ENV - Ladybug population in decline

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Ladybirds becoming harder to spot

By Peter Foster

THE ladybird, friend of gardeners and favourite of children, is in sharp decline, scientists and wildlife enthusiasts have warned.

Studies conducted by a network of amateur natural history societies have shown that numbers of the beetles have dropped sharply in the past four years. Ladybirds, also known as "Bishop Barnabee" or, in Yorkshire, the "cushcow lady", are vital in controlling greenfly and other aphids which feed on garden plants.

Paul Mabbott, an ecologist with the London Natural History Society, said his members had detected a sharp fall in all 29 lady species. Similar reports have been made in Northants and Sheffield. The decline could be traced to a severe frost in the spring of 1998. In Scotland, a study has discovered unusually high levels of a parasitic wasp, Dinocampus Coccinellae, that feeds exclusively on ladybirds.

Gardeners are urged to keep old roses to provide plenty of aphids as food for the ladybirds. Alternatively they can buy ladybirds from shops specialising in organic pest control. A ladybird larva can eat 50 aphids a day, a lace-wing larva up to 300. However, a box of 25 larvae costs £12.

-- Anonymous, April 17, 2001

Answers

Hard to keep ladybugs straight these days. A few years ago there was an invasion by a ladybug-like insect, that came in swarms and came inside. Harmless except that there were so many of them. I wonder if they are displacing our old friends.

-- Anonymous, April 18, 2001

According to the report, it was a spring frost and/or a parasitic wasp. I wonder if this sudden frost here has done harm to them too?

Those Asian ladybugs, from what I remember, weren't displacing the domestic kind--just that they were prone to seek winter shelter indoors and they would gather in huge clusters in the corner of a room! They look very much like the domestic kind, except more spots, I think. I don't believe they've made their way to the UK yet.

I see ladybugs on my roses sometimes but not often. When I do I figure someone in the neighborhood bought larvae.

-- Anonymous, April 18, 2001


The invasion in the US a couple years back was the Mexican Lady Beetle. They've almost displaced the domestic ladybug-- I know that hundreds overwinter in my house every year! (And unfortunately, the cats won't eat them. They love a good housefly, even the occasional spider, but they won't eat ladybugs. Too crunchy, I guess.) Anyway, I'm sweeping them up in hordes this time of year. They come inside around Halloween, and head out again around Easter-- that is-- in the Midwest.

-- Anonymous, April 18, 2001

Oh, dear. I meant to say the Asian Lady Beetle, not Mexican. I guess I've been fretting too much over Mexican Bean Beetles lately! Apologies!

-- Anonymous, April 18, 2001

About ladybug (or Mexican or Asian ladybugs) invasions: Last October one Friday afternoon it seemed like every ladybug in East Tennessee wanted to get into the house. It was like a sci-fi movie. Literally swarms (like gnats on a lake), about a dozen per sq ft on the outside. They managed to crawl thru the patio doors, we madly duct taped the patio doors, only to discover they had found a crack in the basement door. We fought like fanatics for several hours. I'll bet I've swept up several QUARTS of dead ladybugs in the basement. I'm thinking of inventing a ladybug trap of some sort for this fall, a box with a small lightbulb in it. They seem to sense heat differentials better than a sidewinder rattler. So the box would have a narrow slit sos they could get in. So if you-uns have any good ideas on trapping ladybugs, PLEASE let me know!

-- Anonymous, April 18, 2001


I think all the ladybugs are in South Dakota. We starting digging shrubs at work today and I was covered with the little darlings in no time.

-- Anonymous, April 18, 2001

CROSSVILLE CHRONICLE News Asian Lady Bugs Infesting Homes By Roger Thackston
Special to the Chronicle Several Cumberland County homeowners have found the multi-colored Asian lady beetles invading their homes in search of a protected overwintering spot. Homeowners have reported thousands of beetles on the sunny side of homes. If a crack or crevice is found, they will move inside a wall, attic, crawl space and may find their way into the living areas of homes. Asian lady bugs were first introduced into the United States to control aphids and are considered of be a beneficial insect. They are distinguished from regular lady bugs as they are bigger, have black spots that form an ÒMÓ or ÒWÓ behind the head and spots ranging in number from none to 19. These beetles do not sting or bite, do not carry diseases and do not eat wood. However, they can stain wallpaper and upholstery and stink when crushed. There are those individuals with insect allergies being irritated by their presence. Homeowners ask the question, Why are they attracted to my home and not my neighbor's? These beetles seem to be attracted to light-colored walls on the south or southwest side of homes, but this is not always the case. Dark-colored buildings are sometimes invaded. Large windows or other reflective surfaces may also attract the beetles. How can you prevent the Asian beetles from entering your home? Exclude them! Starting in September seal cracks and crevices where they may enter. Gaps of one-eighth inch or less will allow entry. Caulking around window frames and siding, installing door sweeps, adding rubber bottom seals to garage doors and foam weatherstripping under sliding glass doors may prevent entry to a home. Utility openings into a structure, such as outdoor faucets, gas meters, dryer vents, wires, etc. should be sealed. Make sure damaged window screens are repaired and insect screening is installed behind attic and crawl space vents. Areas where the beetles have congregated on the outside of homes can be cleaned with a mild detergent to remove any material which may attract other beetles. Once winter is upon us, problems from lady beetles on the outside of homes and also inside the home will lessen. But when the outside temperatures begin to warm-up in the spring, so will the lady bugs. At this time, the beetles will begin to search for a way to the outside because they are thirsty and hungry. In their search to find their way to the outside, many make a wrong turn and find their way to the interior of a home. Try to locate entry points and seal. Once they find their way inside a home, they will usually congregate near or around a window where they can be vacuumed and released outside in a protected area. Some gardeners collect the beetles, place them in a fruit jar with air holes in the lid, add a piece of cardboard for them to crawl on, and store them in the refrigerator. Once a week, the jar is removed from the refrigerator and little water sprinkled into the jar. As the beetles warm, they will become active and drink the water (let them drink for about 30 minutes). Return the jar to the refrigerator. Do not place the jar in direct sunlight or other warm areas for very long. Come spring when the aphids become plentiful and daytime temperatures remain above 55¡, release these predators outdoors in a protected site. Using insecticides to kill the lady bugs inside the home doesn't make too much sense, because they will still have to be vacuumed. Fogging is also discouraged as the only beetles to be killed will be those contacted by the spray and those in the cracks and crevices are unaffected. Dead insects may also attract carpet beetles. If you have experienced an Asian lady beetle infestation and sealing the outdoor entry sites is impractical, a professional pest control company may be needed. They will apply insecticides to possible entry points. This only works as a preventive treatment and must be done before the beetles enter the structure and it still may not be very effective. The thing to remember is that this beetle is providing a huge service by eating aphids and should not be killed whenever possible. Experts say the beetle population will eventually exceed it's food supply and their numbers will crash or reach a lower level on their own.
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Roger Thackston is the extension leader for Cumberland County with the University of Tennessee's Agricultural Extension Service.

-- Anonymous, April 19, 2001

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