General Impact
Like other gall-forming eulophid wasps, eggs are inserted inside young leaf and stem tissue. The wasp larvae, which develop within plant tissue, induce the formation of galls in the leaflets and petioles. As the infestation progresses, leaves curl and appear deformed while petioles and shoots become swollen. After feeding is complete, larvae pupate within the leaf and stem tissue. After pupation within the galls, adult wasps emerge after cutting exit holes through to the outside. Heavily galled leaves and stems result in a loss of growth and vigour. According to Yang et al. (2004), severe infestations can cause defoliation and death of trees (Heu et al. 2006).
The Erythrina gall wasp infests Erythrina spp. of which there are approximately 110 around the world (mostly in tropical regions) (Kim Delvare and La Salle 2004). Erythrina spp. are also known as coral trees and have a variety of functions in different locations. In Taiwan they are highly associated with farming and fishing activities (Yang et al. 2004). As indicated by its Latin name "erythros" meaning red, its obvious red flowers have been used as a sign of the arrival of spring and as a working calendar by tribal peoples (Yang et al. 2004). Specifically, the blooming of its showy red flowers signal to the coastal people to begin their ceremonies for catching flying fish, and for another people (the Puyama people) to plant sweet potatoes (Yang et al. 2004).
In Hai‘i, Erythrina variegata is also known as tigers claw, Indian coral and wiliwili-haole and is a common landscape tree (Heu et al. 2006). The Erythrina gall wasp infests the coral trees, Erythrina variegata, E. crista-galli and the native E. sandwicensis (Heu et al. 2006). A tall, columnar variety of E. variegata, also known as tropic coral, tall erythrina or tall wiliwili is used in Hawaii as a windbreak for soil and water conservation and for planting around farmsteads (Rotar et al. 1986, in Heu et al. 2006). For a closer look at the threat posed by the erythrina gall wasp to the native Hawaii wiliwili, please see Wiliwili on Maui: threatened by the Erythrina gall wasp.
Location Specific Impacts:China 
Parasitism: Erythrina gall wasp (Quadrastichus erythrinae) has caused severe damage to Erythina species (Erythrina Gall Wasp 2006). Mauritius
Parasitism: Erythrina gall wasp (Quadrastichus erythrinae) has caused severe damage to Erythina species (Erythrina Gall Wasp 2006). The wasp achieved pest status (Kim, Delvare and La Salle 2004). Reunion (La Réunion)
Parasitism: Erythrina gall wasp (Quadrastichus erythrinae) has caused severe damage to Erythina species (Erythrina Gall Wasp 2006). The wasp has achieved pest status (Kim, Delvare and La Salle 2004). Singapore
Parasitism: Erythrina gall wasp (Quadrastichus erythrinae) has caused severe damage to Erythina species (Erythrina Gall Wasp 2006). The wasp has achieved pest status (Kim, Delvare and La Salle 2004). Taiwan
Other: Coral trees, Erythrina species are found throughout the tropical regions of the world. Several species are commonly distributed in Taiwan and are highly associated with farming and fishing activities. As indicated by its Latin name "erythros" meaning red, its obvious red flowers have been used as a sign of the arrival of spring and as a working calendar. Whenever the showy red flowers bloom coastal people of Kavarawan, a Pingpu tribe and the Yami/Tao tribe begin their ceremonies for catching flying fish (and it is also a sign for the Puyama people to plant sweet potatoes).
Parasitism: At present five species and a subspecies of coral trees have been recorded as suitable hosts. These are Erythrina variegate L., E variegata var. orientalis (L.) Merr., E. corallodendron L., E. cristagalli L., E. abyssinica Lam., and E. berteroana Urban. Hawaii (United States (USA))
Other: The native wiliwili is a species mentioned in the ancient creation chant (the kumulipo) and is used traditionally to craft surfboards, canoe outriggers and fish float nets. This ancient low dryland forest tree is at serious risk of being wiped out by the Erythrina gall wasp (Hurley 2005).
Reduction in native biodiversity: In Hawaii, Erythrina variegata commonly known as tigers claw, Indian coral and wiliwili-haole is a common landscape tree (Heu et al.. 2006). There is also a variegated form known as the sunshine tree. The native coral tree E. sandwicensis is known as native wiliwili (Heu et al.. 2006). According to one estimation 10 000 to 20 000 wiliwili grow on southern Haleakala, all of which may be potentially at risk due to the spread of the Erythrina gall wasp (Hurley 2005).
In Hawaii the gall wasp infests the coral trees (Erythina spp.), in particular Erythrina variegata L., E. crista-galli L., and the native E. sandwicensis Degener (Heu et al. 2006). A tall, columnar variety of E. variegata known as tropic coral, tall erythrina or tall wiliwili is used in Hawaii as a windbreak for soil and water conservation and for planting around farmsteads (Rotar et al.. 1986, in Heu et al.. 2006).
|
