THE AMERICAN ENTOMOLOGIST. 



99 



these live are too various to enumerate, 

 and only two species are especially men- 

 tioned ; — C. nigra, which attacks young 

 pears, and C. tritici, often very destruc- 

 tive to wheat. But in the wheat fields, at 

 this time, there are no more than a few 

 pairs of partridges, quails and larks, and 

 the insects in question are, at any rate, 

 almost invisible from their small size and 

 their delicacy of form. The same may be 

 said of other minute flies, which cause de- 

 formities in the young wheat stalks, — such 

 as species of Oscinis and Chlorops. 



Most of the horse and cattle-flies, in- 

 cluding the bot-flies, etc., are protected 

 from birds by their extreme agility. 



Cherries, olives and oranges are attacked 

 by flies, of which a few are probably taken 

 by birds, but the larvae can only be reached 

 by eating the fruit they infest. 



In short, it may be said of the Diptcra 

 in general that but a very small part of 

 them are no.xious, and that birds find an 

 abundance of inoffensive flies for food, and 

 do us little service. 



The Lepidoptera embracing a much larger 

 number of enemies, those most harmful are 

 reviewed in some detail, to show to what 

 extent they are exposed to birds. 



Only the Pierida need be mentioned 

 among diurnals. The services of a pair of 

 chafiinches in cleaning a garden of cabbage 

 caterpillars {Pieris brassicce and P. napi), 

 have been greatly vaunted, but with evident 

 exaggeration. Chaffinches and other small 

 birds avoid caterpillars as hairy as those of 

 the Pieridce. The larvae of Leucania 

 cratcBgi, injurious to fruit trees, live en- 

 tirely exposed to the birds in summer, and 

 in winter remain suspended in groups to 

 the bare branches in purse-like structures 

 made of leaves ; but the birds respect them 

 altogether. The caterpillars are too hairy. 



The nocturnal Lepidoptera comprise 

 many more exceedingly noxious species. 

 Hepialus htimuli devours the roots of the 

 hop, Sesia mutilUeformis lives beneath the 

 bark of the pear trees, and Aglaope infausta 

 {Zygcenidce) eats the leaves of the almond. 

 Clisiocampa neustria, a very hairy cater- 

 pillar, living in societies, defoliates the 



apple and pear and often prevents their 

 ripening fruit. 



The processionary caterpillar of the pine 

 (Cnethocampa pityocampa), which often de- 

 stroys the foliage of an entire forest, and 

 continues its ravages year after year, is in- 

 closed during the winter in a tough nest, 

 firmly attached to the leaves, and is also 

 thickly covered with stinging hairs; Liparis 

 chrysorrliKa, very injurious to fruit trees, 

 is likewise hairy, and sheltered by a silky 

 screen in winter. It is against this noxious 

 and very common species that the laws 

 requiring the destruction of caterpillars 

 are chiefly directed. Cossus ligniperda de- 

 vours the liber at the base of the trunk of 

 willows, chestnuts and elms, often killing 

 the trees by girdling them. Zeuzera 

 aesculi mines beneath the bark and ex- 

 cavates the trunks and branches of pear 

 and apple trees. Triphmna pronuba eats 

 lettuce and other garden plants at night, 

 but hides in the earth by day. Nearly all 

 the garden Lcgumi/wscc, the cereals, maize, 

 tobacco and beets, fall a victim to the 

 common cut-worm or green worm; Ag- 

 rotis segettiin, and Agrotis exclamationis 

 are equally destructive. Hadena brassicte 

 devours the leaves of cabbage and even 

 penetrates to the center of the head. Hel- 

 iothis armigera and Leucania zem eat the 

 kernels of young corn beneath the husk, 

 and the former also attacks the kidney 

 bean in the pod. The Pyralid, Aenophthira 

 pilleriana, is so destructive to the grape as 

 to have attracted the attention of the gov- 

 ernment, and Cochylis roserana is almost 

 equally dangerous. The apple Pyralid, 

 Carpocapsa pomonana, is the moth which 

 makes pears and apples wormy, and causes 

 often a general dropping of the unripe 

 fruit. Others of the same genus similarly 

 effect plums, chestnuts, acorns and olives. 

 Colonies of the caterpillar, Ypoiwmeuta 

 malinella, protected by a common web, 

 gradually cover whole branches of the 

 apple, completely denuding them of leaves 

 flowers and fruit. Finally the grain moths. 

 Tinea granclla and Butalis ccreaklla do 

 great injury to the garnered grain. 



Now what relief from this host of enemies 



