Lilac Pest and Control Methods
As a courtyard ornamental product, lilacs have been plagued by pests in recent years, causing concern for growers. The two major pests, leaf miners and scale insects, are damaging the health of the plants in different ways. This article deeply analyzes the characteristics of the two pests and provides scientific control methods to help you create a healthy and lush lilac bush.
Analysis of Lilac Leaf Miner Pest
Identification of Abnormal Leaf Symptoms
The larvae of the leaf miner cause double damage through their unique feeding method: the adults create circular perforations with a diameter of 0.5-2mm on the leaf surface, while the larvae build winding galleries inside the leaf tissue. This three-dimensional destruction leads to a significant loss of chloroplasts, and infected leaves show yellow and white mottling, with photosynthetic efficiency decreasing by over 40%, and severe cases resulting in the entire plant becoming withered.
Comprehensive Control Technology System
A full-year control calendar needs to be established for prevention and control: implement garden cleaning in November, remove old bark and paint with lime water; spray lime sulfur before germination in March; alternate the use of abamectin (2000 times) and cypermethrin (1500 times) during the peak larval hatching period in May, with a 7-day interval for two consecutive applications. The use of yellow boards can reduce the adult population by 30%.
Response Plan for Lilac Scale Insect Infection
Judgment of Abnormal Characteristics of Branches
Scale insects harm the phloem through刺吸式口器, initially appearing as white waxy secretions on the branches, with the pest density reaching up to 200 insects per 10cm branch section in severe infections. The affected area shows brown necrotic spots, accompanied by sooty mold disease, leading to a 60% reduction in new shoot growth and a significant decrease in flower bud differentiation rate.
Step-by-Step Management Strategy
Adopt a combination of physical and chemical joint control: when a few insects are found, use a hard-bristle brush dipped in 75% alcohol to mechanically remove them; spray 22% spirotetramat suspension concentrate 4000 times liquid during the nymph stage (late May); use 40% chlorpyrifos granules (5g/plant) during the adult stage. Combine with pruning dense branches to maintain a 50cm ventilation belt between plants.
By establishing a pest monitoring and early warning system, combined with optimized cultivation management, the resistance of lilacs to pests can be significantly improved. It is recommended to check the leaf back monthly, maintain a soil pH of 6.5-7.0, and apply phosphorus and potassium fertilizers to enhance plant resistance. Remember, preventative control is more effective in ensuring the healthy growth of lilacs than post-disaster remedies.