Sept. 1894.] 



INJURIOUS IXSECTS AXD FUNGI. 



53 



They suck the juices from the leaves, hindering the growth of 

 the plants, while their peculiar excretion known as " honeydew," 

 falls on the upper surface of the leaves, and chokes their pores. 



The most common of these two species is Aphis hrassicce. 

 The winged female which brings forth living young is black as 

 to the head and thorax, with a gTeen or yellowish green 

 abdomen, and dark yellow legs. The wingless females, kno\\Ta 

 commonly as lice, are oval in shape, of a greenish colour Avith 

 green antemise, and are covered -w ith mealy coats. 



The other species is Ai>/((.< /■.'/'.'. The wingless female is 

 greenish, and, in some cases, oclireou.s yellow. The -sAnnged female 

 has a black head and thorax with yellow abdomen, yellowish 

 legs and dark antennae. This species is found upon a great 

 number of plants besides those of the Brassica group. 



In ordinary farm practice it is almost impossible for these 

 aphides to be harboured in egg or larval form during the winter 

 upon the crops they had injured in the summer, as these are 

 either fed oft* by . sheep or are topped and tailed, the tops 

 being ploughed in at once. Cabbage plants put in during- the 

 autumn are of course excepted. It is quite possible that the 

 aphides may pass the winter on these and on other plants of 

 the cabbage tribe intended for seed. But without doubt the 

 main attack of these aphides has come from weeds which have 

 retained the eggs during the winter, have hai-boured wingless 

 females near their stems and roots, and have furnished them 

 with food in the earliest spring, and nourished them until the 

 cultivated plants were ready for them. Charlock is a most 

 dangerous source of attack from these aphides as it shelters them 

 and furnishes early food for them, and charlock has been most 

 abundant this year. Other cruciferous weeds also harbour them. 



Washing, or syringing, infested plants with soft soap and 

 quassia, in the proportion of 7 lbs. of soft soap and the extract of 

 7 lbs. of quassia chips, to 100 gallons of water, is a good remedy 

 if it can be carried out. This may be put on by means of knap- 

 sack machines, or by garden engines set upon high wheels and 

 furnished with long lengths of hose, or by a horse distributor 

 which can be set so as to spray the under surface of the leaves. 



Lady birds, Goccinellce, clear oft" quantities of these aphides, 

 and there are several species of flies which do good service. 

 One is known as Trionyx ra'pca, a very small hymenopterous 

 insect, which puts an egg into the body of the aphis, and its 

 product, a tiny maggot, feeds upon its vitals and destroys it. 



, WiREWORMS. 



There was an unusual attack of wireworms in the spring- 

 throughout the country. Persons travelling by rail noticed 

 bare patches in many wheat-fields, while young oats showed 

 unmistakable signs of wireworms at their roots. Fortunately 



