Jnue, 1911.] Pollination Notes. 379, 



erence to various structures of some of the Cedar Point plants 

 upon which insect -visitors were collected. Most of the insects- 

 observed were members of the following orders, namely: Diptera,, 

 Lepidoptera, Coleoptera, and Hymenoptera. 



We will now take up a consideration of some of the character- 

 istics of a few of the summer-blooming plants of Cedar Point and 

 note some of their insect -visitors. These studies were carried on 

 under the direction of Mr. O. E. Jennings, Instructor in Ecology 

 during the term of 1910. 



Nymphaeaceae (Water Lily Family). 



"The large floating flowers are protected from creeping ani- 

 mals by their aquatic habitat, and are only accessible to flying 

 insects. The inner side of the sepals is colored like the petals, so 

 that both whorls are conspicuous. A more or less distinct odor 

 of honey also serves as a further attraction to insects."^ 



Castalia tuberosa. "The faintly odorous large white flowers 

 which open in the morning and close towards evening are homo- 

 gamous, according to observations. Kemer states that the 

 stigmatic papillae are mature at the beginning of antithesis, 

 remaining receptive for several days. The anthers dehisce a day 

 — or rarely a few da^^s — later. Tlie filaments bend into the form 

 of a siclde, so as to bring the anthers above the stigmas, which 

 spread out into a plate-like surface so that self-pollination must 

 result from the falling of pollen. Insect visitors may effect either 

 cross- or self-pollination, but they are few in number."-^ 



Visitors: Diptera; EristaJis flavipes. 

 Nymphaea advena. This water lily also may be self- or cross- 

 polHnated. The visitors taken are as follows: 



Visitors: Diptera; Mesograpta marginata; Coleoptera; Dona- 

 cia pus ill a. 

 Nelumbo lutea. Sprengel says: "The increased size and yel- 

 low color of the upper surface of the sepals have taken on the 

 function of the corolla, and the under sides of the petals secrete 

 honey" which serves to attract insects. 



Visitors: Diptera; Allograpta obliqua, Eristalis teiiax, Meso- 

 grapta marginata; Coleoptera; Disonyca penn- 

 syhaniea, Diabrotica 12-punctata; Hymenoptera; 

 Microbembex monodonta, Agapostemon radiatus. 



Malvaceae (Mallow Family). 

 Hibiscus moscheutos. This plant is quite conspicuous on the 

 edge of the marsh and with its pink or whitish color and its abund- 

 ance of pollen proves attractive to certain insects. Insect vis- 

 itors are essential to pollination since the stigma is slightly above 



20p. cit., II. 59. 

 »0p. cit., II. 59. 



