Smaller insect species are more susceptible  to residual insectides, than the bigger species, but it also depemds on the insecticide and its mode of action like for example DDT, or neonicotinoids. The last one had a magor role in the CCD the colony colase disorder of the honeybees. Any way the polution doen't differetiant between smaller or bigger animals, but all the biosystem is threatened.

It is not easy to get such data, there should be research.

Please see the following link:

Article Insecticides mode of action in relation to their toxicity to...

Dear Klaus,

Your question is too genuine, the smaller insects due to their low immunity, are too vulnerable towards the toxicity of insecticide such that they easily response towards it. Also, even a small fluctuation in the abiotic factors i.e., temperature, humidity, light intensity, water availability, wind velocity, etc affect their population following to the introduction of stress within them. In contrast to it, the larger insects due to strong immunity, becomes resilient towards the toxicity of insecticide, hence they easily develop tolerance towards it.

Therefore, in nutshell, it can be hypothesize that smaller insect are much more sensitive towards to toxicity of insecticide.

Best of Luck.....!!!!

Dear Aarti, as you say: probably smaller insects are much more sensitive to insecticides! Badluck for insect diversity, particularly for a high number of small parasitic and hyperparasitic insects! This means that the disturbance of biological equilibrium by insecticides is much higher than most studies suggest, because most of them concentrate on pollinators, which are probably within the size class of most target insects.

Dear Klaus,

I do not know specific experiments, but you are right; smaller insects should be more affected by insecticides.  Their higher ratio surface/volume makes them more sensitive to heat, dryness and other stressors which effect depends on the relative surface; this is the case of most insecticides diffusing through the cuticle.

Un abrazo!

Claudio

Dear all,

we did some work with bee species and their lab sensitivity towards one insecticide (dimethoate). In these highly controlled experiment bee species weight and acute contact toxicity show a relationship. I attached the paper and a talk with updated data. However, we only tested 8 species (5 in paper) up until now so the dataset is still quite small.

Furthermore, extrapolating lab results to the field is always tricky. In the agricultural landscape not only the toxicity of pesticides but also the potential for exposure to them and pesticide-unrelated population dynamics are relevant factors. Since Klaus asked if there is data: I would imagine that with the dataset of the Krefeld Entomological Society it should be possible to investigate such a hypothesis. They have long-term monitoring data. All you need now is information on species size and you could have a look if smaller species' abundances are decreasing disproportionately.

All the best

Philipp

https://www.uni-koblenz-landau.de/en/campus-landau/faculty7/environmental-sciences/ecotoxicology-environment/teams-profile/terr-ecotox/philippuhl/setac-brussels-bee-talk

Article Interspecific sensitivity of bees towards dimethoate and imp...