Andricus partali (sexgen)

Striatoandricus guatemalensis (agamic)

Andricus partali n. sp.

[The phenology, gall morphology, and adult morphology of this species seem to closely match North American members of the genus Dryocosmus; it isn't clear why the species was placed in Andricus]

[A photo of these galls appears on the last page of the pdf]

Gall (Fig. 6a). Globular swelling of the leaf blade projecting on both the upper and lower surface of the leaf, located adjacent to the main vein or a secondary vein. Usually there are only one or two galls on a single leaf, rarely more. The gall is up to 10 mm in diameter, green in color, sometimes with a slightly reddish tinge on the surface. The external wall is coriaceous, quite hard, and with a shiny surface. Mature galls are hollow inside and within the internal air space is a single 2-3 mm diameter, brown sphere containing the larval chamber, which can become detached and capable of rolling around inside the hollow interior of the gall.

Biology. This new species was found inducing galls on Quercus costaricensis Liebm. (Section Lobatae of Quercus, red oaks), which occurs from 2300 m to 3600 m elevation in Costa Rica and western Panama (Morales 2010). The gall appears to belong to the sexual generation. Mature galls were collected in March-April, and adults emerged soon after the galls were collected. Other hymenopterans that emerged from these galls include parasitoids, Quercastichus sp. (Eulophidae) and Torymus sp. (Torymidae). 

Distribution. Only known from high elevations in Costa Rica (Cordillera de Talamanca).

Andricus guatemalensis

[Striatoandricus guatemalensis and Andricus partali occur on different groups of oaks (white and red, respectively) so it is almost certainly that they are not closely related. It is not clear why Pujade-Villar et al compare them.]

Cameron (1883: 71) described Cynips guatemalensis based exclusively on gall samples, however the drawings of the galls in the same study (Cameron 1883: Table 4, Figs 7 & 7a) were morphologically discordant from his description in the text. Furthermore, Synergus dorsalis Cameron was described in the same study (Cameron, 1883: 72); the type material of which (adult) was examined by Richie & Shorthouse (1987: 240) who concluded that it corresponds to an Andricus. Cameron mentions that S. dorsalis was obtained from the gall of Cynips guatemalensis, therefore S. dorsalis, currently Andricus dorsalis (Cameron), would be the inducer of the gall of C. guatemalensis (currently Andricus guatemalensis). The gall of Andricus partali n. sp. may be similar to the description of Andricus guatemalensis (Cameron). Ritchie & Shorthouse (1987: 240) also studied the type material of A. guatemalensis (gall), labelled by Cameron, and the authors compared it with “Andricus? mexicana Bassett”, a velvety leaf gall; then, they confirmed that A. guatemalensis (gall) corresponds to Cameron’s drawing (Fig. 6b), a velvety leaf gall. Thus, the description of A. guatemalensis (gall)is erroneous. According to the ZNC, a drawing cannot be a type (nor a description); a ‘Type’ should be a sample, or a synthetic series of samples (Brothers pers. com.). Thus, the type series of A. guatemalensis (gall) and of Andricus dorsalis (adult) deposited in the British Museum are the true syntypes of both species, and not the description by Cameron. Pujade-Villar et al. (2011) considered Andricus mexicanus Bassett and Cynips guatemalensis Cameron as incertae sedis, since they were described based only on the velvety leaf galls, which are impossible to differentiate from other velvety leaf galls on leaves that are known. Based on the conclusions of Ritchie & Shorthouse (1987) we know the inducer of the gall Andricus dorsalis (Cameron) and after having the opportunity to examine the type of this species we conclude that it belongs to the tecturnarum group (JP-V unpublished data). Therefore, A. guatemnalensis is a species morphologically distinct (both the gall and the adult) from the new species described here, and Andricus partali n.sp. is a valid species distinct from A. guatemalensis (= S. dorsalis). As was mentioned, neither a description nor a drawing are “valid” for anything beyond providing information about which the author considered relevant, and either (or both) could be erroneous in several aspects. In summary, even though the description of the gall by Cameron is similar to that described here and given that the verbal descriptions do not correspond to the drawings, the only way to determine the correct application of names is to examine the type specimens. By this means it can be decided whether the descriptions or the drawings are more precise. For these reasons, Cynips guatemalensis, considered in this study as dubida species, corresponds to a multilocular velvety gall on the leaves (Fig. 6b-c) very distinct from the leaf gall described here (A. parlati, Fig. 6a). 

Andricus partali n. sp. de Costa Rica (Hymenoptera: Cynipidae: Cynipini)