The town's Dabukou citrus orchard was built in the autumn of 2008, and when it was established, it mainly planted Navel orange varieties such as Qingjia and Newhall. In the spring of 2014, a high change was carried out, and the main varieties were Unknown Fire, Kiyomi, and Ehime 38. In 2016, the explosive skin insects became an outbreak of pests, the damage rate of citrus fruit trees reached more than 50%, and the individual plots reached 90%o larvae moths infested the main trunk or large branches, forming many insect channels under the skin, and the bark of the victims often burst in its entirety. After the tree body is damaged, the transport of water and nutrients is blocked, the branch extraction is reduced, and the amount of branches and leaves is small, resulting in the weakening of the tree, and the large branches or the whole plant die in serious harm.
< h1 class="pgc-h-arrow-right" > cause of the outbreak</h1>
In the past, Linshui County citrus poppers only occurred sporadically, the harm was not serious, it was a secondary pest of citrus orchards, basically no control measures were taken, and the economic loss was small below the level of pest allowability. In recent years, due to the large number of young and middle-aged laborers going out to work, the lack of rural labor, the comparative benefits of citrus production have been reduced, the management of orchards has been extensive, and the occurrence of diseases and insect pests has been relatively serious, especially the occurrence of popcorns has a general trend, becoming one of the main pests of some citrus orchards. Dabukou Orchard has not been established for a long time, and its citrus poppers are infested, mainly due to the following aspects.
1.1 Orchard management is extensive
Soil compaction, poor soil ventilation, lack of organic matter, overgrowth; insufficient fertilizer application, especially the application of organic fertilizer is seriously insufficient, resulting in weak tree potential and reduced insect resistance.
1.2 Poor drainage of orchards
Dabukou orchard terrain is relatively flat, good water conditions, before the establishment of the paddy field, high groundwater level, poor soil permeability, poor root growth and development, coupled with the orchard air humidity, is conducive to the growth and development of skin bursters.
1.3 Rootstock selection
Linshui County bursting skin insects occur serious orchards, its rootstock are fast growing, the formation of the canopy early, early results, yield performance and fruit quality of excellent citrus orange rootstock, compared with the use of citrus shells, orange rootstock navel orange orchards, popcorn insects are more harmful.
1.4 Winter clearance is not complete
The weeds, dead branches, fallen leaves and rotten fruits in the orchard were not cleaned up and destroyed in time; the bark of the old trunk was not scraped in time, the cracks in the trunk could not be filled in, and the trunk could not be kept smooth; the trunk was not completely whitened as required, providing a favorable environment for the overwintering, laying eggs and hatching of the skin bursters.
<h1 class= "pgc-h-arrow-right" >2 morphological characteristics of the popper</h1>
2.1 Adults
Body length 7 to 9 mm, black, with a metallic sheen. The female has a golden yellow head, and the male has an emerald green head, black compound eyes, and serrated antennae. The dorsal plate of the forebreast is equal to the width of the head, and the upper part is densely covered with fine wrinkles; the wing sheath is densely covered with small dots.
2.2 eggs
Flat, oval, milky white at first birth, orange-yellow later.
2.3 Larvae
The old mature larvae are 16 to 21 mm long, flattened, with dark brown mouthparts, small, brown heads, wrinkled body surfaces, and milky white breasts. The forebreast is particularly enlarged , with a distinct longitudinal stripe on the dorsal and ventral center ; the middle thorax is the smallest , and the thorax is degenerate. There are 9 segments in the abdomen, the posterior margin of each segment is wider than the anterior margin, the first 8 segments have 1 pair of stomata, and the caudal end of the terminal segment has 1 pair of black-brown tail forks.
2.4 Pupae
Flat-conical, milky white at the first pupal stage, soft and pleated, then yellow, and finally blue-black, with a metallic luster.
< h1 class= "pgc-h-arrow-right" >3 occurrence law</h1>
Generally, 1 generation occurs a year, with larvae of each age overwintering under the trunk bark layer (young age) or xylem (old mature larvae), pupal pupae begin in mid-March, pupate in mid-April, adults have suspended death, late April to early May is the first adult feathering peak, early to mid-May is the peak period of burrowing, and begin to lay eggs, early and mid-June is the peak of spawning, and late burrowing adults are at the end of June and mid-August, respectively. After hatching, the larvae first moth into the cortex, moth in the shallow part of the bark, oily brown transparent colloid flow out of the victim, and then gradually moth into the xylem, most of the moth into the xylem from September to October, down or upward moth to form an irregular moth, full of insect dung, so that the bark and the wood part are separated, the bark is dried and burst, and there is obvious sawdust accumulation on the ground where the victim is affected. After the larva matures, it burrows into a depth of about 5 mm in the xylem, and the moth overwinters into a crescent-shaped pupae, and the larval stage is generally 10 months.
<H1 class="pgc-h-arrow-right" >4 integrated control techniques</h1>
4.1 Eliminate the source of overwintering insects
Dead trees and dead branches, with a large number of larvae and pupae lurking in them, were thoroughly dug up and burned by early to mid-March.
4.2 The trunk is painted white
Scrape the bark of the old tree, fill the trunk cracks, worm holes, and keep the trunk smooth. Whitening of the trunk in early May before the adult spawns reduces spawning and avoids spawning.
4.3 Scraping, poisoning
When the hatching larvae are scraped and poisoned during the peak period of 6 to 8 months, pay attention to frequent inspection, and when foam or sap leaching is found on the trunk, scrape the subcutaneous larvae with a knife or cut 2 to 3 knives at intervals of 1 to 1.5 cm at the victim site, reach the xylem, and then apply 80% dichlorvos emulsion + Tobzin to kill the hatching larvae.
4.4 Adult insect feathering stage spraying
During the peak of adult feathering from late April to early to mid-May, terrin pesticides can be sprayed 2 to 3 times every 15 days.
4.5 Strengthen orchard management
Keep the tree tray clear and tillage, and control the height of weeds between rows to less than 20 cm. Balanced application of N, P, K and trace elements, and application of sufficient organic fertilizer to keep the tree growing strongly. Cut off foliage close to the ground, improve ventilation and light transmission, and reduce air humidity in the lower part of the canopy. 4.5.4 Reduce the groundwater level, poor drainage of the plot, timely cleaning of the drainage ditch, no drainage ditch and serious water accumulation, can dig a drainage ditch 60 cm deep and 50 cm wide, to ensure that the root system grows well, the branches and leaves grow strongly, the tree momentum is enhanced, and the resistance to insects is enhanced.