Hesperiinae

Cock, Matthew J. W., Congdon, T. Colin E. & Collins, Steve C., 2016, Observations on the biology of Afrotropical Hesperiidae (Lepidoptera). Part 9. Hesperiinae incertae sedis: Zingiberales feeders, genera of unknown biology and an overview of the Hesperiinae incertae sedis, Zootaxa 4066 (3), pp. 201-247: 238-244

publication ID

http://doi.org/10.11646/zootaxa.4066.3.1

publication LSID

lsid:zoobank.org:pub:680D0FB4-F3BC-4562-B214-631067287218

DOI

http://doi.org/10.5281/zenodo.5614548

persistent identifier

http://treatment.plazi.org/id/0386D843-FF85-B118-CEEC-96452739F98C

treatment provided by

Plazi

scientific name

Hesperiinae
status

 

Discussion, Hesperiinae   incertae sedis

This paper completes our treatment of Hesperiinae   incertae sedis. We have treated this assembly of genera in five parts: dicotyledon feeders ( Cock & Congdon 2013), palm feeders ( Cock et al. 2013), grass and bamboo feeders (Cock & Congdon 2014), Dracaena   feeders (Cock et al. 2015) and Zingiberales   feeders (this paper). The 37 genera treated and their food plant families are summarised in Table 2 View TABLE 2 , leaving only 11 genera for which nothing is known of the food plants or life history.

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1 Families in bold were documented in our work, others are from the literature.

2 + from literature or museum specimens; ++ our observations; +++ photograph.

3 As noted above, T.B. Larsen (pers. comm. 2015) intended to create a new genus for this species. Evans (1937) placed it in Xanthodisca   in Ceratrichia   group, but its affinities are not clear.

Ova. A priori   , it seems likely that differences between ova are likely to be more conservative, than any observed amongst caterpillars or pupae, which are likely to show adaptations to avoid predation and parasitism and related to their food plants and leaf shelters (e.g. Greeney et al. 2012). However, this is not necessarily true as mortality of ova has been shown to be important in pest Lepidoptera   such as the polyphagous noctuid Helicoverpa armigera (Hübner)   , where egg predators play an important role in Kenya (Van den Berg et al. 1999). MJWC noted that significant numbers of Artitropa erinnyis (Trimen)   ova disappeared from a Dracaena steudneri   plant in his garden in Nairobi (Cock et al. 2015). Hence, adaptations to maximise adhesion of ova to different types of plant surfaces, or minimise the ability of predators such as ants to remove ova are certainly possible. We have images for only 14 genera ( Figure 41 View FIGURE 41 ), but they do seem to indicate some groups within the incertae sedis. The genera Parosmodes   , Semalea   and Platylesches   are united by have having wall-like ribs; further, the ova of Parosmodes   and Semalea   are somewhat flattened compared to the relatively round ova of Platylesches   , and the dorsal surface of the Parosmodes   ova is rugose. Hence, there are significant differences between these three genera as well as a striking similarity. There is a group of genera with rather similar ova: dome shaped, with fine ribs, including Erionota   , Zophopetes   , Pteroteinon   , Leona   , Artitropa   and the dicotyledon feeding genera Acleros   and Andronymus   . The similarity of the Asian Erionota   and the African Zophopetes   and similar genera is striking. Gretna balenge   differs in that the ribs are very fine and the egg shape is bun-shaped (an oblate spheroid). The two grass feeding genera, Astictopterus   and Ceratrichia   are united by smooth dome-shaped ova, without apparent ribs. The bunshaped ovum of Gorgyra   spp. differs from others, although this could be linked to its placement between leaves.

Caterpillars. The caterpillars of Hesperiinae   incertae sedis do not divide as easily into groups ( Figure 42 View FIGURE 42 ). In general, the dicotyledon feeders have stouter caterpillars, and the grass feeders tend to have more slender caterpillars. The species currently placed in Gretna   can be grouped together because of the well-developed setae and white waxy powder on the head and body. Apart from this no clear groupings can be recognised, although Semalea   and Caenides dacena   have relatively narrow heads, Parosmodes   and Melphinyet have distinct scale-like setae on the head (the similarities of the leaf shelters of these two genera have already been noted in Cock & Congdon (2013 )), Acleros   , Andronymus   and tube shelter building Platylesches   have strongly contrasting pale markings on the head, and so on.

Pupae. Representative pupae of the Hesperiinae   incertae sedis are shown in Figure 43 View FIGURE 43 . None are of the Baorini   type, which is perhaps slightly surprising since other tribes of Hesperiinae   do include genera with pupae of this type ( Cock & Congdon 2012). Possible groupings based on the pupae are not that obvious. Gorgyra   and Pteroteinon   spp. have a bifurcate frontal projection, Leona   has a blunt frontal projection, Chondrolepis   has a short down-turned frontal projection, Semalea   and to a lesser degree Xanthodisca   have a small frontal protuberance and the other genera have none; this does not seem to be a helpful character. We have noted above that the three species of Gretna   which are doubtfully congeneric have quite similar caterpillars, but the pupae are very different, implying they belong in three different genera, none of which show much affinity to any other genera. The frontal projection of the pupa of G. balenge   is unique, and the tufted pupa of G. cylinda   is also very distinctive, but this may reflect that it is the only Afrotropical species that we have documented to form its pupa on the food plant leaf without the construction of any shelter. As previously noted the pupae and pupal shelters of Parosmodes   and Melphinyet show affinities ( Cock & Congdon 2013), and the pupae of at least some Platylesches   spp. are generally similar. The pupae of Acleros   and Andronymus   show affinities in shape and colouring as well as pupal shelter construction. Above, we have noted that the pupae of Caenides   (both the palm-feeding C. dacela   and the Costaceae-feeding C. dacena   ), Semalea   , Xanthodiscus   , and Hypoleucis   are united by the broad C-shaped rim to the T 1 spiracle. The pupae of Gorgyra   and Osmodes   do not show any obvious affinities to any other genera.

The pupae of Zophopetes   , Moltena   , Monza   and Perrotia   are similar in shape and colour, while those of Gamia   , Artitropa   , and Erionota   are similar but paler. Chondrolepis   , Pteroteinon   and Leona   are also quite similar to this group, but have a frontal projection and the cremaster of Chondrolepis   is less developed and may not be functional, although this may be a reflection of a tightly rolled pupal chamber obviating the need for pupal attachment. The dicotyledon-feeding Meza   spp. may also relate to this group, but their exposed pupation site is perhaps linked to the unusual dorsal markings. The simple pupa of Acada   , which could easily be mistaken for that of a member of the Noctuoidea, might also belong with this group. The pupae of Pardaleodes   and Ankola   are of similar shape and both are very flimsy (Cock & Congdon 2014), but their shape suggests they may have affinities with this group. There may also be affinities with Kedestes   .

In summary, based on the pupae alone, we have nine possible groups:

1 Parosmodes, Melphinyet   and perhaps Platylesches  

2 Acleros   and Andronymus  

3 Caenides dacela   , Semalea   , Xanthodiscus   , and Hypoleucis   4 Zophopetes   , Moltena   , Monza   , Perrotia   , Gamia   , Artitropa   , and Erionota   with possible subgroups or related groups (a) Pteroteinon   and Leona   , (b) Chondrolepis   , (c) dicotyledon-feeding Meza   , (d) Acada   , (d) Pardaleodes   and Ankola   and (e) Kedestes  

5 Gorgyra  

6 Osmodes  

7 Gretna carmen   8 Gretna balenge   9 Gretna cylinda  

These are not incompatible with the tentative groupings suggested for the limited observations of ova. The weak groupings suggested for caterpillars are also mostly compatible except that the similarities of the caterpillars of the three species of Gretna   suggest that they are more closely related than do the very dissimilar pupae.

We look forward to seeing if and how these groups may align with future development of the classification of Hesperiinae   incertae sedis based on the T.B. Larsen’s work on male genitalia and adult characters (mostly unpublished at present) and future expansion of the recent molecular and adult character analysis ( Warren et al. 2009). In doing so, we recognise that any classification based on the early stages (and hitherto we are only considering a morphological classification rather than a phylogeny) will not necessarily align with classifications or phylogenies based on the adults, but analyses based on both combined are likely to yield a more robust phylogeny ( Meier & Lim 2009). For example, Penz et al. (2013) showed that a phylogeny based on early stages of Brassolini   ( Nymphalidae   ) was less well resolved than one based on adult characters, but that the phylogeny based on the combined dataset was similar, but not identical to that based on adult characters only. On the other hand, caterpillars and pupae living in an exposed way (as Brassolini   do) are likely to be subjected to stronger and perhaps more convergent natural selection, compared to those of Hesperiidae   , which mostly live in shelters. We have already commented on the similarity of the early stages of diverse Hesperiinae   that feed partially exposed, particularly on grasses and other monocotyledons. The caterpillars mostly have green bodies with longitudinal lines, and the pupae have similar colouring and a pointed frontal spike, which we have referred to as Baorini   type pupae (Cock & Congdon 2014). At the time we hesitated to suggest whether this was a conservative character or the result of convergent evolution to address a common problem; today we are more inclined to the later explanation. We have noted another example of convergent evolution that will obscure relationships between genera in this series of papers: the development of ‘counterfeit predator eyes’ on the heads of caterpillars and pupae which live in shelters and should gain some advantage by frightening small vertebrate predators ( Janzen et al. 2010). Thus natural selection will obscure phylogeny where selection acts to converge on particular models for life style reasons.

TABLE 2. Summary of the genera of Hesperiinae incertae sedis and their food plant families.

Genus (species) Evans’ Genera Group Food plant families1 Stages documented2 Ovum Caterpillar Pupa
Acleros   Acleros   Fabaceae   , Anacardiaceae   , Malpighiaceae   +++ +++ +++
Andronymus   Acleros   Fabaceae   , Sapindaceae   +++ +++ +++
Hypoleucis   Acleros   Costaceae   +++ +++
Meza   (sensu lato) Acleros   Fabaceae   , Linaceae   , Dichapetalaceae   + +++
Meza   (sensu stricto) Acleros   Poaceae    
Paronymus   Acleros   Dicotyledon ++
Gorgyra   Ampittia   Connaraceae   Dichapetalaceae   +++ +++ +++
Kedestes   Ampittia   Poaceae   +++ +++
Prosopalpus   Ampittia   Poaceae   +++
Astictopterus   Astictopterus   Poaceae   +++ +++
Lepella   Astictopterus   Poaceae    
Tsitana   Astictopterus   Poaceae   + + +