# Effects of Owinema Bio-Preparation on Vermicomposting in Earthworm Ecological Boxes
## 1 Introduction
An important group of natural insecticides is preparations based on selected nematode strains of the family _Steinernematiae_ (over 61 species) and _Heterorhabtidae_ (over 14 species). These have become an alternative to many insecticides, especially in integrated crops [20]. For both of the above-mentioned groups, a significant role is played by larvae: for _Steinernematiae_, third-stage larvae, and for _Heterorhabdtidae_, second- and third-stage larvae. These larval stages contain symbiotic bacteria of the genus _Xenorabtus_ (inhibiting the intestinal vesicle of nematodes) or _Photorhudus_ (occurring in the intestine of nematodes), which kill potential hosts. Their development takes place in the hemocoel and tissues of the host. The invasive forms of nematodes, used in bio-preparations, are not able to live outside potential hosts, e.g., Sciaridae. That is why the preparations appear to be safe for other soil fauna. Entomopathogenic nematodes weaken the host immune system by releasing proteinases which destroy pathogens, and they become an adequate environment for the development of bacteria [21; 22]. The above-mentioned biological preparations containing live nematode larvae may be effective in reducing the number of Sciaridae in greenhouse crops and under laboratory conditions. Nevertheless, the use of insecticides reducing _Sciaridae_ (Dimilin 25 WP, Nomolt 250 SC, and Dar 2.5 GR), even at doses safe for the environment, had an effect on the second generation (F1) of compost earthworms _E. fetida_, that is, cocoons produced by the earthworms [7; 8]. The relationships between earthworms and nematodes need further studies. They may be based on a phenomenon called phoresy, that is, transportation of one organism by another to obtain food or shelter. Phoresy may contribute to the direct effect of earthworms on the spread of nematodes in the soil environment. This phenomenon was confirmed in studies by [PERSON] [23]. He showed that the presence of earthworms (_Aporrectodea caliginosa_ and _Lumbricus rubellus_) in the medium had a positive effect on spread of _S. fetiae_ nematodes in soil, as compared with medium without earthworms. [PERSON] et al. [24] also studied the phenomenon of phoresy between earthworms _E. fetida_ (mature and young) and nematodes _Steinerrema fetiiae_ from two strains (strain from ENTONEM and nematodes RIOJA) for 24 h and 48 h. Compost earthworms transported both nematode strains with varied efficacy, which was in the range of 20%-90%. Both young and mature earthworms _E. fetida_ more frequently transported the strain RIOJA via the intestine (about 83%-92% nematodes _S. feltiae_; there were 1 to 11 nematodes per earthworm). After passing through the earthworm intestine, the nematodes became less virulent toward the larvae of _Galleria mellonella_. Their number was often reduced, which could be caused by earthworm digestive enzymes and microbial activity, since numerous soil microorganisms (bacteria, protozoa, algae, fungi, or nematodes) are food for annelids. Similar results were obtained by [PERSON] et al. [25], who showed lower virulence of nematodes _Steinrenema caropaspase_ towards insect larvae (_G. mellonella_) after isolating them from young earthworms _Lumbricus terrestris_ and _Aporrectodea trapezoides_. The aim of the work undertaken here was to determine the influence of an Owinema bio-preparation on _E. fetida_ (rate of waste vermicomposting) and _Sciaridae_ larvae in \"earthworm ecological boxes\".