396 INSKCTUIUES, FUNGICIDES, AND WKKD KILLEPxS. 



anil proiluces jilinrtiou of the tubers. Very 

 energetic niethoils are adopted to prevent 

 it being imported into France [and Great 

 BritainJ. It showeil itself in Europe as far 

 back as 1877, but the sources of infection 

 have been destroyed each time that it has 

 been observed. 



Lethrus cephalotes (big-headed leth- 

 rus).— The letlirus is a sort of bmisii-r (cow- 

 dung insei-t '.) wliich is injurious to vines. 

 It is 2 centinictrcs long, its l)Oily is globular 

 and black. Tlir l.thni-; i^ chietly met with 

 in Russia and Au-.tn,i-l luugary. It is noc- 

 turnal, and digs its hinruw near the stocks. 

 Before dawn it issues from its hiding-place 

 to ascend the vines and cut the young vine 

 shoots at tiieir base, and carry these into its 

 burrows. 



Leocania unipunctata. — The caterpillars 

 of this tortrix penetrate inside grass stems 

 and thus greatly injure meadows. 



Lophodermium pinastri (pine leaf cast). 

 —Fall of the leaves of the pine. This para- 

 site commits great depredations, especially 

 in nurseries of two to three years old. As 

 early as the autumn of the first year the 

 seedlings are invaded and tlie leaves are 

 spotted with brown and become red. Sper mo- 

 gonia are formed ; as these grow the leaves 

 wither ii)) c(iiiipl('t('ly. The black perithecEe, 

 larger rrr('|rt:i 'lis t1i,ni tin' spermogouia, are 

 not fiiriii-J until iIm' Im] lowing year on the 

 same si]it>. Alter piMlmiged wet weather 

 the pyrothecte open through a slit and show 

 the asci filled with a bundle of spores. 

 These spores spread the disease. Special 

 weather conditions— a mild winter and a wet 

 summer— gi-eatly favour the growth of this 

 parasite. It may then devastate a nursery. 

 The young plants attacked by the rouge 

 may be regarded as lost, but if part of their 

 leaves remain intact they may rehabilitate 

 themselves A plant attacked by the rouge 

 is too weak to be transplanted. 



LoPHYRUs PINI (pine saw-fly).— 1 centi- 

 metre long ; lic-id bl.u'k, <-nrselet yellow with 

 black spots, alMoiiirii ydldw. The females 

 lay their eggs iiisi,lr tin- pine needles; the 

 green larvte guiiw Uic needles ami weave 

 against the leaves small cocoons of brownish 

 silk. Tile second generation appears in July, 

 tlie third in Octoljer. This generation nym- 

 phoses and lays its eggs in the moss at the 

 foot of the tree. 



LOPOS SULCATDS. Grisette de la Vir/ne. — 

 This bug of 7 millimetres with yellow bands 

 and points, appears at end of May and at- 

 tacks the flower buds of the vine, sinking 

 its sucker intn tlic-m. The female lays its 

 eggs in the cra'ks of t lir Imrk and the crevices 

 of the vine pr.ijis, iH-.tciHlily in the medulla 

 of the cut vine shoots. The larv?e hatch in 

 the following spring and spread first on 

 grass and on mustard, and then on the vine. 



LUCANDS CERVUS (st;i'4-l tlr). — Large 



coleoptera, 3-t rcntiinrl nvs Imul', furnished 

 with very higlily develoi„.,l ,leei--liorn-shapcd 

 mandibles. The larv;c, the development of 

 wliich takes four to five years, bore holes in 

 the trunks of the oak, birch, and beech. 



LvuA CAMPESTRLs (pine saw-fly).— Black 

 and yellow fly, 2 centimetres long, yellow 

 wings, appears in June, and does the same 

 damage to pines as the L. prtilensis does to 

 meadow plants. The larva Iniries itself in 

 the moss at the foot of the stem in the 

 month ot August, there to pass the winter. 



Lyua ERYTHROCEPHALA.— The hirva at- 

 tacks pine needles and hides itself at the toot 

 of the tree in June. 



Lyua i>ratensis (meadow saw-fly).— Yel- 

 low and black fly, 1-3 millimetres in length. 

 It flies in May. The larvae, 2 centimetres, 

 are brown with a yellow head. They gnaw 

 the leaves and descend in the month of August 

 into the soil to pass the winter in a sort of 

 lodge. 



Lygus I'Ratexsis (meadow bug). — This 

 bug is sometimes very injurious to apple-tree 

 and pear-tree buds. 



Merulios lac'RY.mans (dry rot).— This 

 fungus, allied to the Polypora, is not a para- 

 site of the wood of our trees but is the most 

 dreadful destroyer of building timber. In 

 Europe it is widespread and does great 

 damage. It chiefly attacks reshious woods 

 and produces the dry rot of pine tunber and 

 pitch-pine. It sometimes also attacks the 

 oak ; its development is favoured by mois- 

 ture. When the presence of this parasite is 

 reported in a town it is iieeiss;ivy to take 

 great precaution to avoid .iuitaiiiiiiation of 

 construction timber. If one spore is laid on 

 the surface of one of these timbers it will 

 suffice to contaminate tiie whole house. 



Mildew, see Erysiphes. 



Mole Cricket, see Gryllotalpa vul- 

 garis. 



Monilia frutigexa (brown rot of stone 

 fruits). — This funu'us r;iiis ■■< urcat ravages, 

 especially in Amen i. m p.-a-h nurseries. 

 The disease is charu. ten/.ed l.v the browning 

 of the fruit, the flesh ol whuh shrivels up, 

 becomes as hard as horn, mummities, and 

 finally only forms a harcl layer round the 

 stone. The mycelium which lives in the in- 

 terior of the pulp fructifies the same or the 

 following year. Perennial during winter in 

 the withered fruit, it revives in the spring 

 under tlie influence of the heat, and produces 

 grey tufts consisting of wreaths of spores 

 which spread the disease. In Europe it is 

 especially a wouud parasite. Fruits, whether 

 stone or pip fruits, may be invaded by it, 

 especially if wounded. 



Mulberry Diskask, Bacterian. — Boyer 

 and Ltimlier .lisi oveicd that this disease is 

 due to the /; irt.Tiinii Mori. It shows itself 

 on the outsiile by lirown-black spots on the 

 lower face of the leaves and the liranches ; 

 on the latter the spots are elongated and 

 are eroded in the form of more or less deep 

 cankers. The disease begins on the top of 

 the branches, which appear carbonized over 

 a c'crtaiii Iciigtli and l>ent in the form of a 

 cross. TIic leaves soon wither, rolling up 

 towanls the midrib. 



Nectria cinnabauina (necrosis of wood ; 

 coral spot disease).— This fungus, which 

 generally lives as a saprophyte on dead 



