Apicrenus fossilis, Maldonado Capriles, Santiago-Blay & Poinar, 1993

PLACEMENT OF APICRENUS FOSSILIS View in CoL

Apicrenus fossilis is nested within the Apiomerini in all analyses. Morphology alone places the Dominican amber fossil amongst the Manicocoris grade, as sister to a clade that comprises Calliclopius + Apiomerus ( Fig. 1 View Figure 1 ). This clade ( Apicrenus + ( Calliclopius + Apiomerus )) is weakly supported (synapomorphies: character 6, state 1, without prepedicellite; character 19, state 2, protibial setae long). Several characters support the placement of Apicrenus in the more inclusive Manicocoris + Apiomerus clade, although all are inferred rather than observed for the fossil taxon (i.e. coded as missing for Apicrenus ): character 39, state 0 (irregular arrangement of female metatibial comb); character 42, state 1 (tergite 8 laterally produced); character 45, state 0 (syntergite 9/10 nearly horizontal); character 52, state 0 (gonocoxa 8 nearly parallel); character 54, state 1 (gonapophyses 8 mostly obscured); character 56, state 1 (gonoplac not fused); and character 111, state 1 (female abdomen with setal patches).

In the combined IW analysis, Apicrenus is recovered as part of the Manicocoris clade, where it is placed as the sister taxon to Amauroclopius and related taxa ( Amauroclopius + ( Ponerobia + ( Beharus + Manicocoris ))). This sister-group relationship is supported by the small size of the ocelli (character 2, state 0) and the triangular apex of the protibia (character 23, state 1). Both characters were observed in and coded for the fossil specimens. The overall Manicocoris clade is supported by characters 45, state 0 (horizontal female syntergite 9/10) and 46, state 1 (syntergite lateral margin curved), neither of which could be observed in the fossil species.

RESIN COLLECTING, RESIN STORING, AND EGG COATING: EVIDENCE FROM THE FIELD, LITERATURE, AND ANCESTRAL STATE RECONSTRUCTION

Table 2 summarizes the published and original observations on resin collecting, storage, and egg coating in Harpactorinae , and associates them with structures that we believe to be functionally tied to these behaviours. Direct observations from the field and lab are also shown in Fig. 2 View Figure 2 . They illustrate oviposition behaviour and egg batches in species of Apiomerus and Heniartes , in addition to prey capture behaviours.

Figure 5 View Figure 5 depicts ancestral state reconstructions for five characters that are most likely to be involved in female resin-storing and egg-coating behaviours, i.e. our morphological proxies for these behaviours, based on prior studies ( Forero et al., 2011): the setation on the abdominal sternites in females and presence of ventral abdominal glands (resin storage; characters 109 – 111), and the presence and degree of sexual dimorphism of the metatibial combs (egg coating; characters 34 and 35). A covering of long and dense setae on the abdomen in the female (character 111), which is also strongly sexually dimorphic (character 110), evolved only once within Apiomerini , at the base of the Apiomerus + Manicocoris clade, and was lost once (long setae; in Ponerobia ) or twice (sexual dimorphism; in Micrauchenus and Amauroclopius ) within the group ( Fig. 5 View Figure 5 ). Long, sexually dimorphic setation in some members of the Diaspidiini is treated as a separate origin within that group. Character transitions for the absence or presence of the ventral abdominal glands are more complicated: our reconstruction indicates that these glands are of independent origins in Heniartes , the Apiomerus clade, and Beharus + Manicocoris within the Manicocoris clade, and are thus not homologous across Apiomerini . A metatibial comb was present at the base of the Apiomerini , but a strongly sexually dimorphic comb that is much better developed in the female than in the male only evolved at the base of the Apiomerus clade.