Eupithecia monticolans (Lepidoptera: Geometridae)
Eupithecia monticolans (Lepidoptera: Geometridae)
| Larva |  | Adults; male (above) and female |  |
The larva is usually green as above but also ranges to solid purple and solid brown.
This species is at least a facultative carnivore. The early instars may feed on pollen (known especially from `ohi`a), but I had trouble rearing it for a long time because flowers didn't seem to be enough to keep it going. Finally I noticed one day that a caterpillar was feeding on psyllid galls on 'ohi'a leaves that I had happened to put in its rearing pot. From then on I had no trouble rearing E. monticolans caterpillars of any instar by giving them a good supply of psyllid-gall-covered `ohi`aleaves, which they turned quickly into swiss cheese. I still have no idea what they eat on the other host plants, none of which seem to have similar galls; I was unable to rear them off several plants from which they were collected.
They appear to be somewhat of a 'missing link' between leaf-feeding geometrids and the obligatory carnivores in the genus (such as E. orichloris and E. rhodopyra on this list). Eupithecia are apparently preadapted for the digestion of high protein, which facilitated evolution to a predatory form. So far the carnivorous Eupithecia are known only from Hawai`i, but that may be due to insufficient knowledge of the genus (which is widespread) in other regions.