Occurrence and Prevention of Common Diseases of Pleurotus ostreatus

In recent years, with the expansion of cultivation area and the growth of cultivation years, the damage of pests is increasingly common, and presents a trend of early and rapid occurrence, serious when the mushroom has no harvest. Because Pleurotus ostreatus is sensitive to pesticides, it is easy to produce phytotoxicity. When pests occur, it is difficult to achieve the effect of pest control and mushroom protection. Therefore, identifying the damage characteristics of various pests and reducing the infection sources are effective measures to avoid and reduce the occurrence of pests.

1. Pest species

1. Eye fungus mosquito is also called pointed eye fungus mosquito, commonly known as small black mosquito, small fly, white maggot (refers to larvae). It belongs to Diptera, mosquito insects. Adults are 2 - 3mm long, brown or grayish brown, hairy, with a pair of membranous front wings and a pair of rear wings specialized as balance rods. The compound eyes are well developed, pointed at the top, extending from the top of the head and connecting left and right to form an eye bridge. Antennas filiform, 16 nodes, female abdomen end pointed, male abdomen end has a pair of pincer-like clasps. Larvae white transparent or milky white, the first hatching larvae 0.75mm long, 0.1mm wide, late 5.5mm, 0.5mm wide, a total of 12 nodes, no feet, black head, ossified, chewing mouthparts developed.

Adults are lively and good at flying, phototaxis, humus-loving, often live in unclean places (such as mushroom roots, weak mushrooms, rotten mushrooms and garbage) mating, laying eggs. Larvae like to live in groups in the culture medium and feed actively, damaging hyphae, primordia and young mushrooms, suitable for feeding senescent hyphae. At this time, if too much water is sprayed, it is more conducive to the growth and development of larvae, and it will cause disasters in a short period of time. Therefore, the mushroom shed with partial fruiting in autumn and winter and re-fruiting in spring will suffer heavy damage, light ones will affect the yield, and heavy ones will cause no harvest.

2. Gall midges alias mushroom flies, larvae said maggots. Diptera mosquito pests. Adult worms are weak, about 1~2mm long, yellowish or orange. Small head, large compound eyes. Antennas moniliform, 11 nodes, nodes have obvious hairs, male antenna is longer than female. The front wing is membranous and transparent with hairs, the wing veins have 3 longitudinal veins and 1 transverse vein, and the rear wing reduces to a balance rod. 3 pairs of feet are similar. The female has a pointed abdomen, while the male has a pair of pincer-like clasps. Larvae small body, about 2mm long, milky white at the beginning, orange or orange, long or spindle, head underdeveloped, a pair of short antennae, body points 13, transparent epidermis without feet. There are forked xiphoid pieces protruding from the mid-abdominal plate, which is the main feature of gall midge larvae.

Adults are not good at flying, have aggregation, phototaxis, and lay eggs in mushroom beds or storage yards. Gall midges mainly damage larvae. Larvae like moisture, can live in water. The larvae in the growth stage are harmful to the material, young buds and mushroom stems in the fruiting stage. The mushroom buds are yellow, wilted and dead. After the mature mushroom body was damaged, a large number of larvae gathered on the mushroom stem and the back of the mushroom, and a layer of orange powder appeared on the material surface when it was serious, which affected the commodity and yield of Pleurotus ostreatus. Because it is mainly larval reproduction, reproduction cycle is short, in a short period of time can occur.

3. Phistophaga is a diptera insect. Adult body length or small, light brown to black. Antennas short, 3-node, awn-shaped. Larvae transparent to milky white, pointed head, not ossified, abdomen blunt.

Mushroom ventilation is poor, humidity is too high, dead mushrooms rot mushroom not timely treatment, often cause flea flies adult eggs, reproduction damage. Larvae move quickly, invade from the base of the mushroom bud, bite the soft tissue to make the mushroom body tissue become loose sponge, and finally the whole mushroom bud is bitten empty. The higher the moisture content of the overburden, the more serious the occurrence.

4. Jumping insects, also known as ash worms, belong to the order Collembola insects. Jumping insects are wingless lower insects, 1~2mm in length, if, adult blue-purple, scattered gray-white spots, hair and wax powder, can move on water, the head has thick short tentacles. 3 pairs of feet, thick, with a pair of elastic organs on the 4th abdominal segment. Larvae color is white, body shape and adult similar, dormancy after peeling, color gradually dark. Most of them eat rot, some feed on Pleurotus ostreatus fruiting body, drill into mushroom stem and mushroom cover to feed, cause holes, reduce commodity value. When Pleurotus ostreatus springworms occur, a large number of springworms gather at the junction of stem and cap, invade pleat, make it appear reddish brown spots, once frightened, springworms will jump off from mushroom bed, hide in damp dark corner so as to become lumps. Jumpers can also carry pathogens and viruses.

5. Pest mites belong to arachnid, acarids. It has eight legs, like a spider. The main pests of Pleurotus ostreatus are Pyotyphus mites and acaroid mites.

(1) Pythagus pythagus is small, oblong to elliptic, light brown, short body wall hair, slow moving, likes to live in groups, invading hyphae, young buds and fruiting bodies. In the mushroom growth and fruiting period and under high humidity conditions, it reproduces quickly. When it reproduces to a certain extent, it migrates to the covering soil on the surface of the mushroom bed in groups, like a layer of khaki powder. If it is not controlled, the whole mushroom house will be destroyed in a few days, and the mycelium will be eaten up, resulting in no harvest.

(2) Acaroid mites are bigger, round and white than Pyotyphus, and have some long hairs on their body wall. Single action, hyphae feeding, saprotic. When the fungus bed grows big, it can make hyphae decline, but it does not cause no harvest.

II. Control methods

Prevention should be the main way to control Pleurotus ostreatus pests, and comprehensive control should be taken.

1. Do a good job in environmental sanitation of mushroom farm. Livestock sheds, manure, grain warehouses, weeds, wastes, sewage ditches, etc. around mushroom houses are the main habitat and breeding places for pests. Every spring is the recovery period of various pests. Keep clean environment inside and outside mushroom houses, and clean up wastes, sewage and gravel in time. Both old and new mushroom houses had better be fumigated with formaldehyde and potassium permanganate before use, and cotton wool should be hung in mushroom houses during fruiting period to achieve insect control effect.

2. Mushroom installation of 60 mesh screen doors and screens, both ventilation and light transmission, but also to prevent pests from entering.

3. The raw materials for cultivation of oyster mushroom with insects are more or less with pests. Generally, fresh and mildew-free raw materials are selected. Insecticide treatment is carried out before use, such as exposure, chemical mixing, etc. For the raw materials with more pests, it can also be fermented for a short time, generally accumulated for 5~7 days, turned twice, and the material temperature is controlled at about 60℃, which can kill the insects and eggs in the material. The material treated above can reduce the harm of pests from the period of fungus development to the initial stage of mushroom production.

4. To avoid bacteria with insects prohibited with insects of the fruit body seed production, to use clinker as a substrate for the production of bacteria.

5. Use light trap adult mushroom room built-in bulb or lamp tube, below put basin, drip waste oil, flies, mosquitoes and other pests will come to light, stick and die. Conditions can be installed black light trap effect is better.

6. Sweet and sour liquid to treat insects eye fungus midges, gall midges and other phototactic pests, can be used 3 parts sugar, 4 parts vinegar, 1 part white spirit, 1 part dichlorvos and 91 parts water mixed evenly, then cloth or cotton ball dip medicine, take out wrung dry cover on the material surface, pests climb on the medicine cloth or cotton that is poisoned. A mixture of 1 part honey, 10 parts water and 2 parts 90% trichlorfon can trap and kill springworms.

7. Management should be appropriate in the cultivation and management process of Pleurotus ostreatus, especially during the reproduction of pests, control measures should be appropriate, otherwise it will also lead to the invasion of pests. The key points of management are as follows: the fungus bed should be covered tightly during the growth period, and attention should be paid to preventing pest invasion during ventilation; the disposable amount of water should be strictly controlled during the fruiting period to prevent the accumulation of water in the fungus bed; the harvest of each batch of mushrooms should be achieved as much as possible to avoid the mushroom bed being exposed for too long, so as to reduce the number of eggs laid by pests on the fungus bed; when pests are found during the fruiting period, 25% chrysanthemum ester 2000 times solution can be sprayed; after harvest, the mushroom bed should be cleaned in time and covered tightly.