Melon fly: control methods and danger to humans

The African melon fly (Bactrocera cucurbitae (Coquillett)) is a pest that attacks the fruits of melon crops, making them unfit for consumption. As a result of the vital activity of this insect, crop loss can be 70-100%. The pest has a fairly long life cycle; it is capable of repeatedly breeding offspring per season. Harm to crops is caused by adults and their voracious larvae.

Description of appearance

The pest looks like a fly and has a different color. A small insect up to 7 mm long. The color is yellow with round dark spots. The body is covered with hairs. The wings are transparent, variegated, with yellow transverse stripes. A photo of the melon fly is presented below. The eggs are milky white, oblong. The larva is up to 10 mm long, cylindrical in shape, without legs, and resembles a caterpillar. On the last segment two tubercles stand out.

What types of houseflies are there?

The concept of “housefly” cannot be assessed unambiguously. Considered from a biological perspective, the housefly is a separate species with its own description. From the point of view of the average person, any insect that has wings flies around the house. There are ordinary ones, gray or black in color, which, when the windows are open in the summer heat, live on window sills or ceilings, irritating the ear with their annoying buzzing. The housefly is one of the varieties of the housefly, which is distinguished only by its slightly larger size. And there are flies with a beautiful green color and smoky wings, and this is where you should be wary. The green (carrion) fly is an inhabitant of very polluted areas, feeds on corpses and lays its eggs there. It is a carrier of various infectious diseases.

Lifestyle

The puparia overwinters in the soil where infected crops grew. In spring, when the temperature rises to +15 degrees Celsius, an adult melon fly appears. For about a week, adults feed on flower nectar and fruit juices. Summer time coincides with the flowering period of melons. The first mating season lasts up to one month. In total, 3 generations of melon flies are replaced during the season.

On a note!
After mating, the females begin laying eggs. Do this one egg for each fruit. Each female lays up to 120 eggs. The process lasts 30 days. Under favorable conditions, after 3-4 days, larvae appear, penetrate into the pulp of the fruit, and begin to actively feed on juices.

The maggot develops for about 18 days, then leaves the fruit, falls to the ground, and pupates. After a few days, an adult fly appears, ready to reproduce. The pupal phase lasts 10-20 days in summer, 45 days in autumn. During the puparia phase it overwinters.

Damage caused by the pest

These insects attack many cultivated plants. For example, you can often see leafminer flies on cucumbers, nightshades and cruciferous vegetables. Every puncture made by an adult and every hole gnawed by hungry larvae violates the integrity of the leaves of the prey plant. In addition, they feed on its nutritious juice.

All this leads to the fact that:

You can see light dots on the leaves, often with necrosis of the cells around them;
the leaves gradually wither and fall off;
in bulbous plants the bulb softens and rots;
the plant slowly dies.

Due to damage to leaves, their area participating in photosynthesis is reduced. In combination with the larvae sucking out cell sap, the plant weakens and therefore becomes susceptible to various diseases.

Sabotage

Larvae and adults pose a threat to melon and pumpkin crops. This dangerous quarantine pest parasitizes the fruits and seeds of the following crops:

melon;
common watermelon;
common cucumber;
snake melon;
wild melon (Cucumis trigonus);
squirting cucumber;
pumpkin.

The percentage of crop damage in places where the melon fly is spread reaches 70-100%. The larvae make passages in the pulp, making it unfit for consumption. Bacteria penetrate there and rotting processes begin.

Melon fly

Adult flies make punctures in the melon, from which juices appear, which the adults feed on. With numerous punctures, the fruit begins to rot, infection penetrates into the holes, and fungal diseases develop.

On a note!
The first sign of the presence of a dangerous pest is the presence of dark spots, tubercles on the skin of a melon or other fruit. In the process of parasitism of the larvae, rotting begins from the inside.

How to detect a pest in melon beds

The melon fly is a pest that is quite difficult to identify at the initial stage of infestation. It is possible to determine when signs of the vital activity of these insects appear. They are characterized by small dots, tubercles on fruits and shoots of plants, in places where they are punctured by females. Fungi and bacteria enter open wounds, which leads to rotting and darkening of the puncture sites.

At the stage of emergence of the larvae, the signs become clearly pronounced. The fruits lose their elasticity and begin to rot quickly. Moreover, this happens already 4-5 days after the appearance of the larvae.

Can I eat contaminated melons? The insect does not pose a danger to humans. It does not carry dangerous diseases and does not bite. But it is not recommended to eat fruits in which melon fly larvae have settled inside. In the process of life, they damage the pulp and seeds, which causes the development of rot in the damaged areas.

In affected fruits, the pulp loses its elastic consistency and begins to emit an unpleasant odor. Eating affected melons leads to disruption of the digestive system.

Methods for controlling melon fly

To destroy pests, several control methods are combined, and preventive measures are required.

Agrotechnical methods include:

deep plowing of the soil after harvesting, before sowing new beds;
compliance with crop rotation;
the use of hybrids that are resistant to damage by larvae, diseases, and fungal infections;
destruction of the remains of the infected plant by burning.

Before planting seeds in the soil, pre-soaking in chemicals is recommended. Treatment of melon against melon fly with insecticidal preparations is allowed at the stage of appearance of the first leaves. It is forbidden to spray formed fruits with a poisonous agent. Some chemicals are introduced into the soil along with fertilizers. Do not use toxic substances during the flowering period of crops, 20 days before harvest.

Chemical sterilization of insect pests

Work to reduce the fertility or completely stop the reproduction of insects began in the late 40s of the 20th century. Soviet researcher I.A. Rappoport was one of the first to discover the sterilizing abilities of certain chemical substances acting on insects. A little later, this technique was developed in the USA and other countries. Not only crop protection specialists, but also oncologists have become actively interested in chemical compounds that block the growth of unwanted cells.

The most effective for sterilizing insect pests were preparations based on thiophosphoric acid triethylenimide and phosphoric acid triethylenimide. Thus, to protect tomatoes from the Drosophila fly, by adding sterilized individuals to the pest population (25 specimens per mature one), it was possible to reduce the Drosophila population size by 82% in two months. Chemically sterilized insects have also been used extensively against the American white butterfly and boll weevil.

The effect of chemical compounds to sterilize insect pests was manifested through delayed development of gonads, death of formed eggs or sperm, as well as the ability to control the fertilization process and other results to reduce the population. Chemical sterilization of insect pests was carried out taking into account the drug used and the stage of development of the pest. Pupae, for example, were placed in chemical solutions for some time, larvae received their dose in specially created synthetic environments, adults were most often treated by contact, through the surface of the integument or limbs.

However, further research has shown that some chemical compounds used to sterilize insect pests can be toxic and even carcinogenic to warm-blooded fauna. This has slowed the wider adoption of chemical sterilization and left scientists with a challenge: finding safe mechanisms for its use.

Effective methods

Before flowering, the crop can be sprayed with chemicals. The most commonly used are Fufanon, Karbofos, Iskra, Aktara, Decis Profi, Arrivo. Protection lasts for 20 days. The solution is prepared immediately before processing the plants. You can buy the drug in a specialized hardware store. Price per dose from 10 rubles.

Preparations for melon fly

On a note!
From folk remedies, you can treat the bed with a solution of ammonia - 10 5 ml of ammonia per 10 liters of water. You need to water the soil, making sure that the product does not get on the leaves. Repeat the procedure twice a month. The pungent odor repels adults, but does not affect the larvae.

If pests are detected, damaged fruits should be destroyed. To prevent infection of the future crop, agrotechnical control methods are used.

Cherry fly - how to identify it?

This miniature fly is difficult to see; the presence of a pest in the garden can only be determined by the presence of wormholes in the berries of cherries. The following signs indicate that there is a pest in the garden:

Black dots are visible on the berries that begin to fill, these are traces of punctures of the skin by the insect's ovipositor. The fly left an egg in this place, from which a larva will appear after a while.
Later, a depression forms at the puncture site, and the berry begins to rot.
The presence of a worm in a berry can be determined by external signs: the pulp becomes soft, and the skin acquires a matte tint, its characteristic shine is lost.
When you break the berry inside, you can see a small white worm.

You can protect your crop from the pest if you take care of its detection in advance. To do this, in the spring, when flies begin to emerge after wintering, sticky traps are made. The simple device consists of a small piece of plywood or thick cardboard coated with yellow paint and a sticky substance.

This can be any glue that does not dry for a long time, for example, ALT. The trap is attached to a tree and observed. If more than 2 flies are detected per day, then their flight has begun, and the trees need to be treated with insecticides.

Appearance and stages of development

The cherry fly can be easily recognized by its appearance. It is small, no more than 5.5 mm in size, with a shiny black body, yellow paws and head. She has green eyes and an orange shield. The insect belongs to the variegated wing family.

If weather conditions are favorable, the insect completes its full life cycle in one year.

Pupae turn into adults (imago) in spring when the soil temperature reaches 10⁰C. This happens in mid-May, when the acacia begins to bloom. Before laying eggs, females need increased nutrition.

Juice of berries, secretions of aphids, wound acid of leaves make up their diet. After 14 days they begin to mate and lay eggs.

The flight of the cherry fly continues in June and early July, so it can destroy a significant part of the cherry and cherry crop. Having completed laying eggs, the females die.

White worms 0.5 mm in size - fly larvae - emerge from eggs about a week after laying. Feeding on the pulp of the berry, it moves deeper into the seed. The larval stage lasts 15-20 days. During this time, the pest increases significantly in size, reaching 7 mm, and leaves the berry. Once on the soil, it pupates.

In June, the first pupae appear, but do not develop this season, since they need to undergo cooling to complete the life cycle of development. Therefore, the insect in the pupal stage remains unchanged until next spring.

Preventive measures against cherry fly

The pest can be destroyed using chemicals - insecticides. But for early cherries this method cannot always be applied, since the ripening of the berries very often coincides with the beginning of the flight of the fly.

Adherents of organic farming use folk remedies and organic preparations. Everyone can choose a suitable method of protection from the front sight.

A good result comes from the comprehensive use of protective equipment. In addition to treating trees with pesticides and biological products, it is recommended to carry out the following preventive measures in the garden:

remove all spoiled berries from the trees; they may contain larvae that will become flies next year;
remove all carrion under the trees, remove it from the site or bury it to a depth of 0.5 meters;
If you dig up tree trunk circles within the crown in late autumn and early spring, the insect pupae will die from frost or become food for birds.

Biological and chemical agents

The fight against cherry flies involves timely treatment of plants with insecticides. It is recommended to use them during the mass emergence of the pest, in the second half of May. Secondary treatment is carried out after two weeks. At this time, females begin laying eggs.

For treatment, insecticides intended against flying pests are used. It is advisable to carry out secondary treatment with another means, this will prevent insects from becoming accustomed to the toxic substance and increase efficiency. The following chemicals are used:

Confidor;
Aktellik;
Calypso;
Maxi

An alternative to chemical preparations are microbiological ones. These drugs are not harmful to the environment and can be viral, fungal or bacterial.

To treat trees against cherry flies, it is recommended to use Nemabakt, Fitoverm, Lepidocid. Controlling pests and beneficial insects requires a lot of knowledge and effort.

The use of both chemical and biological protection agents at the same time is not advisable, as this can lead to the death of beneficial insects.

Folk remedies

In cases where plants cannot be sprayed, the following folk remedies are used:

in April, cover the tree trunk circles with agrofibre, this prevents flies from flying out, since the pupae will remain under it;
They treat trees with strong-smelling solutions based on herbs: tobacco, wormwood, garlic, pine needles;
hang insect traps.

African melon fly

The official name is Bactrocera cucurbitae coquillett. Lives in tropical countries, parasitizes all year round. Distributed in Africa, Asia, USA, Oceania. Affects 125 species of plants from the pumpkin family:

melon (Cucumis melo);
giant pumpkin (Cucurbita maxima);
watermelon (Citrullus lanatus);
cucumber (Cucumis sativus);
pumpkin (Cucurbita pepo);
citrus fruits (Citrus);
papaya (Carica papaya);
mango (Mangifera indica).

Symptoms of damage are punctures in the peel, signs of rotting. Spread with infected fruits and soil. The fight is carried out using combined methods.

What kind of insect is this?

Mining flies (or flies) are a whole family Agromyzidae (lat.), which includes about 3000 species. All of them are dipterous insects. These are small flies; the massive thoracic region is clearly visible in the structure. Other distinctive features of the family are a wide abdomen, short legs and transparent wings, slightly sparkling in the sun.

The greatest species diversity was noted by biologists in Germany. There are 350 species of insects found in this country. In Russia, in regions with a temperate climate, there are much fewer of them - about 100. The most common of them are:

herbivorous – Liriomyza strigata;
polyphagous – Phytomyza horticola;
chrysanthemum leaf – Phytomyza syngenesiae;
nightshade – Linomyza bryoniae, etc.

These species infect cultivated plants, causing harm to agriculture and ornamental floriculture.

Life cycle of an insect

Flies are characterized by bisexual reproduction: individuals of different sexes mate, after which, after some time, the female lays a clutch. She places her special organ - the ovipositor with a sharp end - deep into the leaf blade of plants. After such punctures, light green dots remain on its surface, which fade over time. Moreover, only 15% of the holes created in the leaves are needed for laying: all other injections serve to feed the adult miner fly.

When 2 to 5 days have passed, the larvae are born. In order to grow as quickly as possible and move to the next stage of development, they begin to feed heavily. To do this, the larvae gnaw the leaves of plants, creating a branched system of passages in them, which are called “mines.” This is where the name of the whole family came from.

When the resources of one leaf are exhausted, the larva begins to move along the stem and branches of the plant in search of a new place to feed. After 2 weeks, it is time for pupation. The larva gnaws the surface of the leaf, crawls out and moves to the ground. There, under a thin layer of soil, it will become a pupa, from which a new fly will then emerge. In total, the transformation cycle from egg to adult insect takes 25 days (at an air temperature of 20 °C).

Processing means

To prevent the occurrence of diseases and protect plants from pests, it is necessary not only to observe crop rotation, not to plant melons in heavy soil, but also to treat the seeds in solutions of potassium permanganate, formalin, and “Fundazol”.

Having discovered the first signs of the disease, melons are sprayed with herbal infusions and various folk remedies are used. If their treatment is ineffective, fungicides are used in the form of colloidal sulfur, Bordeaux mixture, and Fitosporin.

If pests appear on melons, other methods are needed to cope with them. Insecticides destroy melon aphids, spider mites and wireworms. Chemical preparations, “Bi-58”, “Aktara”, are most effective in combating parasites. But after spraying them, the fruits cannot be consumed for three weeks.

Melon diseases

Insects that gnaw through the leaves and fruits of melons spread pathogenic microorganisms - viruses and bacteria that cause various diseases in melons. Infection also occurs through untreated seeds, remains of stems and roots.

In unfavorable weather and excessive humidity, fungi multiply, which also often leads not only to a decrease in yield, but also to the death of the plant.

Fusarium wilt (fusarium wilt)

The disease, which begins with rotting of the roots, affects the entire vascular system of late and mid-ripening melons. A fungal infection from the ground rises to the stems. When affected by fusarium, the basic functions of the plant are disrupted; it dies because the mycelium clogs the blood vessels and releases toxins.

Contribute to the development of the disease:

improper care;
dense planting;
water stagnation;
excess humidity;
heatwave.

Melon leaves infected with fusarium wilt lose their green color and become covered with spots of an unpleasant grayish color. The diseased plant dies within a week.

To prevent the occurrence of fusarium, the seeds must be treated with formaldehyde before planting; before melon buds form, they should be sprayed with potassium chloride. Agronomists advise choosing a place for crops not in the lowlands, but in the hills.

Gray mold

Cold weather combined with prolonged rains increases fungal activity. They affect young fruits, melons become moldy, turn black, and soften. The disease develops quickly at low temperatures and subsides with heat.

Powdery mildew

The stems and leaves of the melon crop are often covered with small spots that quickly spread throughout the above-ground part of the melon. The brown tint of the plant indicates that it has been affected by powdery mildew. With further development of the disease, the leaf plastics curl and the stems dry out.

Having noticed the first signs, melon plantings are sprayed with a solution of sulfur powder. The treatment is repeated several times, the last time - 3 weeks before the fruit ripens.

Downy mildew (peronospora)

Yellow spots sometimes suddenly appear on melon leaves, and the lower part of the leaf becomes covered with a purple coating. With sharp fluctuations in temperature and high humidity, downy mildew develops quickly. The fungi that cause the disease penetrate the spores of the leaves, and the plant dies.

To prevent the appearance of powdery mildew, the seeds of the crop are heated in hot water or soaked in a solution of potassium permanganate. Melon beds in which specimens infected with peronosporosis are found are sprayed with urea or Bordeaux mixture.

Cucumber mosaic

Viruses carried by insects cause serious diseases in melon crops. If the leaves on young plants curl and become deformed, and tubercles appear between the veins, this indicates an infection with cucumber mosaic. As the disease progresses, the stems become covered with cracks, flowers fall off, and the surface of the melon is disfigured.

Root rot

Weak plants are very sensitive to both viruses and bacteria and often die in unfavorable weather. Melons are often affected by root rot. With this disease, the stems become thinner, their lower part turns brown, the leaves turn yellow and wither, and the pulp begins to deteriorate. Dark spots inside the melon quickly increase in size. The disease is transmitted by seeds, so before planting they are placed in an aqueous solution of formaldehyde for 5 minutes.

White spot (septoria)

After cold and prolonged rains, light, round spots appear on the stems and leaves of the melon. The fungal infection is transmitted with seeds, gets in with plant debris and causes septoria. Mycelium spores spread quickly, the leaves of the crop darken. To prevent the disease, melon beds are sprayed with Bordeaux mixture.

Corner spot (bacteriosis)

During heat and high humidity, greasy brown stains appear on the melon stems, and cloudy drops form on the back of the leaves. Corner spot also affects the fruits, they become like glass, the skin of melons becomes sticky.

Ascochyta blight

In cold weather, which is combined with high humidity, the melon crop is affected by one of the most severe fungal diseases. With ascochyta blight, barely noticeable spots appear on the stems. They quickly increase in size, the root collar dries out, and ripening melons turn black and disappear.

Anthracnose (scarden)

If crop rotation is not observed, or frequent and abundant watering occurs, round pink spots appear on the leaves of the crop, in place of which holes form. With a melon disease such as anthracnose, the vines of the plant become thinner, break when touched, and over time the leaves curl into a tube and dry out. When infested with copperhead, the melon flesh will have brown spots that spread quickly and the fruit will rot.