TY - JOUR AU - Reid, Megan AU - Hill, Martin AU - Coetzee, Julie PY - 2023/05/18 Y2 - 2024/03/29 TI - Love at first bite? Pre-release surveys reveal a novel association between a native weevil and the invasive Nymphaea mexicana Zuccarini (Nymphaeaceae) in South Africa JF - African Entomology JA - Afr. Entomol. VL - 31 IS - SE - Articles DO - 10.17159/2254-8854/2023/a14949 UR - https://www.africanentomology.com/article/view/14949 SP - AB - <p>Classical biological control aims to suppress alien invasive plant populations by introducing host-specific natural enemies from the native range. This relies on the assumption that invasive plant populations in the invaded range benefit from the release of natural enemies. Pre-release surveys in the invaded range are a useful way to determine if enemy release applies to a particular invasive alien plant, and to determine what other factors may contribute to the invasion. Similarly, pre-release surveys gather information that can be used to compare invaded sites before and after the release of biological control agents and may also identify whether natural enemies have been accidentally introduced into the country. Pre-release surveys were conducted in South Africa on the invasive <em>Nymphaea mexicana </em>Zuccarini (Nymphaeaceae) to gather such information about this species, for which a biological control programme is being developed. There was lower diversity and abundance of herbivores in the native range compared to South Africa, suggesting that <em>N. mexicana</em> does experience enemy release at most sites in South Africa. This support for the enemy release hypothesis justifies the investment in biological control for its management. However, a native weevil, <em>Bagous longulus </em>Gyllenhal (Coleoptera: Curculionidae), was found feeding and reproducing on <em>N. mexicana </em>at three sites, resulting in damage to the leaves and suggesting that a novel association has formed between these species. <em>Bagous longulus </em>may have potential to be distributed to sites of <em>N. mexicana</em> where it is not present, though further investigation is necessary to confirm if its host range is suitable for this to be a safe endeavour. With the exception of sites where <em>B. longulus </em>was present, leaf sizes were large and damage was low, and there is no evidence that any natural enemies have been accidentally introduced from the native range. Findings such as these emphasise the importance of conducting thorough surveys during the development of biological control programmes.<span class="Apple-converted-space"> </span></p> ER -