Estoloides Breuning, 1940

Heffern, Daniel & Santos-Silva, Antonio, 2017, Notes and descriptions on North American Desmiphorini (Coleoptera, Cerambycidae, Lamiinae), Zootaxa 4247 (4), pp. 469-479 : 470-471

On Estoloides Breuning, 1940 , Tigrinestola Breuning, 1949 , and Pseudestoloides Breuning & Heyrovsky, 1961

Linsley (1942) questioned the inclusion of Lypsimena tigrina Skinner, 1905 in Estola Fairmaire and Germain, 1859 by Schaeffer (1906): “This species belongs in a different group from the two preceding [ Estoloides sordida LeConte, 1873 , and Estoloides sparsa Linsley, 1942 ], characterized by the more elongate, less robust form, narrow lower lobe of the eyes, and the less sloping mesosternum. Its assignment to Estola , however, needs further confirmation.

Breuning (1940) described Estoloides as follows (translation): Elongate, antennae longer than body, with ventral side fringed, the first segment short, thick, strongly clavate, the antennomere IV distinctly longer than V. Antennal tubercles wide apart. Eyes coarsely facetted, strongly emarginate, the lower lobes transverse. Frons transverse. Pronotum transverse, arched, finely and transversely sulcate near base and apex, with long lateral spine at midpoint of sides. Elytra long, slightly wider than pronotum, slightly arched, apex rounded. Head not retractable. Prosternal process lower than the coxae, evenly rounded. Mesosternal process gradually inclined toward anterior edge. Mesocoxal cavities open [closed according to Breuning 1974], the legs moderately long, femora claviform, mesotibiae dorsally sulcate, claws closed. Throughout with sparse setae, including the scape.

Later, Breuning (1949) described Tigrinestola (translation): Estola tigrina Skinner (1905, Ent. News, XVI, p. 291) is to be excluded from the genus Estola Fairmaire and Germain. This species is close to those of the genus Estoloides Breuning , but differs not only by the general appearance but also by the absence of erect setae on the elytra, as well as the lateral tubercle of the pronotum which is obtuse. These characters are enough to create a new genus for this species. I propose the name of Tigrinestola .

Finally, Breuning and Heyrovsky (1961) described Pseudestoloides (translation): “Elongated. Antennae slender, slightly longer than body, fringed beneath with short setae, the scape slightly long and very strong, the antennomere III slightly longer than IV, much longer than scape, the antennomere IV much longer than remaining antennomeres. Antennal tubercles separated and slightly noticeable. Eyes coarsely faceted and strongly notched. Gena very short. Frons transverse. Pronotum transverse, tri-lobed at base and with very long and slender lateral spine, slightly curved. Scutellum pentagonal. Elytra long, slightly wider than pronotum, widely truncate at apex and with rows of punctures. Head not retractile. Prosternal process slightly wide, a little lower than coxae and rounded. Mesosternal process with rounded tubercle. Metasternum with normal length. Mesocoxal cavities open. Legs of medium length, the femora slightly claviform, the mesotibiae with slightly dorsal sulcus, the claws divaricated. Nearly all these characters are not useful to separate Pseudestoloides from some other genera of Desmiphorini , mainly because some of the characters are specific or tribal features.

Chemsak & Linsley (1966) reported: “The present paper is intended to demonstrate that the genus Tigrinestola , as defined by Breuning, has geographical and taxonomic validity, even though it is not possible with the material presently available to characterize more than two species which might be assigned to it. Nevertheless, Tigrinestola was not redescribed in their work.

Breuning (1974) separated Tigrinestola from Estoloides in his key to genera of American Rhodopinini (translation):

39. Pronotum with a lateral tubercle obtuse [conducting to Tigrinestola ]

- Pronotum with a lateral spine [conducting to Estoloides and Pseudestoloides ].

Linsley & Chemsak (1984) presented a description of Tigrinestola , and pointed out: “The gray and black appressed pubescence, broadly tuberculate sides of the pronotum and relatively short antennae will distinguish this genus. In the same work, when writing on Estoloides , they recorded: “This genus is readily separated from Tigrinestola by the longer antennae, acute lateral tubercles of the pronotum and concolorous pubescence.

The descriptions and statements listed above encompass problems and mistakes. The description of Tigrinestola howdeni Chemsak & Linsley, 1966 , simply made the original description of the genus, based only on the general appearance, absence of erect setae on elytra, and shape of lateral tubercle of the prothorax completely inappropriate. Tigrinestola howdeni , as pointed out in the original description, has “very few longer recurved hairs present at base and apex. Actually, we examined specimens in which the erect setae are sparse, but not “very few and not restricted to the base. Furthermore, the lectotype of Lypsimena tigrina also has a few erect setae on the basal area of the elytra. Thus, we believe that Chemsak & Linsley (1966) could not affirm that Tigrinestola “as defined by Breuning had taxonomic validity. Our conclusion is supported by the following: the main features pointed out by Breuning (1949) as distinctive of Tigrinestola actually are not useful to separate Tigrinestola from Estoloides , and were invalidated by the description of T. howdeni , the presence of erect setae on the elytra and, also: “Pronotum lateral tubercles broadly acute [male]; “Pronotum with lateral tubercle more acute [female]. Also, Breuning (1954) described Estoloides (Spinestoloides) in which the elytra do not have erect setae.

In the same way, the key from Breuning (1974) is not useful, because although usually the lateral tubercle of the prothorax is somewhat obtuse in T. tigrina and T. howdeni , it can also be more acute apically. Furthermore, there are species placed in Estoloides with a very similar lateral tubercle as, for example, E. longicornis Breuning, 1940 , and E. paralboscutellaris Breuning, 1971 . Thus, this character is absolutely useless to separate Tigrinestola from Estoloides . It is curious that Breuning (1974) invalidated his key to genera when he provided the key to species of Tigrinestola (translated):

1. Third article of the antennae slightly longer than scape, pronotum with obtuse lateral tubercle............. .. tigrina Skinn.

- Third article of the antennae as long as scape, pronotum with lateral tubercle rather acute......... howdeni Chems. & Linsl.

Also, the comment by Linsley and Chemsak (1984) on the different lengths of the antennae between Tigrinestola and Estoloides could, eventually, be true only when males are considered. Actually, the antennae in females of some species of Estoloides are not very different from females of Tigrinestola .

Breuning (1974) separated Pseudestoloides from Tigrinestola and Estoloides in the key (translated):

30. Mesotibiae notched [conducting to Tigrinestola and Estoloides ]

- Mesotibiae with a slightly dorsal sulcus. [conducting to Pseudestoloides ].

This feature is quite questionable, since there is a large gradient between these two kinds of sulci on mesotibiae in Desmiphorini . This makes it almost impossible to be confident about where to include some species. Also according to Breuning (1974), Estoloides (except E. ( Spinestoloides )) has erect setae on elytra, while they are absent in Pseudestoloides . However, as seen before, this character seems quite questionable to us, since it is variable in the species of Tigrinestola . This suggests that this feature is more specific than generic.

Actually, a better difference between Pseudestoloides and Estoloides and Tigrinestola is the presence of a small tubercle on the mesosternal process. This tubercle is present in Pseudestoloides and absent from the other two.

Tigrinestola differs from Estoloides by the antennae in the male surpassing the elytral apex, at most, by the last three antennomeres, and the distal third of the abdominal ventrite in the female without a central depression. In Estoloides , the antennae in the male surpasses the elytral apex by more than three antennomeres and the abdominal ventrite V in the female, which has a distinct depression in the center of the distal third. Additionally, the three known species of Tigrinestola have three areas with the integument distinctly exposed, contrasting with the pubescence around them.