I have done some feeding assays before looking at palatability in marine snails on native/non-native algae and a method that worked for me was to mash up different algal spp, put them on a window screen (with a natural grid), and let the snails eat away. It made it easy to quantify consumption and I was able to make checkerboard-like designs to investigate what was preferred when thinking in terms of diversity and abundance. Another, maybe easier way would be to simply photograph the leaf and measure area (Image J) pre and post consumption. In my opinion these types of trials should not be too time consuming though consumers tend to be finicky when you least want them to be...Hope this helps.

Thanks Dean, great response .

I really like your leaf/image J suggestion .

Cheers,

Meg

I have ran palatability tests in white clover to test for effects of induced defense by using caterpillars in a choice tests. I don't know among how many groups you want to compare, if it is limited this could be a good method.

For methodology see:

http://onlinelibrary.wiley.com/doi/10.1111/j.1438-8677.2009.00234.x/full

Hi. Have compared palatability of native and invasive plants using garden slugs. Leaf disks (i.e., standard size hole punch) put into petri dishes for ca 2 days worked well. Used two slugs, voided for a day ahead of time. Can check change in weight before and after feeding trial as a measure of palatability.

Hi Megan, In 2004 John Morgan (LaTrobe) and I had an honours student (Rhiannon Apted) looking at slug/snail herbivory in grasslands near Melbourne. She ran field and cafeteria experiments looking at preferential herbivory of a number of forb species. It was an excellent bit of research and I reckon a look at the methodology she adopted might be useful (a similar approach to that suggested by Duane) . Alas, as with many honours theses it has never been published. However, John Morgan should be able to provide you with a copy of her thesis. best of luck, josh

Dear Megan,

here is the protocol of an experiment I run a couple of years ago to test if different water treatments on grass affect palatability. Hope it helps!

Palatability test:

Material:

- petridishes

- leaf disc cutter

- Generalist herbivores (snail, caterpillar (E,g, spodoptera littoralis/exigua)

- fine balance

Method:

- Number petri dishes

- Determine herbivore fresh weight and put in petri dishes

- sample whole leaves (if you have enough leaves), put in moistened plastic bags and work fast to avoid excess transpiration

- take to balance table, cut 2 equally sized pieces of leaves and determine fresh weight of both immediately (one is the control leave, one the leaf herbivores feed on (test leave) (transpiration out of an leaf piece with cut ends is really fast, so try to work fast also)

- control leaf is dried and fresh weight/ dry weight ratio is determined

- test leave is given to herbivores, let them eat for at least 12 hours

- dry remaining test leaf after feeding

- use determined FW/DW ratio to determine consumed dry weight

- palatability= consumed dry weight/ herbivore FW prior to feeding

- or: just use consumed dry weight as response variable, and perform ANCOVA with herbivore fresh weight as a covariable (this is the preferable method perhaps, see Horton and Redak, Entom Exp Appl 69, 263-275, 1993)

- additionally you can weigh herbivores after feeding again, and then determine the relative growth rate RGR: gained weight/ [mean biomass of herbivore]*time interval

or see: Wardle et al. 1998, Can comparative approaches based on plant ecophysiological traits predict the nature of biotic

interactions and individual plant species effects in

ecosystems, Journal of Ecology 86, 405-420.

Thank you all,

Much food for thought .

Why no to use Microtechnique od Malechec it is used with esophageal phistulated herbivores, and is based on pland cell characteristics like trichomes, cellulose, etc