ARBORICULTURE 



9 



these birds, and in a well prepared report of his 

 observations upon a farm, he says : "The tree- 

 sparrows, fox-sparrows, white-throats, song- 

 sparrows and j uncos fairly swarmed during 

 December in the briers of ditches between the 

 corn field. They came into the open fields to 

 feed upon weed seed, and worked hardest where 

 the smart-weed formed a tangle on low ground. 

 Later in the season the place was carefully ex- 

 amined. In one corn field near a ditch the 

 smartweed formed a thicket over three feet 

 high, and the ground beneath was literally black 

 with seeds. Exaimnation showed that these 

 seeds had been cracked open and the meat re- 

 moved. In a rectangular space of eighteen 

 square inches were found eleven hundred and 

 thirty half seeds and only two whole seeds. 

 Even as late as May i,?th the birds were still 

 feeding on the seeds of these and other weeds 

 in the fields ; in fact, out of a collection of six- 

 teen sparrows, twelve, mainly song, chipping 

 and field sparrows, had been eating old weed 

 seed. A search was made for various weeds 

 but so thoroughly had the work been done that 

 only half a dozen seeds could be found. The 

 birds had taken practically all the seed that was 

 not covered; in fact, the song-sparrow and sev 

 eral others had scratched up much buried seed." 

 He made an examination of some four thou- 

 sand stomachs of sparrows of many sorts, col- 

 lected all over the United States, and in his 

 report of this work he says that "during the 

 colder half of the year the food of these birds 

 consists almost entirely of the seeds of weeds." 

 Professor Beal has estimated that during the 

 two hundred days in winter in which the tree- 

 sparrows remain in the State of Iowa, reckon- 

 ing ten sparrows to the square mile and one- 

 fourth of an ounce as the daily ration, eight 

 hundred and seventy-five tons of weed seed are 

 eaten by this species alone in that State. In 

 addition to their great usefulness as seed-de- 

 stroyers, the family Fringillidae do much good 

 in destroying injurious insects. Weed and 

 Dearborn, in their summary of the economic 

 value of the birds, say: "The most striking 

 particulars brought out by a study of their diet 

 are the enormous amounts of weed seed taken 

 during winter, and the extent to which these 

 so-called seed-eaters take insect food in spring 

 and summer, especially in the presence of an 

 unusual abundance of an edible species. For 

 example, in an orchard infested by canker- 

 worms, forty-seven members of this family had 



eaten 91 per cent, of insects and only 7 per cent, 

 of seeds, canker-worms alone making 40 per 

 cent, of the food." 



The rapidity with which the insect pests in- 

 crease and the destructive powers with which 

 they are possessed is marvelous. Reaumer, in 

 his history of the insects, estimates that one 

 aphis may be the progenitor of not less than 

 5.904,900,000 during the few weeks of her exist- 

 ence. Theodore Wood, in his book on "Our 

 Insect Enemies," says : "It may seem a widely 

 and extravagant and unjustifiable statement if 

 we say that but for certain opposing agencies, 

 the aphis would overrun the entire world ; that 

 it would leave scarcely a green leaf upon the 

 earth, and that it would cause such terrible 

 devastation that all terrestial life would wholly 

 disappear, and the globe become one vast desert, 

 incapable of supporting animation, and utterly 

 without living beings of any kind. Still more 

 impossible* would it appear were we to state 

 that this ruin and devastation would be the out- 

 come, not of many centuries of gradual increase, 

 but of only a few short months. Incredible as 

 the assertion may seem, however, such results 

 are no more than must logically follow if the 

 aphis should be allowed to remain perfectly 

 unmolested during the period of but a single 

 year." And this is only one of these destruc- 

 tive insect pests with which we must contend. 



Indeed, there are pestiverous and destructive 

 insect pests for every condition, place and plant 

 about us. For instance, in the air, by day, we 

 have flies, butterflies, wasps, moths and winged 

 ants, and at night moths, mosquitoes, bugs and 

 beetles. Upon our shrubs and small fruits 

 we have slugs, leaf hoppers, flea beetles, rose 

 chafers, climbing cutworms and caterpillars. In 

 our gardens we have cutworms, cabbage-worms, 

 root maggots, cucumber, pea and bean weevils 

 and squash bugs. In our orchards we have 

 borers, coddling moths, bark lice, plant lice, 

 cankerworms and leaf caterpillars. In our 

 meadows we have grasshoppers, cutworms, 

 army worms, crane flies, white grubs and root 

 borers. In our corn and wheat fields we have 

 wire worms, ball worms,, root worms, Hessian 

 flies, ants and chinch bugs. In our forests we 

 have plant lice, bark lice, trunk borers and leaf 

 caterpillars. In our marshes, ponds and streams 

 we have water beetles, water bugs, mosquitoes 

 and May flies. 



Prof. C. R. Marlatte Assistant Entimologist, 

 in charge of the experimental field work of the 



