Electrocuting a fruit fly using magnetic induction
Electrocardiac functions are pure chemical potential activity with no magnetic field.This is because the material is mainly an insulator which descibes all dielectrics, with some dielectric constant, effective series resistance, (ESR), dielectric constant time that of and thus requires a certain Energy level to activate without damage. 

The ESR is responsible for all the heat in capacitors as well as skin burns from the ESR between the electrodes and the cardiac function.

So the objective must be to minimize the ESR which takes perhaps 1000 times (guesstimate) the energy on the chest of a human compared directly on the heart muscle in surgery.  Thus attenuation is unavoidable in humans even with large paddles and high k dielectric grease. A similar problem will exist for you on insects and made much harder by the tiny surface area.  

Immersion in the dielectric would help greatly but possibly drown the insect.  The surge is a high amplitude ,very fast decay due to the low ESR of the interfacial ionization and ESR*Ceq. for the equiv capacitance of the discharge unit and target combined in parallel.

The desired solution is to use properly sized storage capacitance and voltage including cables at 50pf/m typ for twisted pair but use a higher voltage that will exceed the breakdown voltage (BDV) of the carapace.

The energy in any capacitance including the 300pF human finger model is E=1/2CV^2 in Joules , Farads and Volts. Thus a finger at 10kV from a nylon carpet with neoprene shoes will arc 10mm from a thin wire with 300pF or so is E=1/2 300e-12* 1e4^2= 15 mJ

You might only need 1kV with 1mJ to exceed BDV, trigger a cardiac function or failure, and not make fried protein.

Microwave pulses are not the same as a capacitance discharge, as the storage capacitance tends to be too high in order to get sufficient high BDV.  Although 1kW microwave oven can generate 10kV it is too much energy.  

I suspect the insect BDV is perhaps 1 to 10 kV/mm (guesstimate) like damp wood (not dry) but not mica or kapton which has a much higher kV/mm. I believe the pH level will determine most likely, the BDV/mm carapace material properties as this promotes partial discharge, an early precursor of of BDV.

So get a friction charge generator and make some small film cap or mica range of small caps xxx pF to charge upto 1kV then test on damp wood of same size as fly body.  If arc works ~1mm then observé response and adjust C or V to fine tune the forces of a toothpick and electrode needle heads to apply to side to see if it tries to turn with the impulse current in 1 us.   Current sense R's may be used in series with 10:1 probe across 1kV rated R with 0.1 ohm but probe ground and tip must be removed and wired directly to probe tip and barrel. Otherwise it will ring badly.

Now that's what I would do. The charge process could be done safely with some tech advisor.


  Otherwise get a non ESD proof Nylon carpet and Neoprene shoes and do it the old fashioned way. hahaha. Don't forget the needle heads and suitable grease.