. 3— SOME OBSERVATIONS ON ENTOMOPHILOUS 

 FLOWERS. 



By R. Marloth, Ph.D., M.A. 



Of the three principal agents upon which plants depend for 

 cross-pollination, viz., the wind, the birds, and the insects, almost 

 nothing is known as yet about the role which the last named visitors 

 play in this respect in South Africa. 



A little more has been done in recording such observations with 

 regard to the birds, the number of flowers which are known to be 

 ornithophilous being already very considerable, although the list is 

 far from complete. My records comprise twentv generi from 

 various families. The more common of these are 

 MeliattiJius, Cotyledon, Rochea, Erythrina, Erica, Duvcrnoia, 

 Tecomaria, Lconotis, Salvia, Sclago, Protea, Tieucosfcrnuim, 

 Mimetes, Loranthus, Strelitzia, Aloe, Knifhoiia, Lachenalia, Wat- 

 sonia, Antholyza, Gladiolus, and Bahiana. 



On the other hand, in spite of the floral wealth for which 

 South Africa is famous, the insect-life, which depends upon flowers 

 for its sustenance, has received little attention ; at least, apart from 

 a few stray notes, almost nothing has been published on the subject. 

 European botanists seem to think, that this is principallv due to 

 the indifference of South African observers. To some extent that 

 may be so, but there is another remarkable feature of the subject, 

 which is largely responsible for this lack of information in South 

 Africa. 



Local botanists as well as entomologists have repeatedlv noticed, 

 that often there seems to be an entire absence of insect life, although 

 the fields or the hillsides may be aglow with flowers. 



One may sometimes wander about for hours among thousands 

 of flowers of Oxalis, Mesemhrianthemum, Arctotis, Dimorfhotheca, 

 Cry-ptostemma, Gazania, and many others, without discovering 

 a single visitor. There are some species of most common occurrence 

 in the South-West, as e.g. Belmontia cordata (E. Mey), a little 

 spring annual with bright golden stars, on which I have never seen 

 a single insect as yet, although I have w-atched thousands 

 of its flowers every year. Everyone knows the beautiful 

 blue Disa {D. graminifolia, Ker), which appears at the end of 

 summer on the south-western mountains in enormous numbers. 

 Although I may have seen hundreds or thousands of its flowers every 

 year, I have, in the course of 20 years, only on three occasions 

 observed an insect actually visiting the plant. 



On the other hand, there are some kinds of flowers which form, 

 so to say, regular food-depots for bees and other insects. The 

 various kinds of aloe, which mostly flower in w'inter and spring, 

 are often swarming with bees, and the beekeepers of the aloe dis- 

 tricts, or the natives who watch the nests of the wild bees, secure 

 an ample harvest of honey at that season. 



It will be best for us to arrange the few observations that have 

 been recorded according to the natural orders of the plants. 



