ECONOMIC ZOOLOGY ENTOMOLOGY. 857 



Ser. B, No. 8. p. 148). — An account of this pest, which is well known in Argen- 

 tina, its life history, and the disease which it causes in sheep. 



The serpentine leaf miner, F. M. Webster and T. H. Paeks ( U. S. Dept. Agr. 

 Jour. Agr. Research. 1 (1913), No. 1, pp. 59-88, pi. 1. figs. i7).— The serpentine 

 \eaf miner {Agromyza pusilla), a dipteran generally distributed over the United 

 States and having a wide range of food plants, is a source of injury to foliage 

 through the burrowing of the larvje between the membranes of the leaf and 

 devouring the parenchyma. 



"The injury takes the form of a serpentine 'mine' which encircles the leaf, 

 gradually widening as the larva increases in size. Leaves of white clover and 

 frequently of young alfalfa often have the entire cellular tissue devoured, 

 leaving only the 2 membranes. There is usually only 1 larva present in each 

 leaf. The injury from this insect is greatest in the Southwest, where the dis- 

 colored leaves, which in severe cases become brown, are sometimes present in 

 sufBcient numbers to lower the quality and grade of the hay. The injured 

 leaves can be foimd in the fields from May until November, the larviB continuing 

 to feed until killed by frosts. In Florida the larv?e continue feeding through- 

 out the winter. 



" The insect hibernates in the puparia beneath the surface of the soil at the 

 base of the plants. There are 5 or 6 generations in latitude 41°, the number 

 varying with the length of the growing season. The generations overlap to 

 such an extent that all stages can be found in the fields during most of the sea- 

 son. During the period of highest temperature in summer the larvae are found 

 usually infesting plants protected from the direct rays of the sun. During this 

 period in the arid Southwest the insect almost completely disappears from the 

 fields, reappearing in September. The eggs are deposited in the leaf tissue and 

 inserted in punctures identical with those made by the adult in feeding. The 

 egg stage during June is 4 days. The larvie feed continuously day and night 

 and confine their work to a single leaf. The larval period during June is 4 

 days. In the Eastern States pupation occurs entirely in the soil. It takes place 

 commonly in the larval chambers in the leaf in the arid Western States. The 

 pupal period during June is 10 days. The average period of the complete life 

 cycle is 23 days. 



" Besides alfalfa the following field crops are subject to attack : Clover, cow- 

 peas, rape, and cotton. A few nearly related and very similar leaf miners are 

 known to attack timothy, wheat, oats, and grasses. When these crops are 

 affected, the mine usually extends the entire width of the leaf, and may kill 

 the plant if it is very young." 



Some 28 hymenopterous parasites, of which Dianli7ius begini is the most im- 

 portant, attack and consume the larva? and pupje within their mines. These 

 are highly efficient and serve to keep the insect in control. The efficiency of the 

 parasites decreased upon the approach of cool weather. Many of these para- 

 sites are functional in the control of more than one species of leaf miner, and 

 are very widely distributed. Frequent cutting of alfalfa kills the larvae in the 

 leaves and does much to protect this crop. This method should be followed 

 where the injury becomes serious. Deep fall or winter plowing is advocated for 

 annual forage crops and cei'eals in order to bury deeply the hibernating puparia 

 located near the surface of the ground." 



A bibliography of 10 titles is appended. 



A serious pest of CofEea arabica in Belgian Kongo, R. Matn£; (Bui. Agr. 

 Congo Beige, 3 {1912), No. 4, pp. 911-917, figs. 5; abs. in Rev. Appl. Ent., 1 

 (1913), Ser. A, No. 1, pp. 22-24; Internat. Inst. Agr. [Ro^ne], Mo. Bui. Agr. 

 Intel, and Plant Diseases, 4 {1913), No. S, pp. 492, 493). — A longicorn beetle 



