of virus-like particles. VLPs are similar to viruses in their structure, but they don't carry any nucleic acid. For example, Venturia canescens (Ichneumonidea) and Leptopilina sp. (Figitidaea) produce VLPs. VLPs can be compared to PolyDNAvirus because they are secreted in the same way, and they both act to protect the larvae against the host's immune system. V. canescens-VLPs (VcVLP1, VcVLP2, VcNEP ...) are produced in the calyx cells before they go to the oviducts. Work in 2006 did not find their link to any viruses and assumed a cellular origin. More recent comparison links them to highly reshuffled domesticated Nudivirus sequences. This link produces the name Venturia canescens endogenous nudivirus (VcENV), an alphanudivirus closely related to NlENV found in Nilaparvata lugens. VLPs protect the Hymenoptera larvae locally, whereas polyDNAvirus can have a more global effect. VLPs allow the larvae to escape the immune system: the larva is not recognised as harmful by its host, or the immune cells can't interact with it thanks to the VLPs. Venturia canescens uses these instead of polydnaviruses because its ichnovirus has been deactivated. The wasp Leptopilina heterotoma secrete VLPs that are able to penetrate into the lamellocytes, thanks to specific receptors, and then modify the shape and surface properties of the lamellocytes so they become inefficient and the larvae are safe from encapsulation. The Leptopilina VLPs or mixed-strategy extracellular vesicles (MSEVs) contain some secretion systems. Their evolutionary picture is less clear, but a recently reported virus, L. boulardi Filamentous Virus (LbFV), shows significant similarities. Micro-RNA MicroRNA are small RNA fragments produced in the host cells thanks to a specific enzymatic mechanism. They promote viral RNA destruction. MicroRNA attach to viral-RNA because they are complementary. Then the complex is recognised by an enzyme that destroys it. This phenomenon is known as PTGS (for post transcriptional gene silencing) or RNAi (RNA interference.) It is interesting to consider the microRNA phenomenon in the polyDNAvirus context. Many hypotheses can be formulated: Braconidae carry nudivirus-related genes in their genome, so they may be able to produce microRNA against nudivirus, as an innate immunity. Wasps perhaps use microRNA to control the viral genes they carry. PolyDNAvirus can also use PTGS to interfere with the host's gene expression. PTGS is also used for organisms' development, using the same enzymes as antiviral gene silencing, so we can imagine that if the host uses PTGS against polyDNAvirus, perhaps it also affects its development.