[For full-size image, click this link...then click the image again after it loads in your browser window.]
This mating pair was found by Alice Abela after we spent a few hours searching. A week earlier she had discovered a population here of what seemed likely to be a new species of Timema
, feeding on the hitherto unknown host plant Hesperocyparis sargenti
(or "Sargent's Cypress"). Shortly thereafter, Alice attended a talk on Timema
and found out from researchers Patrik Nosil and Cristina Sandoval that the population was known to them, and represented a new and as yet undescribed species.
The initial four photos of this series show both members of this mating pair feeding on foliage of Hespercyparis sargenti
In the 1st photo, above, the female can be seen chewing terminal leaf scales (note her black-tipped and toothed mandibles)...with the male patiently waiting on her back for his turn.
In the 2nd photo, after the female starts chomping a bit further down from the branch tip, the male gets a chance to join in (he also has black-tipped and toothed mandibles).
The 3rd and 4th photos show the same feeding sequence repeated 7 minutes later on the same branchlet tip.
I'm curious whether the mandibles (color and/or the number of teeth?) might provide diagnostic characters for separating Timema
species. Alice has two nice photos showing the black tipped mandibles for this same mating pair here
. However, as the 5th image in this series shows, unless one photographs Timema
feeding, it appears the mandibles will usually be hidden from view by the labrum and/or labium (cf. diagrams here for grasshoppers
...though I think the mandibles of Orthoptera are much chunkier than in Timema
, and the maxillae in Timema
lack toothed (lacinia) shown there for Orthoptera).
The 5th photo provides a face-on view of the pair and shows how the mandibles are retracted and hidden from view under the labrum when not feeding.
The remaining photos of this series mostly show diagnostic characters of the terminalia. After studying the taxomomic references [e.g. Vickery(1993) and Vickery & Sandoval(2001), etc.] it seems to me that as far as terminalia go, this entity lies somewhere between T. californicum
and T. petita/landelsensis