2012 Annual Report
1a.Objectives (from AD-416):
1. Identify components of systems approaches that would be useful in implementation of such an approach for e.g. tomatoes based on selected scenarios when pests such as fruit flies are found to be present.
2. Quantify to the extent possible how the different components such as application of low-prevalence, or poor host status might be used to mitigate risk to an acceptable level. Determine if in-field and/or post harvest mitigations (i.e. inspection, sampling, packaging, etc) can lower infestations. Identify data gaps and provide research as needed to improve information.
3. Assess systems using probabilistic models and/or point and range estimates to quantify overall risk of establishment in the importing country.
1b.Approach (from AD-416):
Our approach will be to use tomatoes that are poor hosts of tephritid fruit flies as the crop/pest model and develop a proposed systems approach that might allow affected growers to move their product outside a quarantine area. We will establish the parameters and components of a systems approach which would mitigate the risk associated with the quarantine based on established biologically-based concepts such as low pest prevalence, poor-host status, and/or less than probit 9 regulatory treatments. Finally we will assess the system to determine if the mitigation measures as identified in the systems approach would sufficiently mitigate risk using models and data developed from this project. The specific outcomes of this project would be to provide regulatory groups and the industry with specific information on how this new risk mitigation method could work in practice.
The goal of the agreement is the development of systems approaches for crops resulting in fruit fly quarantines in the U.S., which contributes to Objective 4 of the in-house project.
Evaluations to determine the susceptibility of Mediterranean fruit fly and Oriental fruit fly to infest tomatoes of different ripeness stages are currently being conducted. Indeterminate, Beefsteak tomatoes that were already harvested were selected for ripeness stages according to the color classification requirement standards for grades of fresh tomatoes. Laboratory reared Mediterranean fruit flies and oriental fruit flies were obtained from the Pacific Basin Agricultural Research Center’s rearing facility in Hilo, Hawaii. Three ripeness stages which showed at least 30% pink or red color were tested (forced infestation). Tomatoes were placed in wooden, screened infestation cages together with a cohort of gravid, female fruit flies. After 24 hours the tomatoes were removed and placed individually in plastic holding buckets. Buckets were checked at 11, 14 and 18 days after infestation. Results have shown that both Medflies and oriental fruit flies were recovered from tomatoes with 30% or more pink or red coloring. Further studies will be conducted on susceptibility of tomatoes with 30% or less of pink or red coloring. Choice preference studies will also be conducted on tomatoes of different ripeness and tomatoes versus other host fruits.