319 



to the systematic classification of genera only, is a fitting introduction 

 to a further undertaking, which it is hoped may shortly be attempted, 

 of dealing in a similar manner with the 10,000 odd species of Coleoptera 

 that comprise this fauna. 



With the object of making the determination of any of the insects 

 as simple as possible, the volumes are supplied with many useful 

 keys as well as excellent plates and text figures. 



Abbey (G.). Cyaniding Vines when in Giowth.— Gdnr s' . Chron.. 

 London, Ixxi, no. 1841, 8th April 1922, p. 170. 



As the application of cyanide to vines in the dormant stage failed 

 to exterminate mealy-bugs [Pseudococms], an application of 2ioz. 

 was tried when the buds had made more than a quarter of an mch 

 of growth, some shoots being an inch long. Only a few of the shoots 

 that were unusually advanced were damaged, and all the mealy-bugs 

 were destroyed. About 2,000 other plants were in pots in the vinery, 

 comprising some 35 varieties in all stages of growth and flower. Young 

 tomatos in seedhng pots with their second leaves were nearly all 

 killed. The tips of the young growths of Chrysanthenimn and 

 Pelargonium were damaged, but the mature leaves and blossoms 

 did not suffer. Better results may be obtained with cyanide applied 

 just as the leaves begin to fall and the bunches are all gathered than 

 when the vines are quite dormant. 



Smee (C). British Ladybird Beetles. Their Control of Aphids.— 



Fruit Grower, Fruiterer, Florist & Mkt. Gdnr., London, liii, 

 nos. 1376, 1377 & 1378, 13th, 20th & 27th April, 1922 pp 

 675-676, 717-718, & 759-760, 5 figs. 



The study of the life-histories and food habits of the Coccinellids 

 here described has been undertaken to find out to what extent the 

 controlling power of the beetles is limited by the discrepancies existing 

 between their range of activity and that of their prey. The species 

 dealt with are Adalia bipundata, L., Coccinella septempunctata, L., 

 C. decempundata , L., var. variabilis. 111., and C. undecimpundata. L. 

 A description is given of all stages of these beetles, with particulars 

 of their distribution. 



Pairing and oviposition continue alternately over an indefinite 

 period, oviposition taking place every second day. The eggs are laid 

 m batches and hatch in 5-9 days. The larvae remain on the egg-mass 

 for at least twenty-four hours, sometimes two days. It is not certain 

 what they feed on, but they will injure unhatched eggs, causing them 

 to dry and shrivel up ; they will attack large Aphids. but are only 

 capable of controUing the small ones. The first moult occurs three 

 to five days after hatching, the .second three to seven days after the 

 first, the third four or five days later. The time between the third 

 and fourth moult is usually .seven to nine days, of which only a portion 

 is spent in active feeding. The adult emerges in 9-12 days, but 

 towards the end of the year the pupal stage may be considerably 

 lengthened. The total life-cycle is four to seven weeks. The earliest 

 eggs are laid by the overwintering adults about the middle of April. 

 Adults of this generation emerge a month later, and the second genera- 

 tion covers the period from the middle of May to the middle of June. 

 The beetles arising from this generation produce offspring that become 

 adults at the end of July, and these again give rise to a fourth brood 

 from which adults emerge in October. 



