X. s 
- 19 - 
Missouri 
Idaho 
L. Baseman. -(li?.rch_ !&)■'. We have had an "unusual hoavy ran on com- 
plaints a^orat~-t^- xoatifO 112* thi« -winter in which they refer to 
last summer's ^viasis. We are expecting trouble over the corn 
"belt ox the State a L ^in this summer. 
ALFALFA 
ALFALFA T7EEVIL ( Phytonomus posticus Gyll.) 
University of Iiaho News Letter, Moscow, Vol. XII, No.. 2 (February 
24): In a few localities in Idaho the belief seems to prevail 
that the alfalfa weevil has suddenly died out and that no further 
injury will be done "by it. This "belief has "been occasioned "by 
the fact that in 1924 the amount of damage caused "by this pest 
was much less than in 1923, and it has "been formed without a 
knowledge of the contributing factors of the weevil itself. During 
the past two years the experiment station entomologist has kept a 
close check on the development of the alfalfa weevil in southwest 
Idaho, and the station is in a position to draw a comparison be- 
tween the two years mentioned. By daily observations and careful 
counts data were obtained each year which are assembled in the 
form of a table of comnarisons as follows: 
Comparison of 1923 ard 1924 
First worms found 
Date when injury began to be severe 
and generally noticeable.-. . . . 
Date when greatest number of worms 
occurred in the field 
Greatest number of worms collected 
in 100 strokes of the insect net. 
Period during v;hich numbers of worms 
and amount of injury increased. . 
Time after first spray application 
\intil greatest number of worms 
was reached 
1923 
May 7 
May 23 
June 22 
5010 
46 days 
30 day3 
1924 
May 1 
May 17 
May 25 
7564 
24 das 
5 days 
Difference 
(Days) 
6 
28 
22 
25 
Climatic conditions for the two years were quite different. A 
late spring and a cold, wet May and June characterized 1923, while 
the hot, dry spring and early summer of 1924 are still fresh in 
the momory of most who were engaged in farcin;.:. From the time 
that worms become numerous enough to cause injvtry until they have 
reached their greatest numbers and stoppod feeding is the critical 
period in relation to the amount of damage done. Studying the 
above table disclosed the fret that the greatest number of worms 
in 1924 occurred 28 days earlier than in 1923, and that injurious 
numters fed on the first crop for 22 days less than in 1923. In- 
stead of fewer weevil than in 1923, there vr^re actually more in 
the field at one time in 1324, but they attacked the plants at a 
different stage of growth and fed for a shorter period of time. 
