When you take time to smell the flowers, or rather peer at the onions, you find some pretty cool stuff. This week, Simon shared with me another little gem of nature: parasitized natural enemies. Just a reminder, parasitoids develop internally on their host, usually killing it. This particular case of parasitism, however, is atypical in that the host does not die
Image courtesy of Maure et al. 2011
The victim of the story is the common Pink Lady Beetle, Coleomegilla maculata, affectionately called C-mac in some circles. C. maculata is a generalist predator, feeding on aphid species and other small soft bodied insects. I’m not surprised to see many of them in the onion fields. In this case, a parasitic wasp, Dinocampus coccinellae, lays a single egg inside its beetle host. Rather than killing the host, the wasp larva emerges and spins its pupal casing around the legs of the ladybug, keeping it in place. Thereby, providing its own bodyguard to protect it from predation and hyperparasitism (parasitoids that parasitize other parasitoids…that’s a lot of parasitism). This article was just published online about the system. Pretty cool!
Image courtesy of Stippen.nl
They’re coming. In fact, in places south of Ithaca they’re already here. Yep. They’re stink bugs.
Brown Marmorated Stink Bug
The Brown Marmorated Stink Bug (Halyomorpha halys, family Pentatomidae) is an introduced pest from Asia and has become a major pest of fruit and vegetable crops. In Pennsylvania, where the pest is believed to have been introduced, the apple and peach crops have suffered major losses. It’s really too bad if you want to make peach jam scones.
Appropriately named, stink bugs stink when you squish them. This is due to a chemical defense against predation. Imagine how that smell would taste… These bugs feed directly on fruit causing a type of damage known as catfacing. It’s spotty damage that renders fruit unmarketable. If these apples were growing on my tree, I’d probably just cut out the damaged parts and make applesauce or apple galette.
While stink bugs cause economic loss in the agricultural sector, most people encounter them in their homes. They often get in through cracks or open patio doors on a sunny day. I was in Pittsburgh last week, and stink bugs flew around the living room like nobody’s business. Not so fun when you’re Wii bowling and one flies into the side of your head at an alarming speed.
The brown marmorated stink bug is particularly pesky, and some other stink bugs in the family Pentatomidae are pests as well. But not all! There are, in fact, some beneficial species that are predators of caterpillar pests. Like this guy!
Spined soldier bug