by Nancy Power, Ph.D. Candidate
When I tell people that I work with wasps, their first question is, “Do they sting?” My wasps are tiny; about as big as a dash on your screen -. They do not sting people, but they do sting the eggs of stink bugs. The wasp probably injects a venom, because the bug egg always dies rather than hatching into a baby bug. The wasp also injects one of its eggs into the bug egg, leaving a tail sticking out. The wasp egg is not hurt by the venom, but instead hatches inside the bug egg, and the worm-like baby wasp eats the bug egg for food while it grows. Several days later, a cute little wasp head with antennae pokes out of the bug egg. The wasp chews a hole big enough to escape the egg, and a new wasp is born. Within a few days, it will be looking for bug eggs on which to lay its own eggs, and the circle of life will continue.
You might be wondering, “Why do I study this wasp?” A bunch of these wasps (Ooencyrtus mirus) were brought from far away Pakistan, a country in Asia, to test whether they might be able to help control a pest stink bug called the bagrada bug.
When I tell people that I work with wasps, their first question is, “Do they sting?” My wasps are tiny; about as big as a dash on your screen -. They do not sting people, but they do sting the eggs of stink bugs. The wasp probably injects a venom, because the bug egg always dies rather than hatching into a baby bug. The wasp also injects one of its eggs into the bug egg, leaving a tail sticking out. The wasp egg is not hurt by the venom, but instead hatches inside the bug egg, and the worm-like baby wasp eats the bug egg for food while it grows. Several days later, a cute little wasp head with antennae pokes out of the bug egg. The wasp chews a hole big enough to escape the egg, and a new wasp is born. Within a few days, it will be looking for bug eggs on which to lay its own eggs, and the circle of life will continue.
You might be wondering, “Why do I study this wasp?” A bunch of these wasps (Ooencyrtus mirus) were brought from far away Pakistan, a country in Asia, to test whether they might be able to help control a pest stink bug called the bagrada bug.
Bagrada bugs are also from Asia, but they made their way to California in 2008, probably on a container ship. We don’t know how many came at first, or whether they came as eggs, baby bugs or adults. Once off the ship, they probably found some mustard weed plants to eat. Then they had babies. Lots of babies. The babies grew into adults. The adults can fly, so when the mustard dried out at the end of the summer, they flew to sweet alyssum plants in someone’s yard, and eventually made it to irrigated fields of broccoli, cabbage or cauliflower. They had lots more babies, who grew up within a few weeks and had lots more babies, who grew up within a few weeks and had lots more babies. Before you know it, there were a LOT of bagrada bugs and they were a BIG pest on broccoli crops. They ate so much of the baby plants, or “seedlings,” that some of the seedlings died, and other plants never grew broccoli heads, or were so deformed that the broccoli could not be sold. The farmers were not happy! They were losing money. They tried a lot of things to control the bugs, like planting broccoli seedlings instead of seeds, putting nets over the plants, and even vacuuming the bugs, but the only thing that worked well and was affordable was to spray the crops with insecticide to kill the bagrada bugs. That worked!
Insecticides, though, have their own problems. First of all, organic farmers may not use most of them. Also, insecticides are not cheap. And they can be poisonous to farm workers. Furthermore, they can have bad side effects, like killing the “good” insects that eat the “bad” insects, and poisoning flower-visiting insects like honey bees and native bees.
That is where my wasp comes in. If it proves to be a good control agent, I can ask the federal government for a permit to release a number of them in farmers' fields. The wasps might be able to control the bagrada bug by themselves, giving farmers a new option. The wasps could have babies in the fields, so we would not have to keep releasing new wasps each year. The farmers would save money on insecticides, the farm workers would not be at risk from poisons, the “good” insects would be spared, and the bees would be safe.
In the meantime, I have to study the wasps in a prison-like building called “Quarantine.” An “insect jail,” it is meant to keep insects in, unless and until they get approved to be released. Inside quarantine, I do experiments to find out if my tiny wasps will attack the “good” native bugs. If they do attack native bugs, they might become a pest themselves if they were to be released. I also have to check to see if they can have babies at least as fast as the bagrada bug has babies, to see if the wasps have the potential to control the bug population. Another experiment tests what temperature is best for rearing the wasp.
Insecticides, though, have their own problems. First of all, organic farmers may not use most of them. Also, insecticides are not cheap. And they can be poisonous to farm workers. Furthermore, they can have bad side effects, like killing the “good” insects that eat the “bad” insects, and poisoning flower-visiting insects like honey bees and native bees.
That is where my wasp comes in. If it proves to be a good control agent, I can ask the federal government for a permit to release a number of them in farmers' fields. The wasps might be able to control the bagrada bug by themselves, giving farmers a new option. The wasps could have babies in the fields, so we would not have to keep releasing new wasps each year. The farmers would save money on insecticides, the farm workers would not be at risk from poisons, the “good” insects would be spared, and the bees would be safe.
In the meantime, I have to study the wasps in a prison-like building called “Quarantine.” An “insect jail,” it is meant to keep insects in, unless and until they get approved to be released. Inside quarantine, I do experiments to find out if my tiny wasps will attack the “good” native bugs. If they do attack native bugs, they might become a pest themselves if they were to be released. I also have to check to see if they can have babies at least as fast as the bagrada bug has babies, to see if the wasps have the potential to control the bug population. Another experiment tests what temperature is best for rearing the wasp.
I know this sounds weird, but I love my wasp species. If you wonder how anyone could love a wasp, read my next blog post, “It’s a girl!” (link to post).