The transmission of ascoviruses is unusual in that they are poorly infectious per os and appear to be transmitted among lepidopteran hosts by parasite wasp vectors at oviposition [7, 43] . The genome of the ascoviruses can be replicated in presence of polydnavirus DNA either within the reproductive tissues of female wasps or within the body of the parasitized hosts infected by both polydnavirus and ascovirus. Consequently, integrated sequences of ascovirus origin can be expected within wasp and polydnavirus genomes. Reciprocally, sequences of polydnavirus origin may have been integrated in ascovirus genomes, whatever the wasp origin, ichneumonid or braconid. One gene family related to a bacterial family of N-acetyl-L-glutamate 5-phosphotransferase (Acc. N° of the closest bacterial relatives YP_001354925, CAM32558, ZP_00944224, ZP_02006449), identified only within the SfAV1a, HvAV3e and TnAV2c genomes, supports this conclusion. It has been found in the genome of a bracovirus, Cotesia congregata BracoVirus (CcBV [13] ; Fig. 4 ). Since this gene is absent in the genome of Microplitis demolitor BV, a related bracovirus [8] , it is difficult to infer the direction of the lateral transfer between the common ancestors of the three ascoviruses and of the wasp C. congregata. However, they unambiguously indicate that there was at least one lateral transfer for this gene between the common ancestor of ascoviruses and the parasitic wasp.