What are the control methods for diseases and pests of Euodia rutaecarpa?

(1) Sooty mold. After Euodia rutaecarpa trees are damaged by aphids and cottony cushion scale, irregular dark brown sooty patches are induced at the damaged sites and on the leaves, young shoots and trunks below them, and the affected areas appear to be covered with a layer of sooty material. Severely affected plants have weakened tree vigor and bear few flowers and fruits. Damage is severe from early May to mid-June.

Control methods: During the occurrence period of aphids and scale insects, spray 40% dimethoate 1500-2000 times dilution or 25% phoxim 800-1000 times dilution, once every 7 days, for 2-3 consecutive sprays; during the occurrence period of sooty mold, spray Bordeaux mixture at 1:0.5:150-200, once about every 10 days, for 2-3 consecutive sprays.

(2) Rust disease. In the early stage of the disease, yellow-green, nearly round, indistinct small spots appear on the leaves, then slightly raised orange-yellow pustules (the summer spores of the pathogen) form on the underside of the diseased leaves; as the spots on the leaves increase, the leaves wither and die. It occurs in mid-May and causes severe damage from June to July.

Control methods: During the disease period, spray 0.2-0.3 degrees Baume lime-sulfur mixture or 25% triadimefon 1000 times dilution, once every 7-10 days, for 2-3 consecutive sprays.

(3) Brown longhorn beetle. Also known as the trunk-boring worm. The larvae bore in from the trunk and feed on the xylem, forming irregular winding tunnels filled with frass and excrement, with ventilation and excretion holes at regular intervals to expel the frass and excrement out of the holes; damage is severe from July to October.

Control methods: From May to July, during the peak emergence period of adults, manual capture can be carried out; at the egg-laying cracks, use a small knife to scrape out the eggs and newly hatched larvae; after the larvae bore into the xylem, new borer holes appear on the trunk, and medicated cotton soaked in 80% dichlorvos stock solution can be inserted into the holes or 800 times dilution poured in, then the holes sealed with mud so the larvae suffocate and die; the longhorn beetle bethylid wasp can be tried for control.

(4) Citrus swallowtail butterfly. The larvae bite and feed on young buds and tender leaves, causing notches or holes; after the third instar, their food intake increases greatly, and they can eat all the leaves on young branches. It reproduces 3-4 generations a year. It overwinters as pupae attached to branches and other attachments, begins to occur in March of the following year, and causes severe damage from May to July. Adults are active during the day; after mating, eggs are laid on tender leaves, and after hatching, the larvae feed on tender leaves and cause damage.

Control methods: For young larvae, spray 90% trichlorfon 800 times dilution, once every 5-7 days, for 2 consecutive sprays, or use Bt emulsion 300 times dilution, once every 10 days, for 2-3 consecutive sprays.