Ground beetles in large quantities

Maybe the question is not a topic for Malek,but it's still interesting to know: in 2007, in the spring, in the morning, while I was going to school on the way, I met a huge number of forest ground beetles Carabus nemoralis and some Reptiles (!) constantly crushed them,and in this(2008)year for the whole spring(and already the last month) met only one (and then crushed.... what is it connected with??? did you really pass on everyone last year??? ((

If there were a lot of them only in 2007, then it was probably just a temporary outbreak of numbers. Here is an example: At my dacha (Kupavna Square, Balashikha district) Papilio machaon is not a frequent butterfly, but in 2004 only in one field in a birch grove about 4 individuals could be found in the interval of half an hour.

This post was edited by Nozer - 05/02/2008 10: 20

But in Losino-Ostrovsky Park in Moscow, these ground beetles are also plentiful on the paths this year as in the past, only the exit began a little later.

In our country, nemoralis are also numerous as always, and their presence or absence on the paths depends on the night temperature - if the night is cold, then the beetles are inactive. Well, if you still want to meet them-dig in a few cups, put the bait there and you will have more nemoralis than you need....

According to my observations, hortensis is more common than nemoralis

According to my observations, hortensis is more common than nemoralis

Well, it depends where. In our forests, nemoralis is generally small in number, practically absent (only in some places). And in populated areas, "zaantropogenennyh" zones hortensis day with fire can not be found, nemoralis completely all karabusov "scores". In the forests of the Yaroslavl region, hortensis, along with glabratus, is probably the most numerous species (although in some places, especially in humid areas, granulatus is not inferior).
What is absolutely certain is that over the past 10-15 years, Carabus cancellatus has become ubiquitous in the Yaroslavl region. We have repeatedly discussed this topic with Elizar and Anthrenus, but, stating the fact of a sharp decline in the number of this carabus, we have not been able to come to an unambiguous conclusion about its causes

This post was edited by Dmitrich - 05/04/2008 17: 53

In our country, nemoralis are also numerous as always, and their presence or absence on the paths depends on the night temperature - if the night is cold, then the beetles are inactive. Well, if you still want to meet them-dig in a few cups, put bait there and you will have more nemoralis than you need....

and what to put in the form of bait?

and what to put in the form of bait?

Here, probably, how many entomologists, so many opinions about the preference of baits. But, in my opinion, the simplest and at the same time quite effective method is this (I borrowed it from Anthrenus,a): a plastic disposable "beer" glass is dug "along the edges" into the ground, a penicillin (or similar in capacity) bubble with cotton wool, abundantly moistened with apple or wine vinegar is placed in it. One "but": you should check such traps as often as possible, otherwise larger (or active)predators can destroy the rest of the catch. Because of this disadvantage, many people prefer as bait all kinds of beer-based mixtures with the addition of salt for preserving and fixing objects (while pouring this mixture directly into the glass). This method doesn't seem ideal to me because if you don't make frequent visits to traps, the material may spoil. Although, it's a matter of taste (habit).

tomorrow I will put such a trap in the pre-forest and see how it works))

Maybe the question is not a topic for Malek,but it's still interesting to know: in 2007, in the spring, in the morning, while I was going to school on the way, I met a huge number of forest ground beetles Carabus nemoralis and some Reptiles (!) constantly crushed them,and in this(2008)year for the whole spring(and already the last month) met only one (and then crushed.... what is it connected with??? did you really pass on everyone last year??? ((

Or maybe the population dynamics? In some years, some species may show outbreaks of abundance. As far as I understand, Carabus nemoralis are predators and if there were a lot of them, then they could feed themselves. Probably this year the situation has not changed a little, so the number of them has decreased. But they couldn't be changed. All do not pass Them and pressed them out of excess.

tomorrow I will put such a trap in the pre-forest and see how it works))

A small clarification: the success of the catch will depend on the number of traps placed on a particular site. One trap is clearly not enough. It is better to pour vinegar into the bottle to the top (cotton wool in it has the function of preserving the smell and preventing evaporation-drying).

In my opinion, the number of Nemoralis in anthropogenic conditions is consistently high and is not subject to any significant fluctuations. And the fact that they are being crushed is a consequence of twilight activity and frequent crawling out on the asphalt that has warmed up during the day. They are not crushed on purpose, usually people do not even notice in the dark that something was crawling under their feet...

In my opinion, the number of Nemoralis in anthropogenic conditions is consistently high and is not subject to any significant fluctuations. And the fact that they are being crushed is a consequence of twilight activity and frequent crawling out on the asphalt that has warmed up during the day. They are not crushed on purpose, usually people do not even notice in the dark that something was crawling under their feet...

At the expense of "for the day" I don't know, they were already crushed in the morning when I went to school, well, the "leftovers" were still crawling)) and in the evenings I never met them