Magnetic reconnection is a ubiquituous process in astrophysical plasmas, being at the origin of many eruptive phenomena, and typically inducing an important localized transfer of magnetic energy toward the acceleration of particles. The tearing instability can trigger several reconnection events along a same elongated current sheet, bringing even more complexity to the process.

Here, we study the tearing instability in a 2.5D hybrid-PIC simulation using the Hybride code, and with boundary conditions similar to the topology of a Mobius strip. We show that the energy conversion predominantly takes place during the non-linear stage of the instability, by evaluating the ion electric work rate and pressure-strain interaction terms. We show that at the X-points, the magnetic energy gets converted in similar amounts to heating and plasma jetting, and that overall, there is more heating within the magnetic islands than around the X-points. Moreover, the reconnection outflows present an important ion temperature anisotropy with T||>Tperp, which is sustained by the contraction of the magnetic islands. The firehose instability then eventually regulates the temperature anisotropy within the islands and participates to the energy conversion.