566 



T-mm MMSMiC'Si* m,mm j@^mMmi^, 



The foregoing information is from 

 the early volumes of the American 

 Bee Journal. Other papers may 

 add more light. It was a surprise to 

 me to see how little was said in regard 

 to these important improvements. 



Other problems that we call new to- 

 day, were advocated fifteen or twenty 

 years ago. 



East Saginaw, Mich. 



MILK-"WEED. 



Bees Loaded Avitli Pollen Masses 

 from It. 



From the Farm, Stock and Home. 



Chas. Koonze, of Faribault County. 

 Minnesota, writes the Editor as follows: 



Can you tell me through jour paper 

 what is wrong with my bees ? They 

 have done splendidly till the last few 

 days ; they now seem entirely engaged 

 in fighting, and thinking that robbers 

 were bothering them, I reduced the 

 size of their entrance, and in so doing 

 I noticed the bees that thej' were at 

 war with, had peculiar legs. Catching 

 a few, and picking up a few dead ones, 

 and putting them under a magnifier, 1 

 saw their legs seemed loaded with 

 what appeared to be the eggs of some 

 insect. I send jou a box by mail, en- 

 closing a few bees, and also some dirt 

 which I picked up in front of the 

 alighting-board. Give a remedy if 

 you can. and oblige. 



Prof. N. W. McLain, director of the 

 Minnesota Agricultural Experiment 

 Station, by request, replies as follows : 



The bees sent are loaded with pollen 

 masses from milk-weed, and the dirt 

 accompaujdng is chiefly composed of 

 the same material. The poUinia and 

 attaching bands often accumulate on 

 the feet and hairs of the legs of the 

 bees to such an extent as to render 

 them helpless. The efforts of the bees 

 in assisting their mates to extricate 

 themselves was proliably mistaken by 

 your correspondent for fighting. The 

 strength and efficiency of a colony is 

 often seriously injured from this cause. 

 The remedy is to destroy the milk- 

 weeds within reach of the bees. 



I have asked Dr. Luggar, entomolo- 

 gist of the Station, to make a drawing 

 and write a short explanation of how 

 this mishap befalls tlie hees when they 

 are seeking for nectar, and also per- 

 foi-ming the function of fertilizing the 

 flowers. His rejily is submitted here- 

 with : 



AscLEPiis AND Bees. — There are 

 few genera of plants which rival the 

 orchids in the complexity of their per- 



fect adaptation to insect visitors. The 

 species of our common milk-weeds 

 (Asclepins) belong to such genera, 

 but their mechanism is so complex 

 that it is impossible to describe its 

 adaptation to the purpose of forcing 

 insects to fertilize the flowers, without 

 giving at the same time some illustra- 

 tions. To understand the tiiodics oper- 

 andi the readers should pick to pieces 

 one of these flowers and thus learn it. 



The two ovaries are surrounded by a 

 flesh column (Fig. 2, in), and covered 

 by a thick, fleshy disk, and they are 

 only capable of fecundation at five 

 stigmatic spots close beneatli the lower 

 border of the disk (Fig. 1, o). The 

 column, which really consists of the 

 united starainal filaments, bears at its 



Asdepias or Milk- Weed. 



upper end five anthers. The anthers 

 lie close around the stigma-disk ; each 

 of them lodges two flattened pollen- 

 masses (Fig. 2 i, and3)intwo pouches, 

 which are open internally, and are in- 

 dicated externally by slight swellings 

 (Fig. 2, d). 



A thin membraneous pi-ocess of the 

 antiier (Fig. 1, c) rests upon the top of 

 the stigma-disk, and on each side the 

 anther is produced into a triangular 

 membraneous expansion or wing (Fig. 

 1, e), which stands out perpendicular 

 to the column close to the correspond- 

 ing process of the adjacent anther. 



Between the two adjacent processes 

 of each pair of anthers, there is left 

 only a very narrow slit, which is dis- 

 tinctly wider at the lower end (Fig. 2, 

 /). The slit leads into an elongated 

 space which we may call the stigmatic 

 chamber (Fig. 2, o), for about the mid- 

 dle of its vertical height the stigma is 

 exposed. At the upper end of the slit, 

 visible from the outside, is a bright, 

 black body of regular shape (Fig. 1, g 

 and Fig. 2, g), which is seen on closer 

 examination to be a thin, hard, horny 

 lamina. The sides are bent forward 

 for its whole leugth so that their edges 

 lie close together, and in the middle of 

 the lower border is a wedge-shaped 



slit. To this lamina (g) the two adja- 

 cent pollinia of 2 neighboring anthers 

 arc attached by bands which lie hidden 

 beneath the anthers (Fig. 2, h and Fig. 

 3). The upper end of the column car- 

 ries, besides the five anthers, five hol- 

 low, fleshy organs, which secrete a 

 large quantity of nectar. | 



This singular appai'atus acts in the j 

 following way : Insects, (bees, wasps i 

 and flies) in search of honey, attracted I 

 by the sweet scent of the flower, slip ' 

 upon the smooth parts of the flower 

 until a foot enters the wide inferior 

 part of the slit, in which at least it gets 

 a firm hold. When the insect tries to 

 draw its foot out, in order to proceed 

 further, the diverging claws are caught 

 by the opposed edges of the anther- 

 wings, and guided upwards in the slit. 

 so that one or the other of the two 

 claws is brought without fail into the 

 notch at the lower border of the black J 

 lamina (g) and there held fast. If the 9 

 insect now draws its foot forcibly out, 

 it brings with it g. the two pollina (i) 

 attaclied to it by their retinacula (h). 3 

 The pollinia stand wide apart when 1 

 the}' are extracted ; but the retinacula 

 twist inwards as they dry, bringing the 

 pollinia so close together that they maj' 

 easily be introduced into anotlier .slit. 

 As the insect moves on over the flowers, 

 its foot bearing the pollinia slips into 

 the lower part of a slit of another 

 flower ; and this time, as the leg is 

 drawn up, the pollinia are left in the 

 stigmatic chamber opposite to the .stig- 

 ma, since the slit is too narrow to 

 admit of their further passage up- 

 wards ; and the insect, freeing its foot 

 by a violent pull, snaps the I'etinacula, 

 and so extricates itself. The pollinia 

 are left behind in the .stigmatic cham- 

 ber, while the broken retinacula is 

 carried oft" still tirmlj' attached to the 

 insect's foot. 



The insect continues its visits, and 

 the retinacula attached to its feet now 

 gets fixed in g. as the claws did before, 

 and an insect's foot, after repeated 

 visits, may sometimes be bearing many 

 pollen-masses, as seen in Fig. 4. 



Frequently insects are unable to 

 withdraw their feet, and they die in 

 the attempt to do so. I have often 

 .seen blow-flies, small moths, and even 

 week honey-bees thus captured. 



The well known Physianthtis albens of 

 Australia is a climbing species of milk- 

 weed ; it is often sold % gardeners, 

 because it has the habit of catching 

 and holding even large insects in the 

 same manner as our native species of 

 milk-weeds. Otto Ldggar, 



Entomologist. 



Simniins' j^on-SwamiinR- Sys- 

 tem, and the Amkrican Bee Jouknai, 

 for one year, for Sl.3.5. The subscription 

 to the Bee Journal may begin now. 



