Beetledude's Notes & Tips, No 1: Searsia Flea Beetles

 
COLEOPTERA: CHRYSOMELIDAE: GALERUCINAE: ALTICINI

Searsia Flea Beetles: Calotheca and Blepharidina

The concept of the genus Blepharida (Rhus Flea Beetles) is now confined to the New World (plus some presence in Eurasia), as had been suspected for some time. This change was in 2016 properly motivated and formalised IN HERE. What we used to know as "Blepharida" in the Afrotropical Region are species now placed in the two GENERA Calotheca and Blepharidina, the latter genus with two subgenera, Blepharidina (Blepharidina) and Blepharidina (Afroblepharida).
 
 

◘ The genus Calotheca is widespread through sub-Saharan Africa, especially in the southern and eastern areas, but one species penetrates to Arabia and Palestine. The preliminary species count for Calotheca is 27, with 21 species in southern Africa. ◘ The genus Blepharidina occurs in the intertropical area of Africa.

• Blepharidina s. str. is mostly distributed from CAR/DRC in the north towards the south of the intertropical area, as far south as the Zambezi River valley, plus in Mozambique down to the very south, which makes one expect it to be found in e Zimbabwe, Swaziland and ne South Africa as well.
• Blepharidina (Afroblepharida) occurs largely in the central eastern intertropical area with some spread to West Africa, i.e. from Somalia/Kenya to Burkina Faso, but always north of the Congo Basin, and to its east in Uganda & Tanzania.

Revision at genus level was completed first, by Biondi, Frasca, Grobbelaar & D'Allessandro (2016).
Revisions at species level are presently continuing.
Already published is the revision of the subgenus Blepharidina (Afroblepharida), by D'Allessandro, Frasca, Grobbelaar, Iannella & Biondi (2017).
 

CORRECTION TO PGW2004
If you use the South African insect field guide by Picker-Griffiths-Weaving (2004), make the following correction. Use a pen.

►PGW2004: 250.2 shows one of these beetles, necessarily as the genus Blepharida. Change that to Calotheca. May as well update the English common name to 'Searsia Flea Beetles' also, since Rhus was taxonomically banished from the Afrotropics even before the insect guide was published. Karee is Searsia.

HOST PLANTS

Although they are called Searsia Flea Beetles, these insects have other hostplants also, depending to a great extent on the species of beetle. Calotheca species have been recorded from the following plant genera:

Anacardiaceae: Searsia (usually recorded as Rhus), Ozoroa, Schinus. Burseraceae: Commiphora.

Absolutely no hostplant information exists for Blepharidina (Afroblepharida). The information for Blepharidina s. str. has not been published yet.
 
It is expected that at least some of the beetle species will be host-specific to at least a number of hostplant species, and one-to-one relationships are not impossible. But there are too little information to make any conclusions. Citizen scientists (YOU!) can contribute greatly to this by recording (with picture-proof) the plants on which you found any beetles that you contribute to iNaturalist. With this series of revisions progressing rather well, it will soon become possible to identify these large flea beetles to species level. At last!
 
 
 

Key to the Searsia Flea Beetle genera

A key to tell Calotheca from Blepharidina, and the two subgenera of the latter, apart on good photographs.
 
This key is based on that of Biondi &al (2016), but for Blepharidina I rather severely modified it following new information published by D’Alessandro &al (2017).
 
An instructional, educational, reasonable, justifiable, legitimately used copy of the figures referred to in the key can be found below. In case of an attack by the Avaricious Press Police, the pictures are also safely placed OVER HERE.
 
 
1.     Frontal grooves on head elongate, sinuate, and deeply impressed; extending from upper eye margin to distal margin of antennal protuberances (Fig. 2). Clypeus not depressed (Fig. 2). Pronotum with two striae formed by some large and deeply impressed punctures running from anterior pronotal margin towards pronotal disc, sometimes L or C shaped (Fig. 4). Pronotal punctation mostly homogeneous and uniformly distributed (Fig. 4). Distribution throughout the Afrotropics ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... Calotheca ...... ..... CLICK!
 
––     Frontal grooves on head short, generally very slightly impressed (Fig. 1). Clypeus depressed (Fig. 1). Pronotum with more oblique, transversally or vertically-oriented striae of large punctures (Figs. 5, 6). Pronotal punctation clearly non-homogenous and distributed in patches (Figs. 5, 6) ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... 2
 
 
2.     Lateral margin of pronotum in lateral view regularly rounded. Both anterior and posterior margins of pronotum narrower medially than laterally. Base of pronotum with two small lateral dimples. Elytral punctation in double rows or bands or mostly irregular. Distribution east & north of the Congo Basin ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... Blepharidina (Afroblepharida)
 
––     Lateral margin of pronotum in lateral view distinctly sinuate. Both anterior and posterior margins of pronotum wide, sometimes wider medially than laterally. Base of pronotum with two lateral longitudinal striae. Elytral punctation in single, regular rows. Distribution from northern Congo to Angola and through Tanzania to southern Mozambique, not yet recorded from Zimbabwe, Swaziland or South Africa ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... Blepharidina (Blepharidina)
 
 

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Version 1. 2018-03-12.
Version 1.1. 2018-06-24.

Julkaistu maaliskuu 12, 2018 12:15 AP. käyttäjältä beetledude