We recently shared a story about some problematic Crypts in a doctor’s office. We noted in the article that the occurrence of rogue beneficials was rare and that we had “one similar story.” Well, this is it. This time, though, it’s not Crypts hogging the limelight, but lacewings (Chrysoperla spp.) instead. Here’s what happened:
The Client
A long-time client, a major New York medical institute, approached us with a potentially tricky problem. They had mealybug-infested pothos being grown in TOPsider planter boxes placed between rows of booths in the institute’s open 24/7 cafeteria. The mealybugs were the kind that produced cottony egg sacs, like citrus mealybug, so we naturally recommended Cryptolaemus montrouzieri.
Being visible beetles, though, the client was worried that cafeteria patrons would see them and think bad things about the institute. Fair enough, but since spraying was out, the only option we could think of was to use lacewing larvae. We issued a warning, though: Lacewing larvae, if they adapt, will undergo metamorphosis, becoming pupae, then emerging as adults later. Fairly large, flight-capable adults that might be seen flying around at night. Our contact noted this, but opted to try them anyway. His rationale: There are only a limited number of nighttime patrons so he felt it was less chancy than using Crypts which might be seen during the day when the place was crowded.
The Victims
It was late and the interns were starved as they sat at one of the booths with loaded trays. They dug in, enjoying an extremely early morning breakfast (it was around 3:00 am). The warmth of the food filled their bellies and contentment set in. It didn’t last long, though. One of the interns caught a glimpse of some flying creature. A bug! A hideous, awful bug. The maintenance staff was notified and the problem reported. The maintenance staff then relayed the complaint onto the person in charge of all things botanical within the institute — our contact.
Once notified of the situation, our contact, suspecting the “awful bugs” were lacewing adults, decided it was time to pull a night shift and witness this for himself. Sure enough, the first night showed him all he needed to know: The lacewing larvae, which were up to that point addressing the mealybug issue, had indeed pupated and emerged as adults and could now been seen fluttering around the cafeteria aimlessly, like moths attracted to a porch light.
Adult lacewings are actually beautiful creatures, and completely harmless (they’re not even predatory as adults), but having them fly around the cafeteria at night just wasn’t going to cut it. And if they escaped the cafeteria, they’d be even more unwelcome elsewhere. Something needed to be done.
The Happy Ending
It took a few nights, but the plant and bug guy and his staff were able to find and remove most of the lacewing adults ending their erratic nighttime sorties. Unfortunately, this didn’t solve the underlying problem: the mealies. We got another call. The first thing we heard was how our warning should have been heeded. But we didn’t really know this was going to happen, and neither did they, we just knew it was a possibility.
Despite Crypts being flight-capable, too, we revisited our initial recommendation. They are much smaller, we noted, and less flighty (flying only to get from point A to point B instead of fluttering around aimlessly), and we felt it was a chance worth taking. The plant manager this time agreed to try them, even though he was rightfully concerned. We were, too, though, as we didn’t want our client to have two negative experiences.
As it turned out, the Crypts were released, they controlled the remaining mealybugs, and not once were they even noticed by the staff and patrons. It all worked out for the best.
