Cheilomenes lunata (Fabricius, 1775)

So what group of beetles is not significantly more valuable to agriculture than the average beetle group but is much more widely tolerated and, for an insect, even loved across the western world?

I'll give you a hint.

Photographed in Chongwe, Lusaka, Zambia, in February 2013. Olympus E-420 DSLR, Zuiko 40-150mm digital lens with 3 KOOD magnifiers.

Yes, it's a ladybird. Specifically, the (African) Lunate Ladybird,

Cheilomenes lunata

(Fabricius, 1755)

 

 - Coccinellini
- Coccinellinae
- Coccinellidae  
 - Cucujoidea         
 - Cucujiformia         

See also Otiorhynchus atroapterus.

- Polyphaga                

See also Malachius bipustulatus and Melolontha melolontha.

- Coleoptera                   

See also Demetrias atricapillus and Anthia fornasiini.

- Coleopterida                   
- Endopterygota                    

See also Crambus pascuella, Hagenomyia tristis, Astata tropicalis, Vespula germanica, Synagris proserpina, Zebronia phenice, Laelia robusta, Anthocharis cardamines, Acada biseriata Panorpa germanica, Megistocera filipes, Senaspis haemorrhoa, Episyrphus balteatus, Helophilus pendulus, Diasemopsis meigenii and Dolichotachina caudata

- Eumetabola                                  

See also Pephricus, Anoplocnemis curvipes and Ranatra

- Neoptera                                          

See also  Sibylla, Stictogryllacris punctata, Lobosceliana loboscelis and Cyathosternum prehensile

- Manopterygota                                     

See also Rhyothemis semihyalina, Pseudagrion hageni and Enallagma cyathigerum

- Pterygota                                                  

- Dicondylia                                                  

- Insecta                                                            

- Hexapoda                                                           

- Arthropoda                                                            

See also Ligia oceanica, Dicranopalpus ramosus, Enoplognatha ovata, Argiope bruennichi and Hyllus argyrotoxus.

- Ecdysozoa                                                                 

- Protostomia                                                                  

- Nephrozoa                                                                      

See also Burhinus vermiculatus, Chiromantis xerampelina, Thelotornis capensis, Trachylepis varia, Lygodactylus capensis, Ardea goliath, Chalcophaps indica, Sterna hirundo, Synchiropus splendidus and Hipposideros vittatus.

- Bilateralia                                                                            

- Eumetazoa                                                                              

- Animalia                                                                                     

- Eukaryota                                                                                       

Why are ladybirds so much popular than, say, the Carabidae, which are just as active, if not more so, as predators, and have generally higher metabolisms, demanding that they chow down more pest insects? 

I'd suggest that it's actually about toxicity. The ladybirds are often brightly coloured, advertising that many of them have fairly nasty poisons in their systems, which any sensible vertebrate would do well to avoid. Defended so visibly, many of them are active during the day and, being conspicuous, are much more likely to be observed chowing down aphids than a night-active beetle with a similar diet. As a result of this, one might expect them to earn a reputation for helpfulness.

But this is just speculation. What is true, though, is that Ladybirds have been introduced to farms all over the world, and in many cases wreaked havoc upon the native ecosystems - from the seven-spot ladybird (Coccinella septempunctata) introduced to the Americas from its native Europe, and now devastating beetle life stateside, to the harlequin ladybird (Harmonia axyridis), which has been destroying the seven-spot (and other local species) ever since it was introduced from the Far East. 

The short version: Ladybirds are great, so are many beetles. Setting them free in new environments is not great. At all. 

That's all, folks!