355 



therefore beneficial. Other injurious species which have become 

 estabhshed are whiteflies on azaleas from Belgium, ants from Holland 

 and France, Pseudococcus sp. on palms and bay trees from Belgium, 

 Tingitids on rhododendrons from Holland, and Orgyia (Notolophus) 

 antiqua also from Holland. 



Davis (J. J.). Cages and Methods of studying underground Insects. — 

 Jl. Econ.Entom., Concord, viii, no. 1, February 1915, pp. 135-139, 

 12 figs. 



Tne best methods of breeding underground insects were determined 

 from a study of the life-history of Lachnosterna and related forms. 

 Coleopterous larvae with a three-year life-cycle were bred in several 

 different kinds of cages, descriptions and figures of which are given. 

 The most satisfactory and cheapest of these were ordinary red flower 

 pots, 12, 15 and IG inches respectively hi diameter and depth. Large 

 rectangular cages 5 by 8 feet and 2| feet below ground and 21- feet 

 above, constructed of metal and wooden frames covered with 18- 

 mesh pearl wire cloth, were useful as checks on the smaller cages. 

 Usually several species of the same genus were placed in each of the 

 large cages. The pots were filled with soil which had been sifted to 

 remove bisects, and sown with a mixture of timothy and blae grass. 

 Pieces of old maize stalks were included, since young grubs of Lach- 

 nosterna, Cyclocephaln, etc., feed on decaying vegetation, and for larvae 

 which were partially or wholly scavengers, manure was added. Pots 

 thus prepared were buried almost to the top in the soil and covered 

 with cylinder-shaped tops. Beetles, preferably pairs collected in 

 copula, were introduced, foliage, if necessary, being supplied. Fresh 

 seed and water had to be given as required. During winter the covers 

 were replaced by straw, or straw and manure, to a depth of one foot ; 

 this was advisable as the larvae could not go do\Mi to tlieir normal 

 depth for hibernation. The above cages were examined once or twice 

 a year to obtain specimens of different ages. For obtamhig eggs 

 and records of individual pairs, standard size pots with finely sifted 

 soil were used ; they were covered with wire screen tops within which 

 single pairs were placed. The soil was not so^^^l nor were the pots 

 sunk in the ground, but foliage was supplied and a record kept of the 

 amount eaten by the beetles. The cages were sifted every few days, 

 using a 16-mesh sieve ; if the soil were sufficiently moist, small balls 

 of earth containing the eggs remained intact. The eggs were then 

 placed in boxes of soil, moistened when necessary, and kept in a cool 

 place comparable with natural conditions. To study the habits, 

 growth, moults, etc. of the larvae, one-ounce tin ointment boxes were 

 used ; a grain or two of wheat was added to these. Older larvae 

 were fed on grains of maize and examined once a week. For con- 

 venience, 60 or 70 tin boxes were fitted mto a tray. When the hiber- 

 nation period approached, all grain was removed and the soil moistened; 

 the tins were then either left m the trays or placed in boxes and buried 

 to a depth of one to two feet. 



Tiie moults, length of instars, etc. of the army worm, Cirphis {Helio- 

 phila) unipuncta, were successfully ascertained ; in this case control 

 experiments were made to determine whether or not the tin boxes 

 produced unnatural conditions for the larvae. A. A. Girault. from 



(C172) b2 



