Life history and ecology Hylobius transversovittatus is a root-boring weevil. Field observations of adults are difficult since the weevils are predominantly nocturnal. In the spring, oviposition begins approximately 2 weeks after adults emerge from overwintering.
Females lay white, oval-shaped eggs into plant stems or into the soil close to the host plant.
The weevil occurs in all purple loosestrife habitats, except for permanently flooded sites. Experiments have shown that adults and larvae can survive extended submergence depending on temperature. However, excessive flooding prevents access to plants by adults and will eventually kill developing larvae. Aside from this restriction, the species appears quite tolerant to a wide range of environmental conditions. H. transversovittatus occurs throughout the native range of L. salicaria from southern Finland to the Mediterranean and from western Europe through Asia.