Ragweed leaf eater does not eat ragweed

Community and Forum → Insects biology and faunistics → Ragweed leaf eater does not eat ragweed

ИНО, 13.07.2016 19:36

Here is a paradox: Zygogramma suturalis, of which there are a lot in Donetsk this year, is eaten by everyone except Ambrosia artemisiifolia. In the spring, I met on various autochthonous cruciferous plants, the last time-in general on mullein. At the same time, ragweed runs rampant very close by - not a single gnawed leaf. In general, I have never met a single phytophage on this plant, and when I began to identify this leaf beetle, I was very surprised that it was ambrosia.

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19.07.2016 1:03, Guest

The article describes not the weather dynamics of the beetle, but the nature of its spread from the center of mass reproduction/release in nature. I.e., the comparison is literally with the spread of a physical wave (water, fire ...). And since there was money for the project - the horse was not lying around - knowledgeable mathematicians worked with matmodels and there should not be any mess.

It's just that things will be a little different at different densities. And other densities will be when the invasion settles. As the beetle itself (oligophagus) may well change its preferences over time (due to the changed population structure). His colleague in fate and brother in taxonomy (both genera from Doryphorina) - Leptinotarsa seems to be not such a pest in France, where it was introduced in the 20s of the last century.

In short, on the project, you can paraphrase the verse quoted on the forum by A. S. Danilevsky:
But [Koleo]opters,
Those that are small in size,
Warm our faith
In the biometric scam. )))))

19.07.2016 1:23, ИНО

Oh, there it is. I'm a long way from libraries these days, and I can't read the article. The name is strange, what you have just described has nothing to do with waves as a physical phenomenon. A wave is not a movement of matter (bugs) at all. In the case of the beetle, if I understood the description correctly, it looks more like the genesis mechanism of "witch circles". It is vaguely similar to the wave, but this is purely an external similarity. Well, it's not that interesting compared to the paradox I noticed. And it consists in the fact that this beetle apparently stopped eating ragweed, if not at all, then to a significant extent. At the same time, the transition to other plants cannot be explained by competition from fellow humans: we still have a lot of ragweed, there would be enough for everyone. But for some reason they don't eat it. It's a pity: I have a terrible allergy to her pollen.

21.07.2016 0:41, ИНО

It's done! Finally managed to catch this bug eating ragweed! And more than one:

Obviously, ragweed attracts them only after reaching a certain stage of development, namely the beginning of budding. It would be better, of course, if they destroyed it at the stage of germination at the root. Now the plants are already so impressive that these few beetles are like pellets to an elephant. The hope is that there will be more larvae and their appetites are appropriate.

At the same time, there is also unpleasant news: I discovered the first cultivated plant chosen by this leaf beetle - jerusalem artichoke:

picture: _____639.jpg

It is not clear, however, whether they eat it, or simply chose it as a substrate for mating. But someone is definitely eating it - there are a lot of nibbles on the leaves. And jerusalem artichoke is almost a sunflower. And sunflower is the most important agricultural crop in Donbass. Then think for yourself...

21.08.2016 4:30, ИНО

Finally, ragweed has seen any significant consequences of the leaf beetle's activity.

But this is only in one place, where a stunted low ragweed initially grew on poor soil. By the way, I heard that in America it only happens like this. But on the fat chernozem, which occupies the vast majority of our land area, ragweed grows huge, waist-deep, and leaf-eaters can't do anything against it, no matter how hard they try. But the most interesting thing is that there are much fewer leaf beetles on these large plants. However, eggs have been laid on them and the first larvae have already hatched, which is now all hope.

Fears about eating tapinambur were confirmed: they eat and shit on the leaves.

I should probably write a note somewhere, even if beetles aren't my type to suck. I also recently discovered that this beetle eats yarrow.

This post was edited by ENO-08/21/2016 04: 32