What are the control methods for the cotton stem borer (Zeuzera coffeae) in cotton?
What diseases occur during the boll stage of cotton? How should they be controlled? How are cotton boll-stage diseases controlled? The occurrence of cotton boll-stage diseases is closely related to climate, variety, insect pests, and cultivation techniques during the growth period. Therefore, the control of cotton boll-stage diseases should adopt comprehensive control measures focusing on cultivation management, combined with chemical protection. (...
**How do you control the cotton stem borer (Zeuzera coffeae) in cotton?Scientific name Zeuzera coffeae Nietner, order Lepidoptera, family Cossidae.
Aliases: coffee carpenter moth, coffee leopard moth, leopard-print carpenter moth, coffee black-spot carpenter moth.
Distribution: eastern and southern China; in Shanghai and Taiwan, China it mainly damages cotton and trees.
Hosts: cotton, tea, mulberry, jute, castor bean, coffee, lychee, longan, citrus, pear, persimmon, loquat, peach, grape, jujube, etc.
Damage characteristics
The larvae bore into and feed on the stems of cotton and jute, causing the upper part or the entire plant to wither and die; when damaging mulberry, tea and fruit trees, the larvae bore into the xylem of branches and trunks, gnawing an outward row of frass holes at intervals, mostly boring upward along the pith, causing branch breakage or withering.
Morphological characteristics
Adult body length 11-26mm, wingspan 30-50mm, male smaller than female, body grayish white. Female antennae filiform, male basal half plumose and apical part filiform, all black, covered with white scales. There are 6 blue-green spots on the thorax dorsum arranged in 2 longitudinal rows; each abdominal tergite has 3 transverse rows of blue-green longitudinal stripes, with 1 blue-green spot on each side and 3 spots of the same color on the venter. The spaces between veins of the forewings and hindwings are densely covered with blue-green short oblique markings, and the outer margin vein ends are spotted. The spots on the hindwings are lighter in color. The female has 1 relatively large blue-green round spot at the middle of the hindwing. Egg elliptical, length 1mm, cream yellow to brown. Larva body length 20-35mm, red, head yellowish brown or light reddish brown, pronotal shield yellowish brown to black, near the posterior margin center with 4 rows of backward comb-like tooth rows, ventral proleg crochets in a biordinal circle, anal plate dark brown. Pupa length 16-27mm, brown and glossy, abdominal segments 2-7 each with 2 transverse ridges on the dorsum, posterior end with 6 pairs of spines.
Life habits
In Shanghai and the Yangtze River basin, 1 generation per year; in Jiangxi, Taiwan, China and other places, 2 generations per year, all overwintering as larvae in the stems and trunks of cotton, wood molds, peach trees and various other trees. In Shanghai, pupation occurs in early to mid-June, emergence in mid to late June, and eggs are laid on cotton leaves. Newly hatched larvae bore into cotton petioles or thin branches to damage them; after the larvae grow slightly larger, they move to bore into thick branches or the main stem, disrupting the cotton's water supply; larvae damaging tea trees, mulberry and fruit trees bore upward along the pith. In the 2-generation area, in Jiangxi pupation occurs from mid-April to late June, the pupal stage lasts 13-37 days, and emergence occurs from mid-May to mid-July. Adults hide by day and come out at night, are phototactic, and mate and lay eggs soon after emergence. Eggs are laid in masses in bark crevices and holes, the oviposition period is 1-4 days, a single female lays 224-1132 eggs, adult lifespan averages 43 days, and the egg stage is 9-15 days. Newly hatched larvae gather on the egg mass and feed on the egg shells; after 2-3 days they crawl to the upper part of branches and trunks, spin silk and drop down, dispersing with the wind. The larvae bore in from the bud axils above the branch tips, and the part above withers; after 5-7 days they move to damage thicker branches. When boring in, they first girdle horizontally once beneath the bark, so the upper part mostly dies, then bore upward within the xylem. After maturing, they bore an emergence hole outward and then build a pupal chamber in the tunnel to pupate. At emergence, the head and thorax protrude from the emergence hole, and the pupal shell remains at the opening. The first-generation adults occur in August-September, and the second-generation larvae overwinter after autumn in the tunnels of damaged branches. Natural enemies include braconid wasps and Fusarium moniliforme.
Control methods
(1) In cotton fields, in conjunction with the control of other pests, collect cotton stalks early for centralized treatment or burning to reduce overwintering larvae in the stems.
(2) When sawdust-like frass is found around damaged wood molds, fruit trees and other host trees, promptly prune out and burn the infested branches to prevent adults from entering cotton fields to lay eggs after emergence.
(3) When cotton plants are damaged, split open the cotton stem and kill the larvae.
(4) When tea trees, mulberry and fruit trees are damaged, promptly prune out the damaged branches and burn or deeply bury them centrally; after 1-2 years they can be brought under control.
(5) During the peak emergence period of adults, in conjunction with the control of other pests, spray 50% parathion emulsifiable concentrate at 2000 times dilution, or 10% bromine-malathion emulsifiable concentrate at 1000 times dilution, 20% pyrethroid-malathion emulsifiable concentrate at 1500 times dilution, 20% chlorine-malathion emulsifiable concentrate at 2000 times dilution, 2.5% Kung Fu emulsifiable concentrate at 3000 times dilution, 21% Mieshabi emulsifiable concentrate at 3000-4000 times dilution, 30% Taoxiaoling emulsifiable concentrate at 2500 times dilution, 2.5% Uranus emulsifiable concentrate at 1500 times dilution.
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