102 



THE GAKDENER'S ASSISTANT. 



soot, and lime before planting. As soon as the 

 Cabbages are cut, dig up the stems and burn 

 them before the grubs have time to gnaw their 

 way out of the galls. Trench the ground deeply 

 to bury pupae, and give a good dressing of gas- 

 lime over the toj) spit when turned down. 



Carrot Fly (Psila Rosce). — The perfect insect 

 is a two-winged fly with a shining black body 

 tinted with green, and furnished with a long, 

 pointed ovipositor behind. The head is globular 

 and rusty yellow, while the wings are yellowish, 



4fiMHi> 



Carrot Fly (Psila Rosre). 



1. Larva ; 2, magnified. 3 and 4. Larvae appearing from the galleries exca- 

 vated in the Carrot. 5. Form of pupa ; 6, magnified. 7 and 8. The Fly 

 (natural size and magnified). 



with ochreous veins. The small maggots are 

 cylindrical, legless, pointed at the head, blunt 

 at the tail, pale shining ochreous and trans- 

 parent, with a black head. The rusty-yellow 

 pupa lays up in the soil, and in summer hatches 

 out in the course of three or four weeks. There 

 are several broods, and maggots may be found 

 in Carrots left in the ground even in winter. 



Remedies. — Good cultivation, by enabling the 

 young plants to make a free and rapid growth 

 from the earliest stages onwards, will often 

 secure a good crop, even in places where the 

 fly may have been troublesome in former times. 

 The ground should be trenched 2 feet deep in 

 winter to bury pupae which may be in the soil, 

 and allow the roots of the Carrots to penetrate 

 freely and perpendicularly. What manure is 

 given should be placed 15 inches or 18 inches 

 below the surface, and a good dressing of gas- 

 lime should be spread over the top spit after it 

 has been turned into the bottom of the trench. 

 Good crops of Carrots have been taken from rich 

 sandy, and also from peaty soils. In garden 

 cultures, where the soil is of a heavy, clayey 

 nature, great success has accrued by taking out 

 the natural soil to a depth of 2 feet and filling 

 in with peat or leaf mould, sandy loam, or sand, 

 and old potting-bench soil thoroughly mixed. 

 Early Carrots may be sown thinly, and receive 

 no thinning till fit for use, as the loosening of 

 the soil favours insect attack. Main crop, or late 



Carrots, on the contrary, should be thinned as 

 soon as they have made a few rough leaves. 

 Good results have been obtained by dressing the 

 ground after the seed is sown with a mixture 

 of wood ashes and petroleum, at the rate of 

 a quart of the latter to a cwt. of the former, 

 and repeating the dressing when the plants 

 are a few inches high. Sand might be em- 

 ployed instead of wood ashes, the object being 

 the even distribution of the petroleum. For 

 this reason kerosene emulsion or petroleum 

 emulsion, because cheaper, might be used to 

 water the plants after thinning them. The 

 emulsion is made by boiling J lb. of soap in a 

 gallon of water, and pouring in this state into 

 2 gallons of either of the oils mentioned, and 

 churning the mixture with a syringe or force- 

 pump for five minutes; to each gallon of the 

 emulsion, which readily mixes, add 20 gallons 

 of water, and when cold run it along the lines 

 of Carrots, avoiding the foliage as much as 

 possible, The emulsion in either case penetrates 

 the soil better than the ordinary article. At 

 the time of sowing, good results have followed 

 from dressings of a gallon of spirits of tar to a 

 barrowful of sand, as in the case of petroleum 

 and wood ashes, also dressings of salt, pigeons' 

 and fowls' dung, quicklime, gas-lime, and soot. 

 All of these should be pointed into the soil 

 before sowing; besides being insecticides, most 

 of them are also fertilizers. Liquid manure and 

 ammoniacal liquor serve the same purpose, and 

 should be applied after the operation of thinning. 

 Good exhibition Carrots may be obtained by 

 making holes 18 inches deep with a dibbler in 

 previously well-prepared soil, and then filling 

 the holes with a compost of sandy loam, wood 

 ashes, pigeons' dung, and sand well mixed to- 

 gether; on the top of this sow a few seeds to 

 be thinned to one when the seedlings grow. 



Cattleya Fly (Isosoma mxhidearum or /. 

 CatfJei/ce). — This insect belongs to the family of 

 ichneumons, which usually prey upon other 

 insects. It has a black body, hairy shoulders, 

 and four very transparent wings. The female 

 lays her eggs upon the young roots, buds that 

 should develop into pseudo-bulbs, on the flower- 

 stems and flower-buds, and the maggots, when 

 hatched out, penetrate these parts of Cattleyas, 

 causing gouty swellings. The maggots are 

 cylindrical, legless, strongly segmented, and 

 white. As the fly breeds summer and winter 

 in Orchid houses, there are several broods, and 

 one to three of the maggots may be found in 

 each cavity of the swellings. The grubs of a 

 small midge are sometimes found in company 



