Friend or Foe?

[Len Rhind]

I was just browsing a book of bugs and the authors seemed to be of the opinion that all butterfly caterpillars were okay, except the cabbage, and that all moths were not good caterpillars. I do not know if this is so, but they were confident enough to go to print with it.
Len

[Paul T]

Knowing what the butterfly caterpillars that attack citrus do, I wouldn't exactly call them "good".  They're good at eating, but I don't think that is what they are meaning.  They can very efficiently strip all the new growth off the tree, all the while disguised as bird droppings..... the caterpillars that is, not the new growth.

[kirsitn]

I was just browsing a book of bugs and the authors seemed to be of the opinion that all butterfly caterpillars were okay, except the cabbage, and that all moths were not good caterpillars. I do not know if this is so, but they were confident enough to go to print with it.

That sounds like an utterly ridiculous book...  Most species of both moths and butterflies have very specific host plants for their caterpillars, and will therefore not attack garden plants unless you happen to grow their native host plant in your garden. (In which case they should - in my opinion - be allowed to eat the plant.) It may be true that there are more omnivorous moths than there are butterflies, but under normal circumstances neither of them should cause any major problems in the garden.

And remember that the hungry caterpillars turn into beautiful winged flowers. 

[Anthony Darby]

Butterfly caterpillars tend to be specific in their feeding preferences, e.g. Fritillaries feed on Viola spp.; the big nymphalids like the Red Admiral (Vanessa atalanta), Peacock (Inachis io), Comma (Polygonia c-album) and Small Tortoiseshell (Aglais urticae) feeding on nettles (Urtica spp.); the Browns (Satyridae) feed exclusively on grasses; the blues feed mainly on vetches, and specific ones at that (Adonis blue - horseshoe vetch; small blue - kidney vetch) etc. The exception is the Holly Blue (Celastrina argiolus) which is just spreading into Scotland due to global warming. It is double brooded, with the adults emerging from overwintering pupae laying their eggs on the female Holly (Ilex spp.) flowers. The larvae then eat the developing berries. The second brood in the summer lay their eggs on ivy blossom. These larvae feed on the developing ivy berries.

Many moths are polyphagus (feed on a wide variety of plants). The Large Elephant Hawk, while not exactly polyphagus, feeds normally on willowherbs (Epilobium spp.), in the garden it has been found commonly on Fuchsia. I use to see 'woolly bears' (the larvae of the Garden Tiger Moth Arctia caja) quite commonly but not now. They feed on docks, dandelions and most other low growing plants. Most of the big brown Noctuid moths are fairly indiscriminate feeders too and are thus pests in the garden.

[Lesley Cox]

My woolly bears always feed on Senecio species, of which there are many weedy ones around here. Unfortunately they also like S. candicans (which I also have as S. magellanica).

[Gerdk]

Last year I found this tiny larvae (Dipterae) - about 2 - 3 mm - which crept out of a collected seedpod of a Turkish viola species.
I add this pic here hoping for identification.
They looked like mini carrots.

Gerd