# Considerations on the Life Cycle of Laminosioptes cysticola (Vizioli, 1870) Based on a Natural Infestation in Two Laying Hens

## TL;DR

This paper describes the life cycle of a rare mite, Laminosioptes cysticola, found in two hens, based on observations and literature review.

## Contribution

The paper proposes a hypothetical life cycle for Laminosioptes cysticola based on new observations and existing literature.

## Key findings

- Adult mites were found in subcutaneous tissue and on internal organ serosal surfaces.
- Larval and nymphal forms were observed near the trachea and esophagus, suggesting migration patterns.
- A granulomatous reaction leads to calcified nodules as mites degenerate in subcutaneous tissue.

## Abstract

In two adult hens from a rural farm, an infestation by Laminosioptes cysticola was diagnosed by necropsy and parasitological examination. It is a mite that colonizes the subcutaneous tissue and various visceral serosal surfaces, causing the formation of small nodules that tend to calcify over time. This is a relatively unknown parasite, whose biological cycle is still not exactly known. For this reason, by combining our observations—derived from the meticulous parasitological examination of the parasites present in various anatomical regions—with the information present in the literature, we have hypothesized a possible life cycle, highlighting the entry point in the subcutaneous tissue, the migrations carried out by the immature and adult forms, and the possible methods of diffusion within the farm.

Laminosioptes cysticola (Vizioli, 1870), a tissue-dwelling mite responsible for nodular acariasis in birds, was identified from two hens reared in a rural backyard flock in Umbria, Italy. Adult mites were found in the subcutaneous tissue and on the serosal surface of various internal organs. Larval and first- and second-stage nymphal forms were observed beneath the skin and near the trachea and esophageal serosa. By comparing the existing literature with that reported in the present study, we propose a hypothetical reconstruction of the parasite’s life cycle. It is postulated that the entry of L. cysticola occurs through the cervical skin, where adults mate and larviparous females give birth to larvae. These larvae migrate into the loose connective tissues surrounding the trachea and esophagus, where they develop into nymphs. The immature forms then progress along the esophagus and trachea to reach the thoracic and abdominal cavities, colonizing the serosal surfaces of visceral organs. It remains unclear whether, or how, the mites return to the subcutaneous tissues to complete their maturation. Senescent specimens degenerate within the subcutis, where they are encased by a granulomatous inflammatory reaction that leads to the formation of characteristic calcified nodules.