Pontania with Type VI galls [Smith does not name or describe a species and is ambiguous about whether he considers these host varieties or distinct species on each host.]

[A cross sectional drawing appears in Figure 4, on page 5 of the pdf]

Type VI is the most common Pontania gall-form in California. It is large (10 mm), thick-walled, and protrudes through both upper and lower leaf surfaces. The galls may be round or oval, and the surface is smooth (or pubescent, if the host is so) except for characteristic warty lenticels. Adjacent cecidia frequently anastamose. This category comes close also to the P. viminalis group. On S. sp. near lemmonii in extreme northern California, Type VI galls are pruinose (host plant effect), but nearly all others of Type VI are glossy or lightly pubescent. The most common Pontania in California makes galls that belong to this group, and has been known traditionally as P. pacifica Marlatt. The actual identity of this polymorphic species is unclear, and it is probably synonymous with P. californica Marlatt and others described by him in his 1896 paper. The species attacks S. lasiolepis, especially variety bigelovii Torrey, and the center of distribution is from Monterey County north through Marin County along the California coast. There is another species of Pontania on transmontane S. lasiolepis. Other Pontania making Type VI galls include the very common species on S. lemmonii and Salix sp. near lemmonii, and a rare one on S. scouleriana. Both are common throughout the Sierra Nevada and in the southern Cascade Range.

Pontania pacifica

P pacifica is limited to S. lasiolepis as its food plant.

The galls incited by P. pacifica are quite variable in size, shape, color, and number per leaf. They are found at either or both sides of the midrib in the leaves of Salix lasiolepis. When fully developed they are spherical, oval, or bean-shaped (Fig. 1), as much developed on the upper as on the lower surfaces of the leaf, although specimens much more developed on the lower surface are commonly found, particularly on leaves of fast-growing suckers, some of which have the upper surface only slightly raised above the lamina. Galls with the upper surface more developed than the lower have never been found. The cuticle is smooth, shiny. The color is red, pink, or reddish brown on the upper surface, and green or greenish yellow on the lower; not uncommon are those that are red on both sides, or entirely green. Apparently the development of the red pigment is related to the amount of light received by the gall; the green ones are frequently found on leaves that are in the shadow. The average size is 8.4 mm in the longest dimension (average from 50 galls), ranging from 7 to 11 mm. Most of the galls occur singly or in pairs, one on each side of the midrib, but any number up to 14 galls per leaf has been observed. The higher numbers occur more frequently in late summer (Fig. 2).

Pontania pacifica new species

[Only an adult female description is given]

Range: southern CA