Cuticular Hydrocarbon Cues Are Used for Host Acceptance by Pseudacteon spp. Phorid Flies that Attack Azteca sericeasur Ants

Abstract

Parasitoids often use complex cues to identify suitable hosts in their environment. Phorid fly parasitoids that develop on one or a few host species often use multiple cues, ranging from general to highly specific, to home in on an appropriate host. Here, we describe the hierarchy of cues that Pseudacteon phorid flies use to identify Azteca ant hosts. We show, through behavioral observations in the field, that phorid flies are attracted to two cryptic Azteca species, but only attack Azteca sericeasur (Hymenoptera: Formicidae: Dolichoderinae). To test whether the phorid flies use cuticular hydrocarbons (CHCs) to distinguish between the two Azteca taxa, we first documented and compared cuticular hydrocarbons of the two Azteca taxa using gas chromatography/mass spectrometry. Then, using cuticular hydrocarbon-transfer experiments with live ants, we characterized the cuticular hydrocarbons of A. sericeasur as a short-range, host location cue used by P. lasciniosus (Diptera: Phoridae) to locate the ants.

The Community Ecology of Herbivore Regulation in an Agroecosystem: Lessons from Complex Systems

“…Phorids attacking, " and the surrounding sisters all adopt a sort of catatonic posture, heads up, mandibles open, and stationary (figure 6b; Liere and Larsen 2010, . Although the phorid is able to detect the alarm pheromones of the ant and is therefore attracted to it, it is unable to actually oviposit on the ant unless it sees some movement (Mathis et al 2011, Mathis and Philpott 2012, Mathis and Tsutsui 2016. Therefore, not only the ant under potential phorid attack, but also the sisters surrounding her assume this semistationary posture, a result of the very specific pheromone that alerts all ants in the vicinity that a phorid is lurking about.…”

Interspecific Eavesdropping on Ant Chemical Communication

“…Straight-chain and cyclic ketones (e.g., 2-heptanone and 2-methylcyclopentanone, respectively) act as alarm pheromones attracting nearby nestmates (Wheeler et al, 1975;McCann et al, 2013) while volatile aldehydes and iridoids (e.g., nepetalactol, iridoidal isomers) may simultaneously signal nest location (Adams, 1994;Nascimento et al, 1998). Less volatile chemicals such as cuticular hydrocarbons provide short-range information that allows parasitoids to discriminate between species (Mathis and Tsutsui, 2016). (A) A phorid fly hovers outside Azteca nest, attracted by alarm pheromones.…”

“…Phorid flies are most often specialists, attacking a single host ant species (Porter, 1998;Weissflog et al, 2008;Witte et al, 2010;Folgarait, 2013) but the chemical attractants of phorids may be more indiscriminate for long-range host localization. Once the fly has entered the habitat and found the nest or trail, they appear to use species-specific hydrocarbons to ensure species specificity (Mathis and Tsutsui, 2016). Phorids are recorded as the most-commonly observed associates among army ant bivouacs, raid trails, and refuse piles (Rettenmeyer and Akre, 1968).…”

Ant–hemipteran association decreases parasitism of Phenacoccus solenopsis by endoparasitoid Aenasius bambawalei

“…For simulated association treatment, each cotton plant was infected by 60 mealybugs, and 10 dried ghost ants were pinned on the plants as if tending the mealybugs and walking nearby. The ghost ant workers were eluted by hexane and dried according to the method described by Mathis and Tsutsui (), and then used in simulated association as described earlier. On the control plant, only mealybugs were transferred to the plants with neither live nor dried ghost ants.…”

“…Chemical signals from freshly damaged plants are attractive to the egg parasitoid Trichogramma pretiosum (Peñaflor et al, 2011). Phorid fly parasitoids Pseudacteon lasciniosus can use the cuticular hydrocarbons of ants as a short-range olfactory cue (Mathis & Tsutsui, 2016). Braconid parasitoids take advantage of herbivore-induced plant volatiles and pheromones in combination to locate their mates (Xu et al, 2017).…”