343 



observations described in this paper were carried out in Missouri, where 

 the insect appears to be gradually becoming more abundant. Malus 

 sylvestris at a mature stage is chiefly attacked, though nursery stock 

 may sometimes be injured. Periods of abundance appear to alternate 

 with periods of scarcity 0. geminatella is a leaf-mining form. Larvae 

 hatching from eggs deposited on the lower leaf surface at once enter 

 the tissue, where they remain for about two weeks and form a charac- 

 teristic tentiform type of mine. Pupation occurs in a cocoon formed 

 on the upper surface or at the tip of the leaf. The pupal period varies 

 from a few days to a week in midsummer. Hibernation takes place in 

 the pupal stage in a cocoon protected by a folded edge of a leaf. Adults 

 appear in May and the life-cycle is completed in four or five weeks ; 

 a new brood occurs each month until November. The food-plants 

 include the apple, crab-apple, Crataegus spp. (hawthorn), plum, cherry, 

 pear and wild cherry. 



0. geminatella does not become abundant until late summer and 

 autumn, when the trees have matured ; control measures are thus 

 only necessary when the numbers are excessive and likely to be 

 injurious during the next season. In large orchards the best method 

 is to turn under fallen leaves bearing cocoons by means of a disk used 

 in shallow cultivation in early spring. In small areas, the leaves may 

 be raked together and destroyed by burning or covered with soil or 

 stable manure. The insect is controlled to a considerable degree by 

 parasites, of which the following Chalcidoids have been identified : — 

 Sympiesis nigrifemora, Ashm., S. tischerae, Ashm., S. meteor i, Gir., 

 S. dolicJiogaster, Ashm., and Eulophus lineaticoxa, Gir. 



Cory (E. N.). Notes on Insect Control. — Maryland Expt. Sta., College 

 Park, n.d., 4 pp. [Received 8th June 1916.] 



Lead arsenate can be obtained commercially in either the acid or 

 basic form. The acid compound when combined with lime-sulphur 

 reduces the lime content of the latter and causes the precipitation of 

 free sulphur. It has, however, more rapid insecticidal powers than 

 the basic salt. It is thus recommended for use by growers of truck 

 crops, wathout admixture with lime-sulphur. The basic sajt with 

 lime-sulphur should be used by fruit-growers. Sodium sulphides 

 should not be used in combination with lead arsenate as a foliage spray ; 

 barium sulphides on the other hand may be safely combined. Tobacco 

 extract should be used against Aphids on orchard trees, melons and 

 peas. In orchards the spray should be used at the rate of f U.S. pt. 

 Black Leaf 40 to 100 U.S. gals, water, to which 5 lb. soap has been 

 added. Against pea aphis [Acyrthosiphon pisi] and melon aphis [Aphis 

 gossypii], the spray should consist of 10 ozs. Black Leaf 40, 50 U.S. 

 gals, water and 4 lb. fish oil soap. Against the rose beetle, the follow- 

 ing spray is recommended :--4 lb. lead arsenate, 100 U.S. gals. 

 Bordeaux mixture and 1 U.S. gal. molasses. 



Jarvis (E.). Combating the Cane Beetle. — Queensland Agric. J'., 

 Brisbane, v, no. 5, May 1916, pp. 280-281. 



Experiments conducted to observe the effect of certain chemicals 

 on the larvae of the cane beetle [Lepidiota] yielded the following results : 

 (1) Creolin (1 pt. to 50 gals, water) destroyed 100 per cent, of the larvae 



