Flirting with danger: predation risk interacts with male condition to influence sexual display

Sexual signaling coevolves with the sensory systems of intended receivers; however, predators may be unintended receivers of sexual signals. Conspicuous aerial displays in some species may place males at high risk of predation from eavesdropping predators. There are three different hypotheses to explain how signaling males can deal with increased predation risk: (1) males invest in survival by decreasing signal conspicuousness; (2) males invest in reproduction by increasing signal conspicuousness; and (3) male response is condition-dependent according to his residual reproductive value. Here, we used blue-black grassquits (Volatinia jacarina) to test these hypotheses, asking whether males modify leap displays under different levels of predation risk. Grassquit males develop an iridescent nuptial plumage and spend considerable time emitting a multimodal signal: while leaping from a perch, males clap their wings above their heads and emit a high-pitched short song. We exposed males to predator and nonpredator playbacks while video recording their displays. We found interactions between predation risk and 2 male condition variables (ectoparasite infestation and proportion of nuptial plumage coverage) that influenced display behavior. Less parasitized males and those with higher proportion of nuptial plumage showed no change in display behavior, while more parasitized males and those with lower proportion of nuptial plumage increased the vigor of displays under predation risk. In other words, males with low residual reproductive value increased reproductive effort when there was a high risk of extrinsic death. Our study provides some empirical support for the terminal investment hypothesis.

On the wasp-mimicking sharpshooter genus Propetes Walker, 1851 (Hemiptera: Cicadellidae: Cicadellinae): description of a new species, proposal of a new synonymy, and distributional notes

The Neotropical genus Propetes Walker, 1851 currently includes three species recorded from Brazil and Guyana that share morphological characteristics related to wasp-mimicking behavior. A revision of available material of Amazonian Propetes was conducted, and a new species, P. sakakibara sp. nov., is described and illustrated herein based on males from Brazil, Peru, and Venezuela. Based on the association of males and females from Pará State (Brazil), a synonymy is proposed between P. triquetra (Fabricius, 1803) (previously known only from males) and P. compressa Walker, 1851 (previously known only from females). The female genitalia of P. triquetra is redescribed and illustrated in detail. Observation of bluffing display behavior is reported for the first time for the genus, in P. schmidti. A key to all species included in Propetes, based on males and females, and a map of distribution of Propetes species are provided, including new records of the genus from French Guiana, Peru, and Venezuela.