Rhododendron is a semi-evergreen shrub commonly used in gardens in recent years, it is not only lush foliage, but also more shade-tolerant, widely used, whether it is in the urban road greening, or in the community park can be seen in its figure. In addition, the hairy rhododendron has a bright and colorful flower when it blooms, so it is deeply loved in the garden.
The picture shows the rhododendrons blooming in the greenery
However, just a few days ago, a friend sent me a message saying that the leaves of the hairy cuckoo planted in their community have looked abnormal in recent times, and the leaves that should have been thick green are now basically showing a grayish-white color, and there are many small black-brown dot-like feces on the back of the leaves, hoping that I can find a solution for him.
<h1 class= "pgc-h-arrow-right" >why do the leaves of the cuckoo appear off-white? </h1>
The picture shows the off-white rhododendron leaves
The leaves of the cuckoo are grayish white mainly due to the infestation of the cuckoo reticulated bug, a sucking pest.
Rhododendron reticulated bug is a very common planter pest, mainly relying on its adult and nymphs gathered on the back of the leaves of the plant to suck the branches and leaves of the plant. Plants that are harmed by it usually have many yellow-white spots on the leaves at the beginning of the harm, and when the damage is more serious, these spots will be connected together, making the leaves lose green, thus showing the appearance of the entire leaf being gray-white.
< h1 class="pgc-h-arrow-right" > what are the effects on cuckoo cuckoo after the hazard of cuckoo reticulum bugs? </h1>
The picture shows the cuckoo reticulated bug on the back of the leaf
After being harmed by rhododendron reticulum, the leaves of the cuckoo will gradually lose green, their normal photosynthesis will also be affected, and the growth of the rhododendron will become weaker and weaker, and even the phenomenon of early leaf fall will occur.
The feces excreted by the rhododendron reticulum bugs on its leaves and molts are also easy to breed other bacteria on the leaves, making the back of the leaves of the rhododendron appear rusty yellow, affecting the normal growth of the rhododendron.
< h1 class="pgc-h-arrow-right" > what is the peak of the annual hazard of the rhododendron reticulated bug? </h1>
The picture shows the spots on the leaves of the rhododendron reticulated bugs after they are infested
The number of occurrences of cuckoo reticulated bugs in a year is very large, and in the northern regions, it can generally occur 4 to 5 generations a year, while in the southern regions, sometimes even 10 generations a year can occur.
Its annual hazard time can basically last from May to September, of which June to September is the most serious, and during this period, the degree of harm of cuckoo reticulo to cuckoo is often affected by weather conditions, and the more high temperature and drought weather, the more serious the hazard of cuckoo reticulated bugs.
<h1 class="pgc-h-arrow-right" > How to prevent and control the harm of rhododendron reticulated bugs to cuckoo cuckoo? </h1>
The picture shows the leaves of the cuckoo after the cuckoo reticulated bugs were harmed
(1) Reasonable clearance of the garden
After October of each year, the rhododendron reticulated bugs overwinter as adults under the leaves around the rhododendron, in the soil crevices or in the upturned skin of the plant, and then spawn on the back of the rhododendron leaves in April of the following year.
Therefore, in the early winter and early spring of each year, a comprehensive clearance of rhododendrons can be carried out to remove dead branches and leaves from the ground, and at the same time, the plants can be sprayed with insecticides for comprehensive prevention.
(2) Early spring roots are buried or sprinkled with drugs
After the soil thaws in mid-to-late March, combined with the watering of early spring water, part of the granular insecticides such as diazine phosphorus, octylthion, chlorpyrifos are applied to the roots of the rhododendron, and the drugs will be transported to the whole body of the plant with the absorption of the plant, so as to achieve the effect of stomach poisoning for pests.
(3) During the peak period of spawning, timely prevention and treatment.
April of each year is the peak spawning period of overwintering adults, and may is the peak of nymph hatching, during which if the rhododendron reticulated bugs can be controlled, it can be said that the annual control of rhododendron reticulated bugs is of great significance.
At this time, spirant ethyl ester or pyritoxe can be used for spray control, both of which have a good control effect on pest eggs and nymphs.
(4) Grasp the critical period and carry out prevention and control again.
Every year from mid-May to mid-June is the best control period for rhododendron reticulated bugs, because this period of high temperature and many areas are relatively arid, is the large number of breeding periods of rhododendron reticulated bugs, in this period of timely and effective control of rhododendron reticulated bugs, can reduce the outbreak of pests in that year.
The same can be used when taking the drug, such as spironoid ethyl ester, pyridin ether, or substitute urea insecticides such as juvenile urea, but it is recommended to give at least 2 to 3 consecutive doses of the drug during this period, and the interval between each time is about 10 days.
<h1 class="pgc-h-arrow-right" > note here is:</h1>
Because the rhododendron reticulated bug has a certain ability to fly, and its often harmful gathering place is mainly located on the back of the plant leaves, these have a certain impact on the control of pests.
Therefore, when we choose to spray control with drugs, we must pay attention to the direction of the spray head, and spray well to ensure that the drug can completely spray the front and back of the plant leaves.
In addition, in addition to the control period I mentioned, once you find that there are yellow-white spots on the leaves of the cuckoo in the area you are maintaining, or the leaves are gray-white as a whole, you must check whether there is a cuckoo reticulum bug on the back of the leaf, or the presence of black nymphs or black-brown feces, and once it is determined that it is caused by the harm of the rhododendron reticulated bugs, you must immediately use drugs for prevention and control.
Well, the prevention and control of rhododendron reticulated bugs will be briefly shared here today.
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