syngoniums:

We went to Fredericksburg last Thursday and stopped by the garden in the Marktplatz. We had a very warm November, and everything’s in bloom as if it were late spring. There were a tremendous number of insects too, including many monarchs. Generally the bulk of migrating butterflies will be at the Texas-Mexican border by mid to late October, but this year they’ve been delayed across North America, most likely by atypically warm weather. It remains to be seen how successful these stragglers will be, seeing as they will be undertaking the last leg of their journey in December.

Tropical milkweed (Asclepias curassavica) has been implicated by some in delaying or interfering with migration, in that it prompts butterflies to linger and lay eggs. I personally think it’s a relatively small factor, if it is one at all, compared to the effect of warm autumns. (Of greater concern might be the fact that it is relatively more likely than native milkweeds to host spores of the protozoan parasite Ophryocystis elektroscirrha due to its lack of a dormant phase, but this can be managed if the plants are killed by cold weather or periodically cut to the ground.) Monarch debates aside, the bulk of the other butterflies and nectarivorous insects present do not undertake any significant migration, so abundant flowers are certainly benefiting them, at least!