ScienceShot: Invasive Ladybug Carries Fatal Parasite

The innocuous-looking harlequin ladybird (Harmonia axyridis, shown left) wields a biological weapon of mass destruction. Europe and North America imported the insects in the early 20th century to control pesky aphids. But the harlequin, native to Asia, began to flourish, crowding out the native seven-spotted ladybug (Coccinella septempunctata, shown inset). Scientists previously thought that the harlequin prospered because of an unusually strong antimicrobial immune system, which would protect it from disease in a foreign environment. But the beetle's more potent secret is a fungal parasite, in the insect-afflicting Nosema genus, which lives in the beetle's blood. The parasite doesn't affect the harlequin but fatally overwhelms seven-spotted lady beetles within 2 weeks of infection, researchers report online today in Science. Ladybugs commonly eat the eggs of competing species, so when seven-spotted beetles feast on the harlequin's parasite-laden eggs, the parasite strikes back. Researchers say that foreign invaders fare better when they bring along diseases that they're already tolerant of, while other, closely related species (such as the seven-spotted ladybug) might not enjoy such conquistador-like success.

I used to buy cartons of them in, FedEx Overnight, from Texas, for the greenhouses and never had a smell or bite.

Then, I switched to praying mantids, which became like pets to me. We’d cultivate their breeding in our nursery stock growing fields, harvest the chrysalis (cocoons), and let ‘em hatch out in the GHs, every spring.

From your link:

"In addition to its household pest status[citation needed], it has been reported to be a minor agricultural pest contaminating crops of tender fruits and grapes[7] in Iowa, Ohio, New York State, and Ontario.[8] The contamination of grapes by this beetle has been found to alter the taste of wine.[9]"

Not good.

Save the grapes! harlequin bugs must go!

One thing I found about ladybugs: if they’re hatched in a greenhouse, they will lay eggs there, and keep reproducing for years, reducing the need for flying-in millions more each season.

If they’re imported from somewhere else, they fly away after the food source is exhausted, and because they are carnivorous, will kill and eat each other in the process. They won’t stay and make the house they’re imported into, a new home by laying egg masses.

When homes become infested, it’s because a female has laid a yellow egg mass, and the hatchlings will return and lay their eggs, and the results are overwhelming. Fumigators and specialists need to be called-in, and sometimes the areas where egg masses were laid, need to be physically replaced; attics, eaves, closets, garages etc.

I’ve see that happen numerous times over my 22yrs owning and running a Family Farm Business, to both friends and customers. I usually remove all the insects to my GHs, and they get the repairs done by carpenters, masons etc.

Praying mantids are the same way; carnivorous and will eat each other when the food source runs out and then the remaining will fly away to lay egg cocoons.

One large female became my “girlfriend” for a season, and she used to stay up in my hat’s crown all day, in my office, the fields and in the Jeep on trips to town. I’d feed her raw hanburger, and then take her back into GH-17 every night, where her mate was.

This pic shows them after mating - she’s quite preggers - and she laid the egg mas cocoon on a plant in the GH, ate the male’s head, and she died when the cold weather arrived. They only live one season. She was gentle and affectionate.

http://i1308.photobucket.com/albums/s607/Family_Farm/js_face_zpsea4bd3ae.jpg

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