Incursions by exotic tephritids continue to threaten Australia. Host suitability for a specific tephritid is ranked by the number of adults which can emerge from one kg of fruit or the Host Reproduction Number (HRN). Bactrocera dorsalis has previously invaded northern Australia but was eradicated. However, Bactrocera dorsalis remains the largest exotic threat and is likely to invade through northern Australia but B. tryoni and other tephritids are already well established. One question is what hosts would likely provide the best early warning for an exotic incursion. Here, the HRN for 40 hosts for Bactrocera dorsalis and B. tryoni were established from the scientific literature. The reproductive advantages of one species over the other were calculated by dividing the higher HRN by the lower HRN. The fruits with the highest reproductive advantage (> 30) favouring B. dorsalis were soursop, mango and capsicum. The reproductive advantage estimate was compared to surveillance data collected during B. dorsalis eradication in north Queensland from 1995 to 1997. Mangoes and capsicum were among the mostly commonly infested hosts. Capsicums provided the second highest number of samples and would seem ideal candidates as sentinel plants for current surveillance programs. Some inconsistencies are identified and discussed. The HRN and reproductive advantage may have the potential to identify hosts and industries for early warning exotic fruit fly surveillance, better-targeted eradication programs and risk assessments for imports/exports.

外来实蝇的入侵继续威胁着澳大利亚。特定实蝇的寄主适宜性按照一公斤水果中可产生的成虫数量或寄主繁殖数 (HRN) 进行排名。橘小实蝇（Bactrocera dorsalis）此前曾入侵澳大利亚北部，但已被根除。然而，橘小实蝇（Bactrocera dorsalis）仍然是最大的外来威胁，并可能入侵澳大利亚北部，但B.tryoni和其他实蝇已经广泛存在。一个问题是，什么样的宿主可能会为外来入侵提供最佳的预警。此处，根据科学文献建立了40 个橘小实蝇(Bactrocera dorsalis)和B.tryoni宿主的 HRN 。一个物种相对于另一物种的繁殖优势是通过将较高的 HRN 除以较低的 HRN 来计算的。对桔小实蝇具有最高繁殖优势（> 30）的水果是刺果番荔枝、芒果和辣椒。将繁殖优势估计值与1995 年至 1997 年昆士兰北部消灭橘小实蝇期间收集的监测数据进行了比较。芒果和辣椒是最常受感染的宿主。辣椒提供了第二多的样本，似乎是当前监测计划的哨兵植物的理想候选者。发现并讨论了一些不一致之处。 HRN 和繁殖优势可能有潜力识别寄主和产业，以进行早期预警外来果蝇监测、更有针对性的根除计划和进出口风险评估。