76 The Botanical Gazette. [February 
in different regions in cases in which the insects have been 
identified: 
2 le 1 os <4 
< & % r] 
jal | jel & 
a s| 2 6} js) al: 
C8 Be foie 
Sauix. REGION. OBSERVER. a = % |e # | 8 z x |e 
25) E exlelslsl elk 
2710 lO" |4/<|n| 0 6 
cordata..... Illinois 49| 38 7| 8|28j21) 18) § 
humilis ..... Illinois 24} 5] 3/20] 7) 9 7 
cinerea ... 
caprea .... Germany..} Miiller(6,12,17)..| 61] 52 g|t9|44|17} 16 ! 
aurita 2s 
cinerea ..... Germany..| Loew (20)........ I I EL] Te efeeeefen 
capreay.'3% Germany..| Loew (28)........ I! 5 «| 4{ta}..} Bee 
aurita cies ermany..| Loew (20, 28)..... I 2 | alee) pene 
nigricans Germany..| Loew (20)........ I I 1} Heels cenee 
Wve. oe. ermany..j Loew (28). .......<|...- I |.cleafee) ee 
amygdalina..| Germany..| Loew (28)........ I I]. eJeeees 
amygdalina. .| Germany..| Miiller (12)....... 2 3). 0-6] 3] Aho oe 
fragilis ..... rmany iiller (12)....... 2] al st} | 2f..fere 
rmany..| Miiller (6, 17) 4-6) °° 3) 2 aie { 
£2 Soke orderney| Verhoeff (26).....{ 7] 26) 2 4} 1| 6| 14 : 
Early spp Flanders. .| Mac Leod (27) 15| 28) 5} 6|12) 3} 1 
Late spp landers. .} Mac Leod (27 71 5}----| 13, 4 ee 
ea. Ps Miiller (15, 17) E aie, AIA ae ip 
reticulata Alps...... iiller (15) ears rl 
as eek Alps......} Miiller a ESR rd atone @ I Il.alexherlereeeae 
_ienenea ee 
Those species which bloom before the leaves appear—@ i 
the two following cases—are more abundantly visited becaus 
they have fewer competitors, and because their flowers a 
less concealed by the leaves. 
SALIX CORDATA Muhl. blooms from March 18th to Apt 
23d. On April 9-11th, 14th, 17th, 18th, and 2oth the follot 
Ing insects were taken on the flowers: Osmis 
YMENOPTERA—Afide : (1) Ceratina dupla Say ¢, Sy freq.; (2) ala . 
= ides Rob’ 
on 8%, S.,very ab.; (5) N. luteola Lep. ,49 s., ab.; (6) N. luteoloides ar 
m. 4, s.; (8) N. integra Rob. 39, s., ab.; 4” 
de: (9) Andrena erpaecnunlee Reais 89, “4 and c. p., ab., in COP» ( 
“ 
~I 
= 
f> 
“ 
a 
oO 
oc 
pet 
f 
co 
f 
wm 
d (I 
i 49, s., ab.. in : b. 49, s. and ¢. Ps 
A. illinoensis Rob. 69, s one cs eee abe 13 ye 
Sm. 62, s., ab., in ¢ - Cressonii Rob. 4, 15) A . (8 
b. 2, S.; (16) A. rugosa Rob. 82, S.; (17) rythronii Rob. Pe 
A. forbesii Rob. 9, s.; (19) A hippotes Rob. 4, s.; (20) A. marl& 
; 8.5 oat 
s. and c. p., ab.: in cop.; (21) A. claytonie Rob. 9, s., ab.; (22) &\® 
dibularis Rob. 4, s.; (23) A. pruni Rob. 8; (24) Panurgus? andrent”” = 
