The main causes of death in Sichuan pepper trees are leaf rust, root rot, black shank (gummosis), and pests such as longhorn beetles, leaf miners, green beetles, mulberry scale insects, and gall midges.
 
　　1. Longhorn beetles: These appear after the beginning of autumn. The larvae bore into the branches and trunks, causing the entire tree to die in severe cases. Control methods: During the autumn harvest, thoroughly prune and burn the infested branches or kill them with wire. Then, use cotton soaked in a mixture of kerosene or basil powder to plug the borer holes.

　　2. Swallowtail butterfly. Adults lay eggs on the undersides of tender buds or leaves, damaging the leaves and creating serrated edges. Control methods: Kill pupae during winter pruning, kill adults in summer, and spray the plants with aluminum thiocyanate to kill larvae.

　　3. Aphids. Primarily damage tree leaves. Control methods include: removing weeds from the ground, tree pits, and rock crevices in mid-to-late October to eliminate overwintering sites; spraying plants with a 1500-fold dilution of dimethoate emulsion in mid-April each year, or spraying with a 1:1000–3000-fold dilution of dichlorvos solution, or a 1:1000–2000-fold dilution of zinc phosphide emulsion, or a 1:4:400–500 solution of laundry detergent or urea. All these methods can achieve a control efficacy of 95%.

　　4. Leaf rust. This disease primarily affects the leaves, and is more prevalent in the humid summer and autumn. Initially, circular, pale yellow spots appear on the surface of the leaves, gradually darkening to yellowish-brown and producing powdery orange-red spores. Control methods: Spray with 0.3-0.5 Baume's lime sulfur solution or 1000 times diluted methyl thiophanate 1-2 times from June to August. In winter, combine pruning with removing and burning fallen leaves and weeds under the canopy, while simultaneously spraying with 2-3 Baume's lime sulfur solution.

　　5. Root rot. Infected seedlings and mature pepper trees show edema in the underground roots, with the root bark easily peeling off and emitting an unpleasant odor. Control methods: (1) The nursery should be located in well-drained sandy soil, and the seedbed should be raised with good drainage. Do not cultivate seedlings in soil with root rot. (2) Apply more phosphorus and potassium fertilizer during the seedling stage to enhance the seedlings' disease resistance. (3) If mature pepper trees are found to have root rot, promptly prune the diseased roots, disinfect the cut surfaces with lime sulfur mixture, and apply wood ash.

　　6. Sichuan pepper longhorn beetle. Adults typically emerge in June and July. During this period, adults should be manually captured on sunny, windless afternoons. Inspections should be conducted from May to August; any eggs or larvae found should be scraped off and killed promptly. Chemical control can be implemented from March to November each year using the following methods: (1) Apply a 1:20 dichlorvos or kerosene solution to the affected bark and surrounding area; this can achieve 100% effectiveness against third-instar larvae. (2) Apply a 0.3:1 dimethoate solution to the base of the trunk to kill young larvae under the bark. (3) Spray the pepper trees with a 1:2500 dichlorvos solution to kill adults through contact. (4) If adults bore into the trunk, soak cotton balls in dimethoate solution and insert them into the holes, then seal the holes with thin mud to suffocate them. When applying dichlorvos, kerosene, or dimethoate solutions to the trunk, ensure the trunk is not completely dry, otherwise severe phytotoxicity may occur.

　　7. Scale insects on Sichuan pepper trees. In late March, apply a 1:5 dilution of dimethoate solution to the tree trunk, 10 ml per tree, or inject 5-10 ml of undiluted dimethoate solution into each tree; in late May and late August, during the nymph and pupal stage, spray the Sichuan pepper tree trunk with a 1:1000 dilution of dimethoate and dichlorvos solution 2-3 times.

　　8. Sichuan pepper leaf miner. Farmers call it "fire wind." Control can be carried out in late April when the pepper tree buds are just beginning to emerge. ⑴ Spray with a 1:1:3:1000 dilution of dichlorvos, dimethoate, and methamidophos; the disease rate on young shoots can be reduced to below 1%. ⑵ Spray once with a 1:1600-1800 dilution of dichlorvos before the pepper tree flowers. ⑶ After the pepper tree flowers have faded, immediately spray once with an 800-1000 dilution of 40% dimethoate emulsion. Spray again 10 days later to prevent the larvae from spreading and causing damage.

　　9. Sichuan Pepper Leaf Beetle. Around the time Sichuan pepper matures, the larvae feed on the leaf tissue, causing many leaves to turn partially or completely yellow and shrivel. Numerous filamentous structures and holes appear on the underside of the leaves. Severe infestation can lead to premature leaf drop, affecting next year's yield and even causing plant death. Control methods: Spray with a 1:800–1000 solution of phosmet. When using fenitrothion or phoxim, spraying is less stable under sunlight; it is best to spray in the evening.