A new study has found that lizards that eat fire ants – a venomous, invasive pest found in many parts of the world – could gain a measure of protection against their stinging bites.
The lizards may be able to digest and process the ants’ venom and become more immune to it. It is akin to a ant venom vaccine. This means that native species can adapt to defend themselves against invaders. It allows them to coexist and not be destroyed by changing ecology.
“We know that fire ants-infested lizards have different immune profiles to lizards living in non-fire ant areas.” says biologist Tracy LangkildePenn State.
“Because our immune system is so important for survival, we wanted a way to determine if these immune profiles could be directly attributed lizards being stung frequently by fire ants or eating fire ants.”
The study was performed on eastern fence-lizards (Sceloporus undulatus), which are native to the eastern US. Fire ants (Solenopsis Invicta() are a native South American pest and considered an invasive species in the US. Their bites can trigger an immune response in a variety of species.
Fire ant venom can prove fatal to eastern fence-lizards if given in sufficient quantities.
Scientists noticed that the ants were present in the same range of lizards’ habitats for 70 years. They conducted a study in which they exposed these “naive” animals to fire ant poison.
Three weeks ago, one group (17 lizards) was given fire ants (the Fed Group), while another group (18 lizards) were bitten three times per week by fire ants. The lizards were tested for six types of immune responses after the three-week period was over.
“We conducted a comprehensive assessment of most branches of the immune system, including measures of the innate immune system – resources that an individual is born with – and the adaptive immune system, which develops immune resources after exposure to a foreign substance like an infection or vaccine,” SaysCatherine Tylan, a Penn State biologist, was the one who conducted the research.
“This allowed us see how different immune responses to fire ant exposure are allocated.”
The Fed lizards had three higher immune measures than the Stung group. A type of white cell they had an increase in was called BasophilsThis is responsible for the immune response’s inflammatory reactions; an increase in immunoglobulin Antibody(IgM) is a known fire ant venom responder; an increase in Complementactivation, which aids the body’s immune system.
Tynan notes that all three of these responses could help the lizard’s immune defense against fire ant poison.
“For example, fire ant-specific antibodiesComplement could be used to bind up venom, so that it doesn’t have a negative impact on the body.” She says. “It is possible that fire ant poison from consumed fire ants triggers an immune response. It acts somewhat like a vaccine. In this way, eating fire ants could help lizards prepare to be stung in the future.
Researchers compared Fed lizards to wild lizards that live in areas with fire ant infestations. The results revealed several similarities in immune profiles when comparing them against naive ones. The differences in IgM counts for fire ant-specific IgM were especially evident across both groups. This suggests that the markers may be related to eating fire ants.
There were also some differences. Researchers suggested that field lizards may have some immune responses to stress from fire ant encounters. You could even find something that has nothing whatsoever to do with fire-ants.
The immune profile of fire ants is altered by fire ants. This information can be used to help native species adapt to changing ecological conditions.
The researchers found that there are potential protective effects from sub-lethal ingestion of poisonous/venomous invasives species. Send them a note in your paper“May allow native peoples to survive and coexist alongside these otherwise deadly invaders.”
The research was published in Biological Invasions.
