active. The application method can be selected from strip application or spot spraying, molasses can be added to the agent when spraying, and the agent is applied to the dense canopy, and the spray should be sprayed more than 2 times. It is best to use high-efficiency, low-toxicity, low-residue organophosphorus and permethrin agents, such as 10% cypermethrin 2000 times liquid, 80% dichlorvos 1000-2000 times liquid or 50% borage pine.
The above is the introduction and control methods of orange small fruit fly, you can choose the appropriate control method for prevention and control according to your own specific situation.