Antagonistic interactions between frogs and insects are generally well-documented. In typical predator–prey interactions, these taxa feed on one another at different life stages. Moreover, insects can function as disease vectors or as parasites of frogs, an example being myiasis-causing flies. However, certain antagonistic interactions between frogs and insects are poorly known, specifically interactions that are mediated by sensory cues such as sound or smell. Here, we report an unusual association between Hyloscirtus lindae (Hylidae) and moth flies (Diptera: Psychodidae, Sycoracinae).

On 26 September 2021, JC observed more than 50 individual moth flies (Sycorax sp) on one male H lindae in a high-elevation Andean cloud forest (around 3000 m above sea level) within Ecuador's Napo province. The male tree frog was actively calling from a Guadua bamboo, at 1.5 m above the ground, under a light rain, close to a small creek. Meanwhile, male and female moth flies interacted with each other on the frog while the frog was calling. This reproductive behavior, known as lekking, has been previously observed in moth flies of the island of Borneo in Southeast Asia, specifically upon frogs of the Bufonidae, Microhylidae, and Megophryidae families. Similarly, in Ecuador, male moth flies are suspected to congregate on frogs to locate female moth flies with which to mate. Sycorax moth flies have been documented forming leks on actively calling male frogs, who advertise their presence to conspecific females through acoustic vocalizations. One possible explanation for how moth flies locate male frogs is through eavesdropping of the male frog advertisement signal. However, no study has tested this behavior to date. It has been previously suggested that moth flies form leks on male frogs because it provides an opportunity for lekking female moth flies to partake of a blood meal after copulating; however, we did not observe feeding on this occasion.

青蛙和昆虫之间的对抗性相互作用通常都有详细记录。在典型的捕食者与被捕食者的相互作用中，这些类群在不同的生命阶段相互依赖。此外，昆虫可以作为疾病媒介或作为青蛙的寄生虫，例如引起蝇蛆病的苍蝇。然而，青蛙和昆虫之间的某些对抗性相互作用却鲜为人知，特别是由声音或气味等感官线索介导的相互作用。在这里，我们报告了Hyloscirtus lindae（Hylidae）和蛾蝇（双翅目：Psychodidae，Sycoracinae）之间的不寻常关联。

2021 年 9 月 26 日，JC在厄瓜多尔纳波省的高海拔安第斯云林（海拔约 3000 米）中观察到 50 多只蛾蝇 ( Sycorax sp) 栖息在一只雄性H lindae身上。下着小雨，靠近小溪的雄性树蛙在距地面 1.5 m 的瓜杜亚竹上活跃地叫着。与此同时，当青蛙叫时，雄性和雌性蛾蝇在青蛙身上相互作用。这种被称为“lekking”的繁殖行为此前曾在东南亚婆罗洲岛的飞蛾中观察到，特别是在蟾蜍科、小蛙科和巨蛙科的青蛙上。同样，在厄瓜多尔，雄性飞蛾被怀疑聚集在青蛙身上，寻找雌性飞蛾进行交配。据记载，梧桐蛾蝇在主动呼叫雄性青蛙时形成了leks，雄性青蛙通过声音向同种雌性青蛙宣告自己的存在。对于蛾蝇如何定位雄性青蛙的一种可能的解释是通过窃听雄性青蛙的广告信号。然而，迄今为止还没有研究测试过这种行为。此前有人认为，蛾蝇在雄性青蛙身上形成leks，因为它为雌性蛾蝇提供了在交配后吸收血粉的机会；然而，我们这次没有观察到进食。