ECONOMIC ZOOLOGY^ENTOMOLOGY. 855 



The pear psylla, P. J. Parrott and H. E. Hodgkiss (Neio York State Sta. 

 Circ. 20. pp. 8. fits. 2, fi<gs. 7). — A brief description of this insect with directions 

 for its control. 



The cotton or melon aphis, C. E. Sanborn {Oklahoma Sta. Bvl. 98, pp. S-20, 

 flgs, jf), — The first part of this bulletin consists of a general description of this 

 aphid, its life history, and injury. This is followed by a somewhat deUiiled 

 account of investigations made of its predatory enemies, including lady beetles, 

 a chrysopid, syrphus fly, etc. 



Hippoihimla convergent was found to deposit 556 eggs during the 34 days from 

 April IT to May 21. One of the larvre, which hatched April 17, consumed a 

 total of 396 aphids in the 11 days following. During its development it molted 

 April 19, 21. 23, and 28, after which it pupated, this stage lasting 4 days, a total 

 of 17 days being required for development from egg to adult lady beetle. The 

 daily rate of reproduction of this lady beetle is about double that of the melon 

 aphis, while the total reproduction of a single lady beetle is about 8 times 

 greater than that of a single melon aphis. 



Coccinella tnunda deposited 448 eggs during the 36 days following June 25, 

 and a larva of this species consumed 553 aphids during the 9 days following 

 June 26. The egg stage lasted 2 days, the lanal period 9, and the pupal period 

 3 days. 



A larva of C. notata consumed 181 aphids during the 12 days following its 

 hatching on April 14. Four days were passed in its egg stage, 14 in its larval, 

 and 4 days in its pupal stage. 



C. sanguinea was found to deposit 251 eggs in the 24 days following July 2. 

 Mcgilla maculata consumed 595 aphids in the 11 days following July 19. This 

 species deposited 219 eggs in the 24 days following August 6. In August. 2 

 individual larvse of this species consumed 265 and 322 aphids. respectively, in 

 the 9 and 10 days following August 16. The amount of food consumed daily was 

 found to decrease as cool weather approached. Another individual deposited 

 156 eggs in the 47 days following September 7. 



Two adults of Srymnus locwii consumed a total of 487 aphids in the 5 days 

 following their emergence on June 20, and 50 eggs were deposited by an indi- 

 vidual during the 9 days following April 25. A larva of this species, which 

 hatched from an egg on April 29, consumed 56 aphids in the following 14 days. 

 Five days were passed in the egg stage, 14 in the larval, and 13 in the pupal 

 stage. Two other common coccinellids, S. tcrminatus and Exohomus coiistriatus, 

 were found to develop in a similar period and their aphid capacity to be about 

 the same as /S. loewii. 



The lace-wing fly Plorahnnda ocniata was found to deposit 66 eggs in 7 days 

 following April 16. Three hundred and eighteen aphids were consumed by a 

 larva of this species in the 12 days following hatching on April 23. The egg 

 stage required 7 days, larval stage 12 days, and pupal stage 13 days. 



HemeroUus gossypii deposited 125 eggs in the 28 days following June 7. 

 Thirty-four aphids were consumed by the immature form in the 10 days follow- 

 ing March 14. The egg stage required 2 days, larval stage 10 days, and pupal 

 stage 5 days. 



A larva of the syrphus fly Bacca clavata consumed 458 aphids in the 11 days 

 following July 19. Two days were passed in the egg stage, 11 in the larval 

 stage, and 5 in the pupal stage. 



The author states that the nicotin product " blackleaf 40," used at the rate 

 of 1 gal. to 900 gal. of water will control the melon louse. Applications of this 

 insecticide should be made as soon as the aphids begin to appear in the field in 



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