Tiger pear biocontrol

Opuntia aurantiaca
Tiger pear

Tiger pear, along with all species of Opuntia cacti have been declared [Weeds of National Significance](http://www.environment.gov.au/cgi-bin/biodiversity/invasive/weeds/weeddetails.pl?taxon_id=82753) due to their invasive nature and negative impact on native flora and fauna. Tiger pear is drought resistant and found commonly in dry climates, riverbanks and pasture land. Tiger pear infestations pose danger to humans and animals as the cacti are covered in 25mm spines capable of causing injury. Three biocontrol agents have been released to control wheel cactus:

1. Cactoblastis Cactoblastis cactorum
2. Cochineal scale insect Dactylopius tapiacola
3. Stem-boring moth Tucumania tapiacola

The combined actions of these 3 biocontrol agents is expected to assist in the control and eventual eradication of tiger pear infestations in Australia. Of the three agents released, the cochineal scale insect and stem-boring moth have shown most promising results, while the cactoblastis has established on other preferred hosts and only feeds on tiger pear if its preferred common pear species are not present.

橙花仙人掌（Opuntia aurantiaca），又名虎梨仙人掌（Tiger pear）。

虎梨仙人掌与所有仙人掌属（Opuntia）物种均因入侵特性及对本土动植物的负面影响，被列为国家重要杂草（Weeds of National Significance），相关详情可参考：http://www.environment.gov.au/cgi-bin/biodiversity/invasive/weeds/weeddetails.pl?taxon_id=82753。

虎梨仙人掌耐旱性较强，常分布于干旱气候区域、河岸及牧场。其体表覆盖有25毫米长的尖刺，可造成机体损伤，因此该物种的入侵种群会对人类与动物构成安全威胁。

目前已释放三种生防因子以防控轮仙人掌（wheel cactus）：
1. 仙人掌螟（Cactoblastis cactorum）
2. 胭脂介壳虫（Dactylopius tapiacola）
3. 茎蛀蛾（Tucumania tapiacola）

上述三种生防因子的联合作用，有望助力澳大利亚境内虎梨仙人掌入侵种群的防控与最终根除。在已释放的三种生防因子中，胭脂介壳虫与茎蛀蛾已展现出最为可观的防控效果；而仙人掌螟已在其他偏好寄主上完成定殖，仅当该虫偏好的普通梨果仙人掌物种不存在时，才会取食虎梨仙人掌。