Trissolcus Basalis

Trissolcus Basalis Hatching

Picture Credited To Univeristy Of Hawaii At Manoa (http://www.ctahr.hawaii.edu/wrightm/images.html)

Trissolcus basalis is an invasive species that was intentionally introduced to Hawaii in order to control the overpopulation of the southern green stink bug, an agricultural pest (Johnson et al. 2005).  This non-native species parasitizes the eggs laid by female southern green stink bugs.  The attempt at managing the population size of the southern green stink bug using biological control was ultimately a success.  However, the discovery that Trissolcus basalis was a generalist egg predator meant big problems because it preyed on the eggs of other species with just as much frequency.  The inability to regulate this parasitism resulted in the classification of Trissolcus basalis as an invasive species.

Trissolcus basalis females parasitize stink bug eggs by inserting one of their own eggs inside the host’s egg.  Usually this invasive species will utilize 100% of the eggs in clutch laid down by the southern green stink bug (Johnson et al. 2005).  After hatching inside the host egg, the young Trissolcus basalis will remain in place as they continue to feed and mature.  Furthermore, Trissolcus basalis is known to parasitize adult stink bugs.  The non-native species will lay its eggs directly on the stink bug.  Once the young exit the egg, they bore a hole inside the adult stink bug and feed on them internally until development has been completely.  Interestingly, a study by Johnson and colleagues (2005) found that Trissolcus basalis was twice as likely to paracitize male stink bugs compared to female stink bugs on average (Johnson et al. 2005).   Male stink bugs are more vulnerable to this parasitic mechanism because Trissolcus basalis are able to attract individuals using deceptive pheromones.

Trissolcus Basalis Laying Eggs

Picture Credited To Univeristy Of Hawaii At Manoa (http://www.ctahr.hawaii.edu/wrightm/images.html)