106 INDIRECT INJUKIES CAUSED BY INSECTS. 



admired of all table vegetables, concerning which gardeners are most apt 

 to pride themselves, and bestow much pains to produce in perfection, I 

 mean the cauliflower, is often attacked by a fly, which, ovipositing in that 

 part of the stalk covered by the earth, the maggots, when hatched, occasion 

 the plant to wither and die, or to produce a worthless head. 1 Even when 

 the head is good and handsome, if not carefully examined previous to 

 being cooked, it is often rendered disgusting by earwigs that have crept 

 into it, or the green caterpillar of Pontia Rapes. In 1836, as we learn from 

 Mr. West wood, great injury was done in the market gardens to the west 

 of London to the cauliflowers and other plants of the cabbage tribe by a 

 species of aphis covered with a purple powder, which had not been before 

 observed by the gardeners, who called it a new kind of blight. 2 



Our peas, beans, carrots, parsnips, turnips, and potatoes are attacked in 

 the garden by the same enemies that injure them in the fields 3 ; I shall 

 therefore dismiss them without further notice, and point out those which 

 infest another of our most esteemed kinds of pulse, kidney beans. These 

 are principally Aphides, which in dry seasons are extremely injurious to 

 them. The fluid which they secrete, falling upon the leaves, causes them 



sufficiently indicated the injurious effect of this interruption of the proper office of 

 the sap. What was particularly remarkable, considering the locomotive powers of 

 these insects, was that the young turnips, sown in August after the wheat and rye, 

 close to acres of Brussels sprouts (which all round Brussels are planted in the open 

 fields among other crops), infested by myriads of these insects, were not more eaten 

 by them than they usually are in England, and produced good average crops. It 

 would seem, agreeably to a fact which I shall mention in its place in speaking of the 

 food of insects, that they prefer the taste of leaves to -which they have been accus- 

 tomed, to younger plants of the same natural family ; and hence perhaps the previous 

 sowing of a crop of cabbage-plants in the corner of a field meant for turnips, might 

 allure and keep there the great bulk of these insects present in the vicinity, until the 

 turnips were out of danger. 



1 Perhaps this fly is the same which Linne confounded with Tachina Larvarum, 

 which he says he had found in the roots of the cabbage (Syst. Nat. 992. 78.). I say 

 " confounded," because it is not likely that the same species should be parasitic in 

 an insect, and also inhabit a vegetable. It is obviously the same described by Kollar 

 from Bouche' under the name of Anthomyia Brassicce (159.), which he states often 

 destroys whole fields of cabbages by boring into the roots and stalks. 



2 Trans, Ent. Soc. Land. ii. proc. xxi. 



3 On examining some young garden peas and beans about four inches high, I 

 observed the margins of the leaves to be gnawed into deep scollops by a little wee- 

 vil (Sitona lineata}, of which I found from two to eight on each pea "and bean, and 

 many in the act of eating. Not only were the larger leaves of every plant thus 

 eroded, but in many cases the terminal young shoots and leaves were apparently 

 irreparably injured. I have often noticed this and another of the short-snouted Cur- 

 culios (S. tibialis) in great abundance in pea and bean fields, but was not aware till 

 now that either of them was injurious to these plants. Probably both are so, but 

 whether the crop is materially affected by them must be left to further inquiry. 

 Garden beans still more than the field kinds, Mr. Curtis informs us, greatly suffered 

 in 1841, from the holes which humble bees (Sombus terrestris and lucorum) made in 

 the blossoms (as they usually do) to get out the honey contained in the nectary, 

 which operation injuring the pods in their earliest state, four-fifths of them were 

 destroyed, and produced no beans. (Curtis in Gardener's Chron. 1841, p. 485.) 

 When at Shrewsbury in August 1839, 1 found almost every pod of the garden peas 

 brought to market inhabited by a single yellowish-white lepidopterous larva, three 

 or four lines long, which had eaten more or less of each pea, but which, though 

 several assumed the pupa state and entered the earth in the box in which they were 

 placed, never became perfect moths. 



