364 EXPERIMENT STATION RECORD. [Vol.43 



eient parasite has been discovered in tliis cnuiiti'v, a (•lial<,'id()id of tlie genus 

 IMeurdtropis, apparently nndescrihed. 



Oidy suggestions can be made as to cimtrol measures, l)ut they will doubth'ss 

 be similar to those applicable against C. cinctua and C. p!jgm<rus. If, as now 

 seems probable, this insect confines itself in this country to the small grain 

 crops as host plants, crop rotation will prove au effective means of reducing 

 damage from it. 



An annotated list of 56 references to the literature cited Is appended. 



The clover and alfalfa seed chalcis-fly, T. D. Urbahns {U. S. Dept. Afir. 

 Bui. 812 iJ!)20), pp. 20, pis. 8, fifj-s. 2).— This pest, described by Howard in 18S0 

 as Eunjtoiiia fioichris and for some years supposed to be a parasite of the 

 clover flower nii<lge, has been for many years a pest of clover and alfalfa seed 

 in the Middle and Western States, as described in a popular account previously- 

 noted (E. S. K., 32, p. 454). At the present time it is known to be present in 

 practically every locality in the United States wliere either red clover or 

 alfalfa seed is grown to any extent, and has been found in seed from Europe, 

 Asia, and South Africa. 



The habit of this species of feeding within the growing seeds of alfalfa and 

 red chjver is quite different from the general habits common to most of the 

 other members of this group, many of which are parasitic in the lai'val stage 

 upon various forms of insect life. Its injury consists entirely of the hollowing 

 out of the developing seeds, the injury having been completed by the time the 

 alfalfa seed pods and the clover heads have matured. The loss caused by it is 

 to the growing of alfalfa or clover for a seed crop, it interfering in no way 

 with the growing of either for forage purposes. The plants seeds of which are 

 attacked are alfalfa, red clover, bur clover (MecJicago hispida vars.), M. 

 faJcatn, M. riitheiiiia, HI. tunefana, ilA. tuhcrculota, and M. orubica. The other 

 common clovers, namely, white, alsike, yellow sweet, white sweet, and sour 

 clover, apparently are not attacked. The loss caused frequently varies from 

 50 to 400 lbs. of seed per acre as a result of the destructive work of the pest, 

 and there is frequently an additional loss caused by the planting of uncleaned 

 seed and a loss of time and money in replanting. 



The first adults appear in the spring, 4 or 5 weeks after warm weather has 

 set in, the egg being usually placed just beneath the inner integument of the 

 seed, sometimes between the cotyledons, and frequently within the semi- 

 li(iuid contents of a cotyledon. At Pasadena, Cal., the period of incubation 

 varied from 7 'to 12 days in April; about 5 days were required in June. 

 The larva never leaves the seed in which it is developing, and where two or 

 more larvfe chance to be in the same seed, one or both itsually perish before 

 development is completed. Molts apparently occur indefinitely in the larval 

 stage.^ Under the most favorable conditions, the larvre complete development ii 

 12 days, while in early spring tlie period was prolonged to 30 days. Aestivatio) 

 occurs frequently in the larvie during the months of Jul.v, August, and Sep 

 teml)er. Favorable conditions may at any time cause transformation to the 

 pupal stage, or aestivation may continue into hibernation. The transforma- 

 tion usually occurs at any time between March and July of the following 

 season, though in exceptional cases the larval stage may be continued into the 

 second year. The period of pupation in early spring requires an average of 

 about 30 days, while the pupal period in midsummer is from <5 to 10 days. 

 While some of the lai'\'?e apparently go into hibernation as early as August, 

 adults may be seen emerging from the infested seeds and seed pods in October 

 and Novembex'. 



The author's observations show that in southwestern Arizona this species 

 may have as many as 4 genei'ations in a single season. The minimum number 



I 



