56 EXPEEIMENT STATION EECOED. 



varies from 5 to 62. The eggs hatch in from 10 to 16 days, depending largely 

 on temperature. Larval life lasts from 5 to 40 months or more. The time 

 of pupation is from 11 to 17 days. The age of adults varies from 10 to 32 

 days." 



Biological record of little grass billbug (Sphenophonis parvnlus), R. I. 

 Smith (North Carolina Sta. Rpt. 1912, pp. 136-140).— Two hundred and fifty- 

 five eggs were laid between May 19 and October 7, a period of 142 days. Seven 

 eggs was the greatest number laid in any 24 hour period. The female was alive 

 and healthy on October 27, when daily observations were discontinued ; and 

 was still alive but lying buried in the soil on November 20 when last seen. 

 The average incubation period proved to be about 7 days during the early 

 days of June, and about 6 days during July and August. During the last of 

 September, when much cooler weather prevailed, some eggs took fully 11 days 

 to hatch. The larv^al stage for the 7 si)ecimens recorded varied from 31 to 

 &) days, a condition which the author believes to be comparable with normal 

 field conditions. The pupal stage covers about 9 days, dependent somewhat 

 on heat and moisture conditions. Moisture, however, does not seem to be as 

 necessary as warmth, for some of the pupa developed normally in a very dry 

 cell. A second generation may occur if the proper conditions prevail. 



[Report of work with the com billbug ( Sphenophorus callosus)], R. I. 

 Smith (North Carolina Sta. Rpt. 1912. pp. 105-135). — In continuation of pre- 

 liminary investigations of the corn billbug, previously noted (E. S. R.. 26, p. 

 862), the author presents a detailed account of studies of its life history and 

 habits, which he finds to be as follows: "Eggs are first laid about May 20 In 

 com plants or the larger species of Cyperus and possibly in other sedges. 

 The eggs require an average of 6 days for hatching. Egg laying continues until 

 the latter part of September. The larvaa feed in the stalk or root of the plants 

 and become full-grown in an average period of about 33 days. Larvae of all 

 ages occur from June to after November 30, but the majority are full-grown 

 before November 1. The pupa? occur in cells in the stalk of the food plant 

 or in the soil underneath the roots. Nine days is the average duration of the 

 pupal stage. The beetles mature and usually emerge and feed during the 

 months from July 1 to November 1 or later. These beetles do not often mate 

 and lay eggs until the following spring, after emerging from hibernation." 



Notes on Lixus concavus, H. B. Weiss (Jour. Econ. Ent., 5 (1912), No. 6, 

 pp. JfSJf-/i36) .—These notes relate to the biolo,gy of L. concavus, commonly 

 known as the rhubarb curculio. 



Dock (Rumex crispus) appears to be the favorite food plant of the larvre. 

 Sunflower and thistle were examined by the author for egg punctures with 

 negative results, and in one instance only were eggs found in a species of 

 Polygonum or smartweed. 



Oviposition is said to commence soon after emergence, eggs having been col- 

 lected in the field on June 1 ; it may continue until July 20, although the 

 greater number of eggs are deposited before the middle of June. In the labora- 

 tory eggs hatched in from 7 to 9 days. From 8 to 9 weeks are required for 

 the larvae to reach maturity. In the field the majority were pupating from the 

 second to the fourth week in August. Many adults emergetl during the first 

 week in September, practically all by September 11. The pupal period as 

 determined in the laboratory varied from 10 to 12 days. The adults ap- 

 parently go into winter quarters soon after emergence. 



It is said that if R. crispus is cut off several inches from the ground between 

 the middle and end of July and rain occurs soon afterwards, a large per- 

 centage of the larvae will die owing to the decay which sets la, since practically 

 all are in the roots at that time. 



