INSECT POOD. 27 



Peas. — Next to the beans was a patch of peas so ravaged by the pea 

 plant-louse that the crop was a total loss. Only one of the 20 birds 

 had eaten it — a chipping sparrow. It was somewhat surprising to find 

 even one, for the various species of plant-lice are seldom utilized by 

 birds for food, but later it was learned that the chipping sparrow had 

 elsewhere been found preying on the pea plant-louse. This insect has 

 only recently become known to science. It suddenly made its appear- 

 ance along the Atlantic coast and occasioned a loss of $3,000,000 in 

 the first season." 



Melons. — Melons at times suffered badly from insects. In lot 4, not 

 far from the woods, a patch of watermelons in the critical stage of 

 growth, when the first leaf had appeared between the thick, nutritious 

 cotyledons, was ravaged by three species of leaf -beetles — Diairotiea 

 l$-pu7ictata, D. vittata, and Systena elongata. There were from six 

 to a dozen beetles on each plant, and they ate so many of the cotyle- 

 dons that practically the whole piece had to be replanted. When they 

 were most abundant the patch was watched for several hours on June 

 15, 1899, and again on June 16, but no birds came to its aid. Birds 

 are known to eat these three insects at times, but the remoteness of 

 the melon field from water courses, hedgerows, and other cover 

 attractive to the most abundant species may explain their failure to do 

 so in this case. At the same date (June 15, 1899) Diahrotica vittata 

 was found on canteloupes in blossom on the Hungerford farm, but 

 although there were from 12 to 20 insects on each plant, they appeared 

 to be doing little harm. The patch was observed for an hour in the 

 late afternoon, and three field sparrows, the only birds near it, were 

 collected, but none of these insects were found in their stomachs. 



Tobacco. — During the last of August and first of September, 1899, 

 tobacco was grown on the Bryan farm in lot 2 near the negro cabin 

 (Pl.Vin, fig. 1), and also on the other two farms. The entire crop was 



Fig. 6.— Tobacco-worm (after Howard; loaned by Division of Entomology). 



damaged by worms (fig. 6) to the extent of 50 percent of its value, 

 in spite of the fact that men, women, and children turned out to pick 

 worms every day for two weeks. "W hen the pests were most abund- 

 ant (August 28-31) an effort was made to learn whether birds were 

 joining in the war against them. Field sparrows and chipping spar- 

 rows spent considerable time hopping among the plants, a song sparrow 



« Circular 43 (2(1. series), Div. Entomology, Dept. Agr., p. 3, 1901.' 



