Lesieur Vincent, Thomann Thierry, Jourdan Mireille, Kashefi Javid, Bon Marie-Claude
CSIRO European Laboratory, 830 Avenue du Campus Agropolis, 34980 Montferrier sur Lez, France.
European Biological Control Laboratory, USDA-ARS, 810 Avenue du Campus Agropolis, 34980 Montferrier sur Lez, France.
Insects. 2025 Mar 28;16(4):357. doi: 10.3390/insects16040357.
In classical biological control of weeds, the risk posed by a candidate agent to close relatives of the target weed in the intended area of release is a key criterion (i.e., candidate agents that demonstrate a high degree of host specificity). In this study, we investigated if the rosette crown-feeding fly Hennig (Diptera: Anthomyiidae) could meet this criterion and thus be considered a good candidate to control saffron thistle L. (Asteraceae: Cardueae) in Australia. Previous studies indicated that is specific to and did not infest the closely related crop, safflower ( L.). However, more recent field observations made in Greece reported that infested safflower in cultivated fields. To determine if is safe for release as a biocontrol agent, we re-examined the host range of by performing new host-specificity testing combined with field surveys carried out in the south of France during two consecutive years. We also investigated the species identity of the flies by comparing DNA sequences ( barcode region) of specimens collected in France from and L. with those from Greece collected from and Lam. Our analyses confirmed that French and Greek samples identified as belonged to the same species, while a second group of Greek samples matched , indicating two distinct species. Our results also demonstrated that has a wider host range than previously suggested. Laboratory testing indicated that , and are suitable for the development of . Field surveys also revealed that is part of the host range of the fly. Based on the results reported here, may have the potential to control both the target weed, and but it may also be a threat to safflower, . Further investigations to assess under what conditions attacks may help clarify the level of risk to Australian growers.
在杂草的经典生物防治中，候选生物防治剂对预定释放区域内目标杂草近缘种构成的风险是一个关键标准（即表现出高度寄主专一性的候选生物防治剂）。在本研究中，我们调查了莲座状冠部取食的蝇类Hennig（双翅目：花蝇科）是否能满足这一标准，从而被认为是澳大利亚控制藏红花蓟（Carthamus lanatus L.，菊科：菜蓟族）的良好候选生物防治剂。先前的研究表明，该蝇类对藏红花蓟具有专一性，不会侵染其近缘作物红花（Carthamus tinctorius L.）。然而，最近在希腊进行的实地观察报告称，该蝇类在耕地上侵染了红花。为了确定该蝇类作为生物防治剂释放是否安全，我们通过进行新的寄主专一性测试并结合连续两年在法国南部进行的实地调查，重新审视了其寄主范围。我们还通过比较从法国采集的藏红花蓟和C. lanatus标本以及从希腊采集的C. tinctorius和C. lanatus标本的DNA序列（条形码区域），研究了这些蝇类的物种身份。我们的分析证实，被鉴定为Hennig的法国和希腊样本属于同一物种，而另一组希腊样本与C. napi匹配，表明存在两个不同的物种。我们的结果还表明，该蝇类的寄主范围比先前认为的更广。实验室测试表明C. lanatus、C. tinctorius和C. palaestinus适合该蝇类的发育。实地调查还发现C. palaestinus是该蝇类寄主范围的一部分。基于此处报告的结果，该蝇类可能有潜力控制目标杂草C. lanatus和C. palaestinus，但也可能对红花C. tinctorius构成威胁。进一步调查评估该蝇类在何种条件下攻击C. tinctorius可能有助于阐明对澳大利亚种植者的风险程度。
