California Psyllid Watch: Island Mallow Psyllid

Island Mallow (Malva (formerly Lavatera) assurgentiflora) is a plant endemic to the California Channel Islands, but also grows along the California coastline from San Diego north to San Francisco. There is another California endemic species, the psyllid Bactericera lavaterae, which I'll call the Island Mallow Psyllid (IMP) which is tied specifically to this plant. The psyllid does not seem to be particularly rare, and it can be sometimes be found in large numbers on its host. However, you'll notice that this species is not represented on iNaturalist, or on BugGuide, or well, pretty much anywhere.

But that's not to say there are no photos of it on iNaturalist. In fact, there are several, all photobombing Island Mallow submissions. Take a look at this observation from Nicole LaRoche in February 2015, for instance. There are actually over half a dozen psyllids in this photo:

Image © Nicole LaRoche(CC BY-NC 4.0)

If you take a look at that image again, you'll notice that the leaves, especially the leaf right above the flower, is covered in blister-like impressions. This is the most conspicuous sign of IMP's presence. On the ventral surface of the leaves, close examination of those depressions would reveal the nymphs. Nicole's image was taken on Anacapa Island, but the psyllid, like its host, is no longer limited to the Channel Islands: it is recorded throughout the host range, from San Diego to San Francisco. Here is another iNat observation, from user jemhikes, from San Diego. You'll notice immediately the blister-like impressions on the leaves, and if you zoom in, you should be able to find two psyllids, one on the leaf and another on the flower.

While winter is not exactly psyllid season, you'll notice that these two observations were taken in January and February, and the psyllid has been commonly taken in December as well. Therefore, now is the best time to start looking for this species. If you know of any locations where Island Mallow is grown, take a look at the leaves for signs of its existence in the form of leaf blisters. If blisters are present, take a look at the ventral surface of the leaves for nymphs, and be on the lookout for adults! Close-up photos and observations of this species would be very useful contributions.

Publicado el diciembre 11, 2016 06:53 MAÑANA por psyllidhipster