Circular No. 80. 



United States Department of Agriculture, 



BUREAU OF ENTOMOLOGY, 



L. O. HOWARD, Entomologist and Chief of Bureau. 



THE MELON APHIS. 



( Aphis gossy2)li Glov. ) 



By F. H. Chittenden, 



Entomologist in Charge of Breeding Experiments. 



NATURE OF ATTACK. 



The melon aphis, or, as it is commonly known, the ''melon louse," 

 injures plants hy piercing them with its beak and sapping their vital- 

 it3^ It occurs from early spring to late in autumn on melons and 

 other cucurbits of all kinds, and on many other crop plants, and in 

 seasons which favor its increase, notabl}" in summers following springs 

 that are cool and rain}^, it frequently develops in enormous numbers 

 and does verj^ serious damage, collecting in masses on the under sur- 

 face of the leaves of plants and causing them to curl, shrivel, and lose 

 color, and interfering with the ultimate development of the fruit. 

 Often it kills plants outright, and destroys whole fields or greatly 

 reduces the 34eld of fruit. An affected cantaloupe plant is illustrated 

 b}^ figure 1. 



The melon aphis, like others of its kind, excretes ''honey dew," but 

 this is not so copious as in the case of many species of aphides, for 

 example, certain forms which affect trees. When, however, the aphis 

 under discussion becomes unusually abundant, the honey dew covers 

 the leaves of the affected plants with a thin, sticky coating on which 

 the white cast skins of the aphides adhere, and this attracts attention 

 to injury, as does also the wilting and dying down of the plants. 

 Some persons notice this honey dew, and are unaware of the presence 

 of the insects. They speak of the injury as "hone}^ dew," and have 

 even applied this name to the insect itself." 



Quite too frequently, b}^ the time the presence of the melon aphis 

 in injurious numbers is noticed, irreparable damage has been accom- 

 plished and the insects have for the most part migrated to other 

 pastures. 



« Attack by many forms of aphides, especially those which excrete honey dew 

 more copiously, can be readily detected hy the presence of insects which feed on the 

 sweet excretion. Among these are flies, wasps, bees, and especially ants. The 

 melon aphis, however, is not an especial favorite with ants, altho some common spe- 

 cies are occasionally found in attendance upon it. The pavement ant ( Tetramorium 

 cxspitiun L. ) is the only species which has thus far been observed by the writer, and 

 neither ant nor aphis appears to be in any way dependent on the other for its exist- 

 ence, contrary to that which is the case with many other aphides, particularly those; 

 which have root-feeding forms. 



10248— No. 80—06 



