Kecskeméti Sándor, Erdei Anna Laura, Simon Janka, Kiss Balázs, Molnár Béla Péter
Department of Chemical Ecology, Centre for Agricultural Research, Plant Protection Institute, HUN-REN, Budapest, Hungary.
Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
Sci Rep. 2025 Apr 1;15(1):11070. doi: 10.1038/s41598-025-88677-y.
Host finding behaviour and host acceptance for oviposition is a rather complex process amongst insects; it is a major decision that will have a direct effect on the performance of offspring. It is not uncommon that herbivorous insects oviposit on unsuitable hosts. The level of insect-host specialisation correlates with the likelihood of mis-oviposition incidence; polyphagous herbivore insect species have a higher chance to lay eggs on unsuitable hosts compared to specialised monophagous ones. Over several seasons, large numbers of walnut husk fly adults were observed on the canopy and fruit of European quince. Males were engaging in behaviours like fighting, courting, mating, and guarding oviposition sites, while females copulated, oviposited, or rested. Oviposition marks were found on quince fruits, with unhatched eggs, chorions, and newly hatched maggots inside. Molecular identification confirmed the species as Rhagoletis completa. To investigate this unusual host interaction, electrophysiological recordings were conducted on the antennae and maxillary palpi of WHF adults using quince and walnut fruit and foliage volatiles. Behavioural experiments also explored any preference for quince. The results showed that WHF adults, especially females, exhibited a positive attraction to quince fruit volatiles, indicating that their peripheral detection of volatiles is not limited to host-specific compounds. Based on these findings, we conclude that WHF adults treated quince as a suitable host for oviposition in a natural condition.
在昆虫中，寄主寻找行为和对产卵寄主的接受是一个相当复杂的过程；这是一个将直接影响后代表现的重大决定。草食性昆虫在不合适的寄主上产卵的情况并不罕见。昆虫与寄主的专业化程度与误产卵发生率相关；与专一化的单食性昆虫相比，多食性草食性昆虫在不合适的寄主上产卵的机会更高。在几个季节里，在欧洲榅桲的树冠和果实上观察到大量核桃果小实蝇成虫。雄性表现出争斗、求偶、交配和守护产卵地点等行为，而雌性则进行交配、产卵或休息。在榅桲果实上发现了产卵痕迹，里面有未孵化的卵、卵壳和刚孵化的蛆。分子鉴定证实该物种为完全实蝇。为了研究这种不寻常的寄主相互作用，利用榅桲和核桃果实及叶片挥发物对核桃果小实蝇成虫的触角和下颚须进行了电生理记录。行为实验还探究了对榅桲的任何偏好。结果表明，核桃果小实蝇成虫，尤其是雌性，对榅桲果实挥发物表现出积极的吸引力，这表明它们对挥发物的外周检测不限于寄主特异性化合物。基于这些发现我们得出结论，在自然条件下，核桃果小实蝇成虫将榅桲视为合适的产卵寄主。
