So what makes Braconid (and Ichneumonid!) wasps so strange, and why am I writing about them on Biofortified?

Well, it turns out that Braconid and Ichneumonid wasps actually modify their hosts genetically by doing something which very much resembles gene therapy.

Most of the time we modify organisms because we want them to do something they currently don’t do. To use the example of BT corn, the corn plant was a better host for the European corn borer than we liked, so we took a protein from a bacteria which was known to kill the larvae which bored into the stalks but also known to be harmless to mammals and made the corn produce the protein which harmed the caterpillar and thus made a relatively bug-proof crop as far as the major pest was concerned.

Well, the caterpillars also produce genes which are bad for the wasps…these genes are involved in the immune system. The immune system’s role is to kill foreign invaders and if you fall under that category, you’re going to need a way to flout the immune system. The wasps in the video above accomplish this through a very strange symbiosis: they inject viral particles into the caterpillar to knock it’s immune system out.

These viruses are very strange because they contain very few viral genes. Many of the genes they contain are actually very similar to the immune system of the wasp. They don’t replicate, but they travel to certain points of the fat body and nervous system and begin producing proteins which have a great many functions, from increasing the amount of food the caterpillar consumes to producing proteins which interfere with immune functions.

It may seem odd to some that a blog that mostly focuses on controversies in modern agriculture would ask someone who studies insects to write on their site, but it’s not as counter intuitive as you think. Insects are a huge part of agriculture because they are our biggest competitors for food. One of the most common types of genetically modified corn, the various BT cultivars, were developed to fight the European Corn Borer, Ostrinia nubilalis, which is a tiny Crambid moth which burrows into the stalks of the plants and eventually kills them.

An entomologist writing for a site which explores the politics of Genetically Modified Organisms makes sense for another reason, and that’s because entomologists sometimes modify the genes of insects in order to do their work. Some of this occurs naturally, through the actions of polydnavirus particles some parasitoid wasps inject into their hosts to control the behavior, development, and immune reactions of that host. Sometimes it’s simple and artificial such as releasing insects sterilized with X-ray radiation in order to fight diseases and crop pests. Some of the things that entomologists work with aren’t necessarily insects but are used to control their populations. A great example of this is the modification of viruses as systems which are used to deliver pesticides directly to the insects rather than spraying the environment with pesticides.

What I hope to do is to use this site to educate the public about some of the GMOs you may hear about on the news, and I hope to make people realize that these are wonderful inventions that better humanity. New things are definitely a little scary at first, but education is the best way to overcome these fears.

Since this is my first post, let’s explore some really basic insect biology that might be necessary to understand parts of my posts. Insects go through two types of development: hemimetabolous, or incomplete metamorphosis and holometabolous which is commonly known as complete metamorphosis.

Here’s an example of hemimetabolous or incomplete development. The video below depicts the life cycle of a cicada which begins as an egg and then develops through a series of nymphal stages before maturing into an adult. Notice how the adults are very similar to the nymphs with the obvious exception of wings. Also notice how they have a relatively similar ecological role, both feed on sap but in slightly different areas.

This is an example of holometabolous development. The butterfly in the video has a very strange parasitic relationship with ants. This butterfly goes through four stages: egg, larva, pupa and adult. Notice how the larva looks nothing like the adult, and how the larva has a completely different role than the adult. In this case, the adult feeds on nectar from flowers while the larva is a parasite in the ant nest.