12 



The species dealt with in this bulletin include the meadow frog- 

 hopper, Philaenus spumarius, which has a wide range of food-plants, 

 comprising buttercup, yarrow, thistle, Helianthus, orange dock, daisy, 

 clover, primrose, choke-cherry and plum, as well as several cultivated 

 crops. The heads of the plants attacked wither and fail to produce 

 seed. P. lineatus is a grass-feeding froghopper, preferring timothy- 

 grass and redtop for its food-plants. The eggs of this species are 

 e\Hdentlv laid in the autumn, probably in the stems of their food- 

 plants ; ' the larvae hatch about mid- June, the frothy masses, which 

 are a characteristic feature of these froghoppers, affording good 

 protection to the nymphs during their development. From mid-July 

 only adults are found, but oviposition is apparently delayed until 

 about the end of August. Frequent rotation from grass to some 

 other crop is advocated as a means of keeping the froghoppers in 

 check, while ploughing should be done in spring or late autumn. As 

 it is almost certain that eggs occur in the grass-stems during autumn, 

 winter and early spring, burning the surface dead grass \\all destroy 

 the eggs of these and many other species. The use of a hopperdozer 

 immediately after the hay is gathered would trap recently-developed 

 adults. Early mowing would probably reduce the numbers consider- 

 ably, and, where the insects are abundant, the gain in later growth 

 would probably compensate for the loss of quantity in the crop. 



Lepyronia quadrangular is, Say (angulated froghopper), which greatly 

 resembles the meadow species, is neither abundant nor of economic 

 importance in Maine. Bush and tree froghoppers include Aphrophora 

 parallela.. Say, which is found abundantly on Scotch pine twigs ; 

 Chstoptera obtusa, Say, occurring on alder and a variety of plants and 

 shrubs, including white birch and hazel ; C. j^roteus, Fitch, found on a 

 variety of plants, especially dogwood. C. xanthocephala, Germ., 

 has been found in the nymphal stage on chrysanthemums, though the 

 original food-plant may have been ragweed. Philaronia hilineata-, 

 Say, is rarely found in Maine, but occurs abundantly on the vegetation 

 of the plains in Dakota and Montana. 



Hinds (W. E.). Carbon Dfsulphid as an Insecticide.— C/. S. Dept. Agric, 

 Washington, D.G., Farmers' Bull. no. 799, June 1917, 21 pp. 

 [Received 7th November 1917.] 



Chemically pure carbon bisulphide is a clear, volatile liquid with a 

 sweetish odour resembling that of ether or chloroform ; it does not 

 injure or stain fabrics or food materials. The commercial variety, 

 however, which has a yellowish colour and unpleasant odour, due to 

 contained sulphuretted hydrogen, should not be poured directly upon 

 food-stuffs, although its vapour will not injure them. 



As an insecticide it may be used against three classes of insects : — 

 those that live underground on the roots of plants or that nest in the 

 ground as do some Aphids, white grubs [Lachnosterna], mole-crickets, 

 ants and others ; species that attack stored products, such as grain 

 msects, pea and bean weevils, various domestic pests and mill insects ; 

 and species that can not be controlled by the methods commonly 

 employed for their near relatives, such as' various wood-borers that 

 can not be reached mth poisons, but can be easily killed with 

 vapours. 



