At the time of getting familiar with the genus...

In the summer of 2008 I had the opportunity of visiting Dr. Charles O'Brien's Collection (CWOB), looking for identified Lachnopus specimens in order to include them in my analysis. Part of CWOB's specimens had been compared with types in European collections. In only 10 days of careful observation I learned a lot about the group.

I'm going to illustrate some of my observations with images of morphotypes of L. curvipes (Fabricius, 1787) which I presented at the ESA meeting in 2011. You can access the whole presentation here.

- There is sexual dimorphism: the usual, males are slender and sometimes smaller than females; something quite 'particular', the males have a slightly longer or slender rostrum than the females, which is the opposite of what can be observed in the Curculionidae in general.

- The posterior tibiae are also dimorphic in several species. Usually the male posterior tibiae are hairy in comparison with those of the females.

In this species the dimorphism can be considered extreme, judging by the presence of a very developed tooth in the male tibia, but if you see only the amount of hairs, you get the idea.

Beyond these characteristics which apply to several species, I've found a couple of identification conflicts among CWOB identified specimens:
 - (L. atramentarius vs. L. inconditus), (L. planifrons vs. L. mundus) result very similar, there was at least one specimen of each compared with the type but, for one species it was a male compared and for the other it was a female.
- The group formed for (L. coffeae, L. seini and L. yaucona) is not easy to separate... there are seven species recorded from Puerto Rico: L. coffeae (along with the variety L. coffeae montanus), L. curvipes, L. kofresi (from Mona Island), L. seini, L. trilineatus, L. valgus and L. yaucona. Until now I can only recognize L. kofresi which is quite distinct from all other Lachnopus known to me, L. curvipes, which is the most widespread and variable species and the remaining, except for the montanus variety of L. coffeae, might possibly be variations of the same species.

There are also some specimens from Cayman Islands, Cuba and Jamaica that are probably undescribed.

The most important conclusion of this 'get to know Lachnopus' phase was that the variation within the genus is quite extreme, over all on the head appearance (including the shape of the rostrum, the projection of the eyes and the width of the frons), colorations and scale distribution patterns. In some cases there is also intraspecific variation.

At this time and after my experience with Apodrosus I knew that the phylogenetic analysis was not going to be easy!