[3] The mandibles of the larvae are unable to chew or digest food and are instead used to aid in movement and anchoring within the host.

Pseudacteon tricuspis is widely distributed around Argentina, Brazil, and other parts of South America, Europe, and Asia.

[2] Since its introduction to the United States, the species can be found across the country, but is concentrated along the south east parts, including Florida, Alabama, Arkansas, and Louisiana.

[4] The fly hatches from the egg in the first instar and will usually shed their serosa within 24 hours, although the process has been recorded to last up to 20 days.

During this time, the host fire ant appears and behaves normally because the parasitoid fly does not consume tissue.

The third instar will then release an enzyme or hormone that will loosen and decapitate the head of the host ant, which the fly then eats and resides inside.

While its purpose is not completely clear, it is thought to detect female odors, such as sex pheromones, during mate search.

[5] The fly exhibits attacking behavior towards the Solenopsis invicta fire ant when attempting to oviposit.

The fly will avoid attempting to oviposit in the alates of the colony and will instead exclusively attack worker ants.

[3] The daily activity of the P. tricuspis fly starts very low in the early morning, increases gradually, then peaks at midday.

In terms of seasonal activity, the fly population is seen throughout the year, but is highest in the fall and summer and lowest in the winter and spring.

This correlates to a density dependent response to the availability of the fire ant host, which is greater in the fall due to the frequent rainfall.

[2] Imported red fire ant Solenopsis invicta was accidentally introduced into the United States in Alabama in the 1930s.

The ants are extremely detrimental to the environment of the United States, costing around a billion dollars every year in damage and impacting native fauna and habitats.

[3] Additionally, in the presence of attack by P. tricuspis, the fire ant will typically reduce its foraging and resource retrieval rates significantly, by almost 84%.