What common insect pests need to be controlled when growing roses?
What pests need to be prevented when growing roses? Please give an introduction. When growing roses, the following pests need to be prevented: 1. Cnidocampa flavescens (Walker), of the order Lepidoptera, family Limacodidae, also known as the slug moth, octagonal worm, octagonal jar, itching chili, poisonous hairy caterpillar. It is distributed in almost every province nationwide. Besides damaging roses, it also damages crabapple, jujube, redbud, mulberry, ...
What pests need to be prevented when growing roses? Please give an introduction.
When growing roses, the following pests need to be prevented:
1. Cnidocampa flavescens (Walker), of the order Lepidoptera, family Limacodidae, also known as the slug moth, octagonal worm, octagonal jar, itching chili, poisonous hairy caterpillar. It is distributed in almost every province nationwide. Besides damaging roses, it also damages crabapple, jujube, redbud, mulberry, apple, pear, peach, apricot, hawthorn, persimmon, pomegranate, elm and many other garden plants.
1. Damage characteristics
Young larvae gnaw the leaf mesophyll, making the leaves appear net-like and forming small white round translucent spots, which after a few days merge into large spots. After the larvae grow larger, they eat the leaves into notches and holes, and in severe cases only the main veins and petioles remain, leaving bare stems. In severe cases, this affects plant growth and development and may even cause death. The poisonous hairs of the slug moth sting people, causing pain and itching.
2. Morphological characteristics
Egg: oval, flat, 1.4 to 1.5 mm in long diameter and 0.9 mm in short diameter. The surface has line patterns; when first laid it is yellowish white, later turning pale yellow. It is mostly laid on the leaf surface, often in egg masses of dozens of eggs.
Pupa: 11 to 13 mm long, oval, plump, yellow-brown. The cocoon is calcareous and hard, oval, with several longitudinal stripes alternating grayish white and brown, resembling a sparrow egg, and is attached tightly to branches and trunks.
Larva: mature larva 16 to 25 mm long, plump, rectangular, yellow-green in body color. The head is relatively small, pale yellow-brown, hidden beneath the first segment of the prothorax. The prothorax is broad, yellow-green, with a prothoracic shield, crescent-shaped, with 1 dark brown spot on each side. On the dorsal side of the body there is 1 purple-brown dumbbell-shaped large spot with bluish edges. From the second segment of the trunk onward, each segment has 4 transverse rows of fleshy protuberances bearing spines and poisonous hairs, among which those on segments 3, 4, 10 and 12 are larger; there are also 9 pairs of branched spines on the lower sides of the body. The spiracles are red-green, with dark green upper and lower margins, and the spiracle area is pale yellow; each segment on the sides of the body has wart-like protuberances with yellow hairs, and the abdomen is pale yellow. The anal plate has 2 black dots; the thoracic legs are extremely small, the prolegs are reduced, and the ventral middle of abdominal segments 1 to 7 each has 1 flattened round "sucker". There are two blue longitudinal stripes on each side of the middle of the body.
Adult: body length 12 to 16 mm, wingspan about 35 mm. Body plump, yellow-brown, with the head, thorax and the front and rear ends of the abdomen yellow on the dorsal side. Antennae filiform, gray-brown; labial palps curved over the top of the head. Compound eyes spherical and black. The forewing has 1 brown slender line from the apex to the basal 1/3 of the posterior margin and near the anal angle; the outer side of the inner line is yellow-brown and the inner side is yellow; along the outer margin of the wing there is a brown slender line; the yellow area has 2 dark brown spots, both near the yellow-brown area, 1 near the posterior margin and 1 slightly before the middle of the wing. The hindwing is pale yellow-brown, without spots, and darker at the margin. The dorsum of the abdomen is yellow-brown, and the legs are brown.
3. Life habits
In North China there is 1 generation per year, overwintering as mature larvae in cocoons on branch forks and trunks. Pupation begins in mid to late May of the following year, with the pupal stage lasting about 15 days. Adults appear in June; they hide by day and come out at night, are phototactic, and mate and lay eggs shortly after emergence. Eggs are laid on the underside of leaves, singly and scattered; several eggs can be laid on 1 leaf, and they are semi-transparent. The egg stage lasts about 7 days. In July the larvae gradually mature and form cocoons on branches and trunks to overwinter.
4. Control methods (1) In autumn and winter, pick off insect cocoons or crush the cocoons on tree trunks to reduce the source of insects; (2) during the adult occurrence period, use insect-killing lamps to trap and kill adults; (3) when larvae are clustered and causing damage, remove infested leaves and manually capture and kill the larvae, taking care to avoid the larvae's poisonous hairs when capturing them; (4) before the larvae reach the 3rd instar, choose biological or bionic pesticides, such as 500 to 700 times dilution of Bt wettable powder with a content of 16000 IU/mg, 800 to 1000 times dilution of 1.2% bitter tobacco emulsifiable concentrate, 1500 to 2000 times dilution of 25% diflubenzuron suspension concentrate, 1500 to 2000 times dilution of 20% mipan suspension concentrate, etc.; (5) when larvae occur on a large scale, spray 2000 to 3000 times dilution of 20% fenvalerate, 1500 to 2000 times dilution of 2.5% deltamethrin, 1000 to 1500 times dilution of 50% phoxim emulsifiable concentrate, 1000 to 1500 times dilution of 20% cypermethrin-pyrethroid emulsifiable concentrate and other pesticides for control; (6) protect natural enemies such as the slug moth purple ichneumon wasp, mantises, stink bugs, etc.
2. Macrosiphum rosae, of the order Homoptera, family Aphididae. Besides damaging roses, it also damages Rosa multiflora, Rosa multiflora var. carnea and other garden plants of the genus Rosa in the family Rosaceae.
1. Damage symptoms
Nymphs and adult aphids gather on new shoots, tender leaves and flower buds to cause damage. The damaged tender leaves and flower buds stop growing and are difficult to extend, and excrement often sticks to the leaves, affecting ornamental value. In severe cases it induces sooty mold and causes plant death.
2. Morphological characteristics. Wingless parthenogenetic female: relatively large, body oval, 4.2 mm long. Head yellow to light green, thorax and abdomen grass green, sometimes orange-red. Marginal tubercles round, located on the prothorax and abdominal segments 2 to 5; the dorsum and ventral surface of the abdomen have obvious tile-like striae; the frontal tubercles of the head are raised and clearly protrude outward in a "W" shape. Antennae 6-segmented, filiform, pale in color, total length 3.9 mm, segment 3 with 6 to 12 secondary sensoria. Siphunculi black, long cylindrical, with reticulation at the tip and tile-like striae elsewhere, total length 1.3 mm, about 2.5 times the caudal plate. Cauda conical, pale, with transverse striae formed by small round protuberances on the surface, bearing 7 to 9 curved hairs.
Winged parthenogenetic female: body length 3.5 mm, body slightly greenish, mesothorax earth-yellow, each abdominal segment with median, lateral and marginal spots, segment 8 with a large and broad transverse band spot. Antennae 2.8 mm long, segment 3 with 40 to 45 round sensoria distributed over the whole segment and overlapping in arrangement. Wing venation normal. Siphunculi 0.76 mm long, 2 times the caudal plate, with 14 to 16 hairs. Other characteristics similar to the wingless parthenogenetic female.
Nymph: the newly hatched nymph is about 1 mm long, initially white-green, gradually becoming pale yellow-green, with red abdominal eyes.
3. Life history and habits. In North China, Macrosiphum rosae occurs 10 to 20 generations per year, overwintering as adult and nymph aphids in the bud axils of residual flower stem stubble. After roses sprout in spring, overwintering adult aphids reproduce on new shoots and tender leaves, and begin damaging tender shoots from early April; the flower buds and the underside of leaves can sometimes be covered with a layer. From mid-April, winged aphids appear one after another, and both the damaged plant rate and population density rise markedly. Mid-May is the first peak of reproduction; in July to August, high temperatures and continuous rainy weather cause population density to decline. When the average temperature is about 20°C, the climate is dry, and the relative humidity is 70% to 80% (that is, around May and October), reproduction is fastest and damage is most severe.
4. Control methods (1) After autumn, from late October to early November, prune and burn all stems above 10 to 15 cm; (2) biological control: pay attention to protecting natural enemies, use broad-spectrum pesticides as little as possible, and choose suitable biological pesticides. Spray 800 to 1000 times dilution of 1.2% bitter-tobacco emulsifiable concentrate for control; (3) when aphid density is relatively high, spray one of 1000 times dilution of 50% phoxim, 1000 times dilution of 50% fenitrothion, 2000 to 2500 times dilution of 20% fenvalerate, 3000 times dilution of 50% pirimicarb, 2500 to 3000 times dilution of 2.5% deltamethrin, 3000 to 4000 times dilution of 6% imidacloprid, etc. on the foliage, paying attention to safety when spraying; (4) apply 3% carbofuran granules to the roots, which can effectively control aphids and other pests; (5) protect predatory natural enemies such as Harmonia axyridis, green lacewings, hoverflies, etc.; (6) omethoate may cause phytotoxicity to peach, Amygdalus triloba, Chaenomeles speciosa and other plants of the family Rosaceae. When controlling aphids on such tree species, generally try not to use it.
3. Rose sawfly, of the order Hymenoptera, family Argidae. Also known as rose argid sawfly, rose three-segmented sawfly, rose three-segmented sawfly, yellow-bellied worm. In China it is mainly distributed in North China, South China, Southwest China, Central China, East China and other places. Besides damaging roses, the rose sawfly also damages Rosa multiflora, Rosa xanthina, Rosa multiflora var. carnea, Rosa rugosa and other garden plants.
1. Damage symptoms. The larvae bite and eat host leaves, often gathering in groups of dozens on a leaf. In severe cases they can eat the leaves completely, leaving only the coarse veins. Females lay eggs on branch tips, which can cause the branch tips to die, greatly affecting the normal growth of roses and the ornamental value of the flowers.
2. Morphological characteristics
Egg: long oval, orange-yellow, about 1 mm long, slightly thicker at one end, turning green shortly before hatching.
Pupa: head and thorax brown, abdomen brownish yellow, about 9 mm long.
Cocoon: oval, silky, about 11 mm long, grayish yellow.
Larva: larvae of instars 1 to 4 are green, with black head, thorax and legs; 5th-instar larvae have a brown head. Mature larvae are about 20 mm long, with an orange-red head. Antennae thick and short, pale red at the base. Thorax and abdomen yellow or orange-yellow, anal plate black and bearing fine setae. From the 2nd to the 8th thoracic segment, the dorsum of each has 3 transverse rows of dark brown hair-bearing tubercles, 6 per row, clearly arranged in 6 longitudinal rows; the remaining segments have 1 to 2 rows of hair-bearing tubercles arranged longitudinally. On the thorax and abdominal segments 2 to 8, below each spiracle there is 1 relatively large black hair-bearing tubercle. Prolegs 6 pairs, located on abdominal segments 2 to 6 and the last segment.
Adult: female adult body length 7 to 9 mm, wingspan 16 to 20 mm. Antennae 3.5 mm, 3-segmented. Body, wings and legs blue-black with metallic luster. The dorsum of the mesothorax is depressed in an "x" shape. The abdomen is orange-yellow, and on its dorsal side at the junction of thorax and abdomen there is a tongue-shaped black spot extending backward from the thorax. The ovipositor is double sickle-shaped, divided into upper and lower valves. The upper valve has 8 spiral ridge lines, and the lower valve has 9 toothed ridge lines. The saw has 12 sharp teeth. When not laying eggs, it is hidden in the genital groove at the end of the abdomen.
Male adult slightly smaller than female adult, body length 5.5 to 7.5 mm, wingspan 13 to 16 mm. Antennae 4.5 mm. Abdominal segments 1 to 3 and the center of the dorsum of segment 7 have brown transverse stripes. Forewings black, semi-transparent. Other features the same as the female adult.
3. Life habits
In North China there are 2 generations per year, overwintering as mature larvae making cocoons in the soil. Pupation occurs from April to May of the following year, adults emerge from June to July, and from September to October the second-generation mature larvae enter the soil to make cocoons and overwinter. When laying eggs, the female adult uses the sickle-like ovipositor to pierce longitudinal slits in the host's new shoots, arranged in double rows in a "V" shape; from the outside, strip-like oviposition scars 2 to 2.5 cm long can be seen, and after 3 to 5 days the oviposition scars are clearly exposed. Each female lays 30 to 40 eggs. After the eggs hatch, the new shoots almost completely split, turn black and break off. The egg stage is about 1 week. Newly hatched larvae crawl to nearby leaves to cause damage and have a clustering habit; after growing larger they disperse to feed, and when resting they often raise the last several abdominal segments.
4. Control methods (1) In winter and spring, dig for cocoons near the flowers and trees to eliminate overwintering larvae; (2) during the peak oviposition period of adults, prune off the egg-laying branch tips; (3) during the larval occurrence period, manually capture the larvae; (4) at the young larval stage, choose biological pesticides, such as 500 to 700 times dilution of Bt wettable powder with a content of 16000 IU/mg or 800 to 1000 times dilution of 1.2% bitter-tobacco emulsifiable concentrate, with good results; (5) during the larval occurrence period, use chemical pesticides, such as spraying 800 to 1000 times dilution of 90% trichlorfon crystal, 1000 to 1200 times dilution of 50% phoxim emulsifiable concentrate, 2500 to 3000 times dilution of 2.5% deltamethrin emulsifiable concentrate.
4. Aulacaspis rosarum, also known as rose white round scale, rose white round scale, of the order Homoptera, family Diaspididae. Besides damaging roses, it also damages Rosa multiflora, Rosa rugosa, Rosa xanthina, etc.
1. Damage symptoms
Nymphs and female adults fix themselves on branches and trunks and suck sap. When the infestation is severe, the entire branch and trunk are covered with scale bodies, and the damaged areas turn brown, causing tree vigor to decline. In severe cases it causes the plant to send out shoots poorly and even die.
2. Morphological characteristics
Egg: purplish red, long oval, about 0.16 mm in long diameter.
Nymph: newly hatched nymph orange-red, oval. Dark purple, with white waxy filaments secreted on it. Antennae 5-segmented, the terminal segment longest. The end of the abdomen has 1 pair of long hairs.
Adult: female scale cover grayish white, nearly round, 2.0 to 2.4 mm in diameter. There are two scale points; the first scale point is pale brown, near the edge of the scale cover and superimposed on the second scale point; the second scale point is dark brown, near the center of the scale cover. Male adult body length 1.2 mm, width 1.0 mm; head and thorax enlarged, widest at the mesothorax, with obvious head marginal processes. The lateral margins of the metathorax and pregenital abdominal segments protrude in lobes, initially orange-yellow, later purplish red. There are 3 pairs of pygidial lobes; the median lobe is located at the notch of the pygidium, with its bases connected by a yoke, the inner margin straight at the base, and the distal half sloping outward; the 2nd and 3rd lobes are all bilobed, with rounded tips. There are 5 rows of dorsal ducts, and the submedian groups of abdominal segments 2 to 4 are all in 2 rows, front and rear. Perivulvar pores in 5 groups. Male scale cover 0.8 mm long, 0.3 mm wide, white, waxy, nearly parallel on both sides, with 3 longitudinal dorsal lines on the back, and the scale point located at the front end.
3. Life history and habits
In North China there are 2 generations per year, overwintering as fertilized female adults and 2nd-instar nymphs on branches and trunks. Egg laying begins in early to mid-April of the following year; eggs are laid beneath the scale cover. The peak hatching periods are in early to mid-May and mid to late August, and each female lays about 130 eggs. Adults and nymphs often gather on branches and trunks more than 2 years old or in cracks in the bark to cause damage, and in severe cases they look like a layer of white flocculent material. After hatching, nymphs crawl out from beneath the scale cover and move slowly on the branches and trunks; after molting they fix themselves and cause damage. At this time, dark purple nymphs can be clearly seen on the branches and trunks, and the waxy filaments on the dorsal side of the body are faintly visible. There is overlapping of generations.
4. Control methods
(1) During the dormant period of roses, spray 5 degrees Baume lime sulfur mixture, or 8 to 10 times dilution of resin mixture, which can effectively reduce the overwintering population density;
(2) Combined with pruning and other management, promptly prune off severely damaged branches and leaves and bury them deeply in a centralized place;
(3) Apply 3% carbofuran granules to the roots, and water after application;
(4) Within 7 days after the peak hatching period of nymphs, before wax is formed or when the wax layer has just begun to form, spray the branches and leaves with 1500 to 2000 times dilution of 40% suprazine emulsifiable concentrate, 2000 times dilution of 6% imidacloprid soluble liquid, or 2500 times dilution of pyrethroid pesticides. Use the above three pesticides alternately, spraying once every 7 to 10 days, continuously 2 to 3 times, for good results. The key to spraying lies in seizing the timing (the nymph stage); once the scale cover is formed, spraying is unlikely to be effective.
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