REPORT OF THE SOCIETY 53 



Parsnips. 



With parsnips curiously enough the solitary bees prove the most important 

 factor. Many of the species found were of large size and possessed considerable 

 powers of flight. It is interesting to note in the analysis the attraction that 

 parsnip flowers have for many insects which were not present in other seed 

 heads. 



Solitary bees 53% 



Honej^ bees 13% 



Mordellid beetles 10% 



Solitary wasps 9% 



Hemiptera 7% 



Diptera (small) 6% 



Syrphids, Cocccinellids, 2% 



Cerambycids 



I regret to say that I have no record on cabbages but I am sure that we 

 may feel quite safe in assuming that the honey bee again is a factor in cross 

 pollination of cabbage varieties. 



Sufficient has been said, however, to show that plants of different varieties 

 belonging to the same kind should not be planted close together or in the 

 immediate neighborhood. I beUeve that it is usually considered essential 

 that when commercial seed production is engaged in special seed districts 

 must be formed. All that we have demonstrated as the result of the study 

 of insect visitors to these plants is that the honey bee is a factor in each case 

 and this being a fact these seed districts must be of sufficient size to obviate 

 the danger of cross pollination. It would doubtless be necessary to create 

 legislation establishing seed areas in which certain varieties only are planted 

 and in which an earnest campaign for the destruction of allied weeds is under- 

 taken. In every instance with the insects mentioned in this paper, pollen 

 grains were found on the bodies. Syrphid flies were numerous and, as you 

 doubtless know, are clothed with long dense hairs which are usually simple 

 though frequently curved at the tip.. These hairs form an excellent trap 

 for pollen grains. Some species such as Eristalis tenax have compound branch- 

 ing hairs. Their movements on the wing and on the flowers are erratic standing 

 while on the wing over selected blossons before settling. Many members of 

 this group are strong and active in flight and doubtless cover considerable 

 distances, but their method of blossom visitation is not systematic enough 

 to cause them to be of great concern to plant breeders. Adults may be seen 

 frequently freely visiting plant after plant in a single stand but have been 

 observed to visit, just as freely, plants in bloom of different botanical families 

 in the immediate neighborhood. They do not hesitate after visiting the 

 blossom of a plant to settle on the leaves of neighboring plants^ which excrete 

 sweet exudations. Currant leaves appear to prove a strong attraction and 



