Everyone knows that lady beetles are awesome. But if you have somehow missed out on the lady beetle fan club until now, here’s your chance to get in on the lady beetle love. Asian lady beetles use “biological weapons” – parasite weapons. [Relevant] This is awesome enough that it made it into the May issue of Science. The story goes like this:
Asian lady beetles, aka Harlequin lady beetles, are the ones that you see all the time. They’re not native; we introduced them to control our agricultural pests. The problem is that the Asian lady beetle then turned into a pest, mostly because the arrival of this species caused declines in populations of native species of lady beetle. That’s sad, because there are some really, really cool lady beetles out there, and we don’t want them to go away.
What is it about these Asian lady beetles that causes the declines in the native species? One reason is that ALBs have symbiotic fungi. These are actually microspordian parasites, but it turns out that ALBs aren’t affected by the parasites (probably because ALBs have tons of antimicrobial peptides). However, the parasites are quite deadly to other, native lady beetle species.
How do the ALBs use their killer fungi on native species? BAZOOKAS. Ok, not really. It turns out that these fungi end up in the ALB eggs, and it just so happens that lady beetles tend to eat the eggs of competing species. So, a native lady beetle comes along, tries to wipe out some future ALB babies while simultaneously having an afternoon snack, and ends up getting infected by the fungus. Awe-some. Well, ok, not awesome, but you gotta hand it to the ALBs and their parasites.
Should we try taking antimicrobial peptides from ALBs and injecting them into native lady beetle species?
Vilcinskas, A., K. Stoecker, H. Schmidtberg, C. Rohrich, and H. Vogel. 2013. Invasive Harlequin ladybird carries biological weapons against native predators. Science 340(6134): 862-863.