501 



Paddock (F. B.). The Cotton or Melon Louse — Life History Studies. 

 — Texas Agric. ExjA. Sta., College Station, Bull 2o7. December 

 1919, 54 pp., 4 plates, 3 figs. [Received 24th September 1920.] 



The synonyms of Aphis gossypii, Glover (cotton or melon Aphid), 

 as now understood, include Ajjhis citri, AshnL, A. citnj.Hi. AshnL, 

 A. cucumeris, Forbes, and A. cooki, Essig. It is widely distributed over 

 the world, and common throughout the United States where any of 

 its food-plants are grown. In Texas it is a serious pest of cotton, 

 melons, cucumbers and similar plants. The confusion in the identity 

 of this species has arisen from the very numerous food-plants that 

 have been attributed to it, but not all of these have been proved to be 

 food-plants by migration tests. 



In Texas, the normal form of rfeproduction is asexual throughout 

 the entire year. The alternative food-plants in that State have not 

 been determined. Fifty- one generations completed their life-cycle 

 in a period of exactly twelve months. The average reproduction 

 period was 21 "4 days, and the average number of young produced 

 was 84 "4. The migration tests indicated that the Aphids do not 

 migrate from cotton to plants of the melon family or the reverse. 

 Ants were found associated with the Aphids at all times, but no 

 definite relation was estabhshed. 



A. gossypii is reduced by natural enemies, being parasitised by Lysi- 

 pldebus testaceipes, Cress., and preyed upon by three species of Coc- 

 cinelhds — Megilla macidaf.a, deG., Hippodamia concergens, Guer., and 

 Coccinella munda, Say — and two species of Svrphid flies, SyrpJios 

 americanus, Wied, and AUograpta obliqua. Say. 



Paddock (F. B.) k Reixhard (H. J.). The Cowpea Wee\il. — Texas 

 Agric. Expt. Sta., College Station, Bull 256, December 1919. 

 92 pp., 6 plates, 3 figs. [Received 24th September 1920.] 



The commonest Bruchid infesting cowpeas in Texas is Bnichus 

 quadrimaculatus, F. All varieties of cowpeas grown in the State are 

 equally subject to attack, and the annual loss caused is very great. 



This Bruchid is very prolific, and under favourable conditions, 

 of which temperature is one of the most important, the life-cycle 

 may be completed in less than three weeks. In stored seed, breeding 

 is practically continuous throughout the year, and most of the insects 

 undoubtedly hibernate in such seed. About nine generations occur 

 in a year in Texas. 



The natural enemies of the immature stages are a predaceous mite, 

 a Chalcid {BrucJiobius laticeps, Ashm.) and an ego[-parasite {Uscana 

 semifumipennis, Gir.). It is not, however, sufficiently checked by 

 its natural enemies, and artificial remedial measures must be employed. 

 Proper harvesting (carried out just before the se^s are exposed by 

 the opening pod) wiU greatly reduce the initial infestation in the field, 

 while to prevent reinfestation, seed should be stored in tightly closed 

 containers. The insect can be destroyed in any stage by heating the 

 infested seed to a temperature of 146" F. for fifteen minutes, which 

 does not afiect the germination of the seed, or by fumigation with 

 carbon bisulphide at the rate of 4 lb. per thousand cu. ft. of space. 



