Beetledude's Notes & Tips, No 2: Those small, black, white-spotted fruit chafers

 
COLEOPTERA: SCARABAEIDAE: CETONIINAE: CETONIINI: CETONIINA
 
 

Those small, black, white-spotted fruit chafers: Genus Cyrtothyrea

••• SOUTHERN AFRICA ONLY •••

 
 
In their fieldguide, Picker, Griffiths & Weaving (2002, 2004) made Cyrthothyrea marginalis famous as the Common Dotted Fruit Chafer (PGW2004: 200.4). Nothing wrong with that, but what about all those other Cyrtothyrea species? They all look the same if you do not have secret information. Here is some of that secret information.

First, four things should be noted:

    ○ Cyrthothyrea is a difficult genus.
    ○ Cyrthothyrea is an unrevised genus (one of only two southern African fruit chafer genera without a modern treatment).
    ○ These notes and keys are complete for southern Africa only. Further north there are more species, and a lot more confusion.
    ○ There are more small, black, white-spotted fruit chafers in other genera, however less likely to be encountered. Notes to follow maybe someday.

 
 

Two subgenera

Some experts split the species of the genus Cyrthothyrea into two subgenera, which is useful, but only in southern Africa. This is a tentative arrangement, but thank goodness for these subgenera! They are:

      (1) The nominotypical subgenus, Cyrtothyrea (Cyrtothyrea), and
      (2) Subgenus Cyrtothyrea (Manodema).

In the iNaturalist dictionary these subgenera are not indicated. Click on 'Taxonomy' HERE to see the species of the genus. And here is a quick summary of which species belong to which subgenus:

    Subgenus 1: Cyrtothyrea (Cyrtothyrea) Cyrtothyrea albomaculata Cyrtothyrea marginalis Cyrtothyrea testaceoguttata Subgenus 2: Cyrtothyrea (Manodema) Cyrtothyrea rubriceps Cyrtothyrea ruficeps

 
 

Simple key to the two subgenera of Cyrtothyrea

Obviously this little key will only work when the necessary detail is in focus, which will be most of the time not. Don't get a fright!:
    ○ The orange or red on the head of the second subgenus is conspicuous.
    ○ The second subgenus is tropical, reaching southern Africa only at its northern limits. For almost all Cyrtothyrea from South Africa this subgenus (Manodema) may be disregarded as an option. Moreover, species of subgenus Manodema are all much less spotty than the Common Dotted and the Another Dotted Fruit Chafers that are well known and well represented on iNaturalist.
 
► Clypeus, antennae & pygidium black, remainder of integument black with white spots; one species with anterior margins of pronotum reddish; some specimens with entire integument reddish brown instead of black ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... Cyrtothyrea (Cyrtothyrea)
 
► Clypeus, antennae & pygidium yellowish orange to reddish, remainder of integument shiny black; with white spots ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... Cyrtothyrea (Manodema)

 
 

Subgenus 1: Cyrtothyrea (Cyrtothyrea): species

Three species::

  1. Black (or sometimes reddish brown) with a lot of small or smallish white spots. Occurs in South Africa ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... go to 2
     
    – Black with a smaller number of medium-sized to fairly large white spots. Central Mozambique to Tanzania ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... East African Dotted Fruit Chafer – – Cyrtothyrea albomaculata.
     
     

  2. Lateral margins of pronotum always reddish brown ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... Common Dotted Fruit Chafer – – Cyrtothyrea marginalis.
     
    – Lateral margins of pronotum with white stripe, which may be broken ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... Another Dotted Fruit Chafer – – Cyrtothyrea testaceoguttata.

 
 

Subgenus 2: Cyrtothyrea (Manodema): species

Two species::*

  1. Lateral margins of pronotum with one or two white spots; disc of pronotum with a pair of rows that each consists of three spots or flecks. Central Africa, south to central and eastern Zimbabwe and central Mozambique ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... Cyrtothyrea ruficeps.
     
    – Lateral margins of pronotum with zero to three white spots; disc of pronotum without spots. Zambezi Valley; Zimbabwe/Mozambique border (mountains); southern Mozambique & northern KZN (coast & lowlands) ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... Cyrtothyrea rubriceps.
     
     
    No examples of Cyrtothyrea (Manodema) on iNaturalist yet. As of today.

*Cyrtothyrea (M.) pygidialis has been excluded deliberately.

_____________________
Version 1. 2018-05-06.

 
 
If you are one of the fortunate people who own a copy of the "Blue Book" (Holm & Marais 1992, Fruit Chafers of Southern Africa), please note:
There are a significant number of mistakes in the illustrations published, the corresponding names, the corresponding figure numbers, and the figure references in the text, concerning the genera Cyrtothyrea and Leucocelis (Plates 28–30).

 
 
Did you know that there is a huge and brand new book with colour photos of all the fruit chafers of the Afrotropical Region? Detail (review maybe?) in a future posting. I'm still saving for my copy. It weighs a lot of money.
 
 

Anotado por beetledude beetledude, 06 de mayo de 2018 a las 02:40 AM

Comentarios

Great key !. More keys please !

Anotado por botswanabugs hace mas de 3 años (Advertencia)

Do you ever sleep! Just so great collecting all of this info from you Riaan.. have a separate referencing file (Beetledude's notes & tips)

Anotado por fayneconnelly hace mas de 3 años (Advertencia)

Thank you very much! (This information also weighs a lot, it can not be measured in money!)

Anotado por cheekychew hace mas de 3 años (Advertencia)

Thanks Riaan. i've made a request that a link to these notes go under the "About" page on the species https://www.inaturalist.org/flags/234156

Anotado por vynbos hace mas de 3 años (Advertencia)

And there they are, @vynbos -- thank you for the idea:

https://www.inaturalist.org/taxa/489498-Cyrtothyrea >> About >> More Info.

Anotado por beetledude hace mas de 3 años (Advertencia)

Thanks Im also saving !

Anotado por botswanabugs hace mas de 3 años (Advertencia)

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