The Nose Knows: How Wasps Find Their Targets

Parasitoid wasps are like tiny detectives. They can find their prey in a crowded, smelly world. This is thanks to their super-powered sense of smell. Scientists have been studying a specific type of wasp called Microplitis mediator. They wanted to understand how these wasps use their sense of smell to find their hosts. First, they looked at the wasp's genes. They found 177 special genes that help the wasp smell. These genes are called odorant receptors, or ORs for short. ORs are like tiny antennas that pick up smells from the environment. The scientists found 75 new ORs that hadn't been documented before. This is a big deal because it means we now know more about how these wasps smell than ever before. The scientists also compared these ORs to those of another wasp, Microplitis demolitor. They found that many of the ORs were very similar. This suggests that these wasps might use their sense of smell in similar ways. The structure of these OR genes is also very similar within the same group. This means that these genes have been conserved over time, which is a sign that they are important for the wasp's survival. But how do these ORs work? The scientists found that most of these ORs are found in the wasp's antennae. This makes sense because the antennae are the wasp's primary smell detectors. However, some ORs were found in other parts of the body. This suggests that these ORs might have other functions besides smelling. Interestingly, the scientists found that some ORs are more active in female wasps, while others are more active in males. This could mean that females and males use their sense of smell in different ways. For example, female wasps might use their sense of smell to find hosts to lay their eggs in, while males might use it to find mates. This study is important because it helps us understand how parasitoid wasps use their sense of smell to find their hosts. This knowledge could be used to help control pest populations naturally, without the use of harmful pesticides. It's a win-win for both the wasps and the environment.