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 to control cotton boll-stage diseases? The occurrence of cotton boll-stage diseases is closely related to climate, variety, insect pests, and cultivation techniques during the growth period. Therefore, control of cotton boll-stage diseases should adopt integrated control measures focused mainly on cultivation management, combined with chemical protection. (...
**How to control the cotton stem borer (Zeuzera coffeae) in cotton?Scientific name Zeuzera coffeae Nietner, Lepidoptera, 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, 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 a row of frass holes outward 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 cyan-blue spots on the thorax dorsum arranged in 2 longitudinal rows, 3 transverse rows of cyan-blue longitudinal stripes on each abdominal dorsum segment, 1 cyan-blue spot on each side, and 3 spots of the same color on the venter. Dense cyan-blue short oblique markings between the veins of the forewings and hindwings, with spots at the vein ends of the outer margin. Hindwing spots lighter in color. The female has 1 relatively large cyan-blue round spot in 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 posteriorly comb-like tooth rows, ventral prolegs with biordinal circles of crochets, anal plate dark brown. Pupa length 16-27mm, brown and glossy, the dorsum of abdominal segments 2-7 each with 2 transverse ridges, abdominal 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 leaf 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 2-generation areas, Jiangxi pupation occurs from mid-April to late June, pupal period 13-37 days, emergence 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, oviposition period 1-4 days, eggs per female 224-1132, average adult lifespan 43 days, egg period 9-15 days. Newly hatched larvae gather on the egg mass and feed on the eggshells; after 2-3 days they crawl to the upper part of branches and trunks, spin silk and drop down to disperse 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 make a transverse ring girdle under 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 extend out of 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 control of other pests, collect cotton stalks early and treat them centrally or burn them 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 infested branches to prevent adults from emerging and entering cotton fields to lay eggs.
(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 affected branches and burn them centrally or bury them deeply; this can bring it under control after 1-2 years.
(5) During the peak emergence period of adults, in conjunction with control of other pests, spray 50% parathion emulsifiable concentrate 2000-fold dilution, or 10% bromine-malathion emulsifiable concentrate 1000-fold dilution, 20% pyrethroid-malathion emulsifiable concentrate 1500-fold dilution, 20% chlorpyrifos-malathion emulsifiable concentrate 2000-fold dilution, 2.5% kung fu emulsifiable concentrate 3000-fold dilution, 21% miehsaibi emulsifiable concentrate 3000-4000-fold dilution, 30% taoxiaoling emulsifiable concentrate 2500-fold dilution, 2.5% tianwangxing emulsifiable concentrate 1500-fold dilution.
Click to get massive cotton cultivation techniques
Click to get massive grain and oil crop cultivation techniques