Torymus myrtacearum

Torymus myrtacearum belongs to the order Hymenoptera, family Torymidae. It is a small insect that often leads a parasitic lifestyle.

Physically, the adult appears as a small wasp with a characteristic metallic sheen. Females have a long ovipositor, which allows them to penetrate inside plant tissues.

The larvae of this species have a whitish or cream color; they develop directly inside the fruits or galls formed by the host plant.

Identification of the adult in field conditions is difficult without the use of a microscope due to the small size of the insect, which usually does not exceed a few millimeters.

The main danger is posed not by the adults themselves, but by the larvae, which damage the internal structures of plant organs while feeding.

The primary objects of infestation are plants of the Myrtaceae family. The pest specializes in species that form fleshy fruits or specific tissue outgrowths.

The insect can cause significant damage to plantations where myrtle crops are grown, reducing both the market appearance and the biological value of the harvest.

Damage manifests as premature fruit drop and fruit deformation, which significantly reduces the yield of quality products.

During mass outbreaks, the pest can affect up to 60-80% of the crop, making it a serious threat to commercial horticulture in its distribution regions.

In addition to direct damage to fruits, larval activity inside the tissues promotes the entry of secondary infections that cause rot.

The development cycle is closely linked to the phenology of the host plant. The activation of insects usually coincides with the flowering period and the beginning of fruit set.

The overwintering stage of the pest most often occurs inside infested fruits or in the soil, depending on the specific environmental conditions of the population.

Adult emergence occurs in spring or early summer, when the air temperature becomes stable enough for mating and egg-laying.

One or two generations may develop per season, depending on the climatic factors of the region and the duration of the growing season.

The peak activity of the pest is observed during hot and humid months, which facilitate the rapid metamorphosis of the larvae.

The first sign of infestation is the appearance of small holes on the fruit surface, through which adults exit after completing their development cycle.

In early stages, fruits may appear normal, but upon dissection, cavities filled with larval waste products are found inside.

Mass dropping of immature fruits is observed, which look underdeveloped or have mottled coloration due to metabolic disturbances.

In some cases, galls can form on leaves or shoots near infested fruits, inside which the wasp larvae develop.

• Darkening of fruit tissues around the larval chambers.
• Presence of exit holes with a diameter of about 0.5–1 mm.
• Specific fruit deformation and uneven growth.

The main control method is sanitary pruning and destruction of infested fruits before the adults emerge, which breaks the pest's development cycle.

The use of biological protection methods, such as utilizing entomophages, limits the Torymus myrtacearum population density in the natural environment.

Chemical protection must be strictly regulated and carried out during periods when the insects are most vulnerable to contact insecticides.

An important element is the observance of agrotechnical practices aimed at increasing plant immunity and reducing environmental stress factors.

It is recommended to carry out monitoring using pheromone or colored sticky traps to determine the timing for protective measures.