This article presents data about the extensity and intensity of infestation earthworms by larvae of metastronhils at farms, producing pork, on Polissya and Lisostep zones of Ukraine, which are disadvantaged about metastronhilosis.
It was studied the species composition and degree of damage of earthworms of various kinds – both on pig farms and pastures.

As we know from literary sources, metastronhilosis infestation is widely spread at pig farms in Ukraine. Economic losses from infestations consist of animal deaths, pork shortfall due to stunted growth of young, weight loss of adult pigs (for 25–33 %). The death of animals in disadvantaged farms ranges from 8–30 till 100 %.

The development process of metastronhilosis pathogens involving intermediate hosts – various species of earthworms. Аuthors published data from Belarus, Lithuania, Latvia, the Russian Federation and Azerbaijan were analyzed. They talk about a significant degree of infestation by metastronhils’ larvae in earthworms of different species.

The study was conducted in five farms, which are producing pork, disadvantaged about metastronhilosis, in Zhytomyr, Chernihiv and Kyiv regions. Lyumbrytsyds’ collection was performed by the method of I.I. Malevich from soil, manure and organic residues of pig farms, pig farms’ areas, fields and pastures. With each piece was selected from 95 till 240 worms – in general 2970 specimens (22 samples). The generic and species belonging of lyumbrytsyds we determined by microscopic studies.

For determination of seasonal dynamics of earthworms’ extensity of infestation by metastronhil larvae, we, from April to September, monthly collected and examined 550 earthworms. During the period of research we studied 3300 specimens. For determination of intensity of infestation we mounted the esophagus, crop and gizzard of earthworms, pressed between compressorium glasses. If metastronhils were found, they were counted.

In the pig farms which have been investigated, at Polissya and Lisostep zones of Ukraine, in soil, manure, organic debris of pig farms, pig farms’ area, fields and pastures, we found earthworms by family Lumbricidae of five species: Allolobophora caliginosa, Bimastus tenuis, Eisenia foetida, Eisenia rosea and Lumbricus rubellus.

Metastronhil larvae found in 1244 lyumbrytsyd of 2.970 specimens, which were collected from these locations. Thus, the extensity of invasion was 41.89 % with the intensity of infestation 20.9±5.8 specimens. Worms infested related to 4 species.

It is important to note that it was a relatively high intensity of infestation lyumbrytsyds species Allolobophora caliginosa – 26.3±9.2 specimens larvae (with extensity of infestation 26.23 %). Extensity of Bimastus tenuis’ invasion was 42.21 % with the intensity of infestation 13.7±2.0 specimens.

Worms Eisenia foetida were infested by metastronhils’larvae with extensity 56.15 % and intensity of infestation 25.3±4.8 specimens. In Lumbricus rubellus’ individuals found larvae of pathogens with extensity of infestation 23.45 %, with the intensity of infestation 14.9±5.6 specimens. Researched lyumbrytsyds of Eisenia rosea species were free from metastronhils’ larvae.

Most at all maggots had infested by metastronhils were worms which are living under in wooden floor and in it’s slit (extensity of invasion – 62.59 % with intensity of infestation 22.3±2.4 specimens).

Middle level of contamination on pastures was 33.75 % with the intensity of infestation 40.7±13.4 specimens, on detachments for walking the extensity of invasion – 29.93 % with the intensity of infestation 19.7±2.9 specimens, at the pig farms territory – extensity of invasion 26.87 % with the intensity of infestation 14.0±2.2 specimens.

We also noted the different levels of destruction by metastronhils’ larvae of earthworms different species, depending on place of their collection. Higher levels of infection noted in lyumbrytsyds, which lived in a pigsty (extensity of invasion – 62.59 % with the intensity of infestation 22.3±2.4 larvae’ specimens).

The most infested were worms of species Eisenia foetida (extensity of invasion – 70.34 % with the intensity of infestation 28.3±2.8 larvae’ specimens) and from pasture – Allolobophora caliginosa (extensity of invasion – 72.0 % with the intensity of infestation 48.4±5.9 larvae’ specimens).

In conclusion, we have to say, that results of determining of extensity and intensity of infestation earthworms by metastronhils’ larvae from April till September showed unexpressed dynamics of these indicators in the warm season. The difference in the level of contamination of earthworms by metastronhils’ larvae in different months of studies was not statistically significant (p>0.05).

For small rise extensity and intensity of infestation in September could, in our view, provide that in the warm season there is some accumulation of metastronhils’ larvae in the earthworms’ body.

So, as a result of investigations established that the biggest indices of metostronhils’ larvae’ extensity and intensity of infestation, are characteristic of worms, which are living under the wooden floor and pig farms in its crevices. We revealed that the most common intermediate hosts of metastronhils in Polissya and Lisostep zones of Ukraine are earthworms from Lumbricidae family: Eisenia foetida, Bimastus tenuis, Allolobophora caliginosa and Lumbricus rubellus.

Key words: lyumbritsydes, metastronhilosis, intermediate hosts, extensity of infestation, intensity of infestation, Eisenia foetida, Eisenia rosea, Allolobophora caliginosa, Bimastus tenuis, Lumbricus rubellus, Lumbricus terrestris.