109 



It has a very large distribution in America, and large areas 

 overgrown with this plant are not unusual. The leaves are 

 similar to the Mimosa, and the yellow and orange red blos- 

 soms are collected in an open pyramidlike bunch on the 

 top. The Shells are sickleformed and it is in all probability 

 this, that has given the plant the common name in Men- 

 doza of the „little field (or „camp") bean". 



Personally I do not believe that there is a plant in the 

 whole of the Western Argentina that is more visited by bees 

 than Hoffmanseggia falcaria, which can be seen in blossom 

 throughout the whole of the Argentine summer, to say 

 nothing of its being thornless and easy to get at. It is only 

 necessary to come to a Stretch of this plant in flower and 

 stand a little to one side with net ready to take all that 

 come within ränge, and with still weather and clear sunshine 

 a great number of bees can be taken. No Entomologist can 

 imagine a more profitable and enjoyable employment than 

 collecting bees on Hoffmanseggia, the only irritating thing 

 being that it is impossible to collect all that you can see, 

 and while bottleing one good bee, another still better flies 

 off to a neighbouring Hoffmanseggia place. 



In Knuth's „Handbuch der Blütenbiologie" some species 

 of bees are mentioned as visiting Hoffmanseggia falcaria. 

 As the list, however, is proportionally small, it would seem 

 to show that no special attention had been paid to the 

 insects that visit this plant, as alone in the Mendoza district 

 the number of bees that come to Hoffmanseggia would 

 reach well up to fifty, and if a thorough investigation in all 

 ihe districts, where the plant occurs would take place, the 

 list of bees that come to Hoffmanseggia falcaria would 

 certainly reach up to several hundreds. 



It is chiefly the females that visit the flowers, although 

 with several species the males are energetic workers, for 

 example Melissa Jenseni, Teiralonia flavitarsis and still 

 more so with Tetralonia corvina. A. Ducke from Para men- 

 tions in „Zeitschr. f. wiss. Insektenbiologie" for 1906 that 

 „auf den wohl nur Pollen liefernden Blüten" from Hoff- 

 manseggia (Cassia Hoffmanseggia) only the females of the 

 genus Centris are met with. This, however, is only for the 

 Para district, but from my experience it does not suit the 

 Mendoza district. Ducke further mentions in the same paper: 

 „Bezüglich des Besuches verschiedener Blüten durch die 

 einzelnen Geschlechter einer und derselben Bienenart ist 

 zu erwähnen, das die $$ vieler Bienen einige Pflanzen des 

 Honigs, andere des Pollens wegen aufsuchen. Auf ersteren 



