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Adalia bipunctata f. typica This once abundant species is quickly becoming scarce and possibly going extinct, due to the arrival of Harmonia axyridis, both as a competitor in the same habitats, but also as a vector of disease. Adalia,Adalia bipunctata,Adalia bipunctata f. typica,Coccinellidae,Coccinellinae,Coleoptera,Geotagged,Ladybird,Netherlands,Two-spot Ladybird,Two-spotted lady beetle Click/tap to enlarge

Adalia bipunctata f. typica

This once abundant species is quickly becoming scarce and possibly going extinct, due to the arrival of Harmonia axyridis, both as a competitor in the same habitats, but also as a vector of disease.

    comments (5)

  1. I just read that, even in the presence of aphids, H. axyridis prefers to predate upon A. bipunctata eggs and larvae! This makes me wonder how crops will be affected since ladybugs are supposed to eat aphids, which cause crop damage. Will the aphid populations and thus crop damage increase in the absence of Adalia bipunctata, and even more so if H. axydris prefers ladybugs over aphids? Posted 2 months ago
    1. From a point of view of crop management Har.axy. will simply replace Ada.bip. and in the end it will probably proof to be a more potent predator for aphid detail. Preferring Adalia eggs/larvae over aphids (if that is true) would make sense for any species as it simply takes out the competition. Also, this food is almost certainly more nutritious.
      From my own experience I would be hesitative to jump to conclusions concerning this feeding behaviour. Imho Har.axy. - especially the larvae - will pretty much bite (and if possible devour) anything that it runs into. It will bite your finger if it can find a spot soft enough, it will cannibalize its own brothers and sisters, especially when these are "ahead" in their development and have already fixed themselves to the substrate to pupate (and cannot run), and of course eggs all sorts are "sitting ducks" - they don't run and they don't bite back. I've seen moms Har.axy. eat their _own_ eggs(!) when food becomes scarce. That makes perfect sense of course. If there is no more food for her, there will be no food for the larvae once they hatch, so it is way more productive to eat the eggs, fly somewhere else and use the nutritional value stored in the eggs to produce new eggs in an environment where there is enough to eat. But I'm also pretty sure mom doesn't think it through like I just did ... eating anything she runs into just works out "intelligently" in this case :o)
      Posted 2 months ago, modified 2 months ago
      1. Good points, Arp! When I first read what you wrote about the moms eating their own eggs, I automatically thought, "how dumb!". But, it makes sense in how you explained it.

        It's sad to see natives pushed out by invasives. Maybe the impact isn't always severe, but it may still be felt in ways we don't know. Maybe it's part of nature, and not always caused by humans, but still...It makes me sad. I root for the natives.
        Posted 2 months ago
        1. Christine, where did you read the stuff about Har.axy. preferring Adalia eggs etc above aphids? I would be interested to read that article ... Posted 2 months ago
          1. Sorry, I should have included the reference yesterday!

            Here it is:
            https://www.researchgate.net/publication/268443532_Predation_behaviour_of_Harmonia_axyridis_on_Adalia_bipunctata


            Citation: Hautier, Louis & Branquart, Etienne & Jansen, J-P & Grégoire, Jean-Claude. (2010). Predation behaviour of Harmonia axyridis on Adalia bipunctata. IOBC/wprs Bulletin - Benefits and Risks of Exotic Biological Control Agents. 58. 45-46.
            Posted 2 months ago, modified 2 months ago

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''Adalia bipunctata'', commonly known as the Two-spot Ladybird, Two-spotted Ladybug or Two-spotted Lady Beetle, is a carnivorous beetle of the family Coccinellidae that is found throughout the holarctic region. It is very common in western and central Europe and North America. It is used as a biological control agent.

Similar species: Beetles
Species identified by Pudding4brains
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By Pudding4brains

Public Domain
Uploaded Jun 25, 2019. Captured in Vreugderijkerweg, 8042 Zwolle, Netherlands.