Search

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. [ABSTRACT FROM AUTHOR]

Hosts of tephritids are known to vary in their capacity to support the life cycle from egg lay to adult. The Host Reproduction Number (HRN) is a measure of this capability and is defined as the number of adults that emerge from one kg of fruit. We collected data from the literature covering 26 New World fruit fly species in the genera, Anastrepha, Bactrocera, Ceratitis and Rhagoletis, on > 350 plant hosts. We provide the HRN where possible but only about 13% of tephritid-host data had HRN figures. More research is required to better understand the risks posed by New World tephritid-host relationships. For the tephritids of the world, there is a need to develop an appendix to ISPM 37 or new ISPM for each tephritid covering different hosts in different countries because one HRN does not fit all situations. A more country-based HRN will help to better inform and triage hosts for targeted surveillance programs, pest management and incursion response. Also, HRN would inform disinfestation activities associated with market access protocols. Therefore, a more HRN informed world will be better able to feed a growing world population using optimised risk management and trade. [ABSTRACT FROM AUTHOR]

Hosts of tephritids are known to vary in their capacity to support the life cycle from egg lay to adult. This capability is measured by the Host Reproduction Number (HRN) which the number of adults that emerge from one kg of fruit. Mediterranean fruit fly (Medfly) is one of the economically important fruit flies and is distributed worldwide. Many Medfly hosts are known but data to quantify their capacity to support the life cycle is scattered through many reports. Here, we reviewed published literature and found data on 146 potential hosts. We placed them in order of HRN and their Host Suitability Index. The HRN values ranged from bird plum (HRN = 1019) to three species of Syzygium which were non hosts (HRN = 0). The HRN order will help to inform and triage hosts for targeted surveillance and eradication programs and inform disinfestation activities associated with incursion response management, and for trade and risk mitigation. [ABSTRACT FROM AUTHOR]

Tramps ants are a constant biosecurity threat to Australia. Red Imported Fire Ant Solenopsis invicta was detected in Sydney, New South Wales in 2014, and a successful eradication program was undertaken. Stratified surveillance was conducted as part the program, and allowed for scenario tree analysis to statistically support the claim of freedom. Our analysis demonstrated a mean probability of freedom was 93.1%, 99.5% and > 99.9% after one, two or three surveys for two nests within 2 km of the detection. We demonstrated > 99.9% probability of freedom after three surveys if for a threshold value of five nests were present. Our analysis was the basis of declaring Sydney free from S. invicta. Sydney was declared free 18 months after the first detection of S. invicta. [ABSTRACT FROM AUTHOR]