322 



PSYCHE. 



[February i8gg 



elsewhere (Psyche, viii, 164), the great 

 majority of species pass the winter in 

 the egg stage, hatch in the spring, and 

 attain maturity in summer or early fall, 

 being, in consequence, most numerous 

 in the adult stage in August and Sep- 

 tember. This is the case with all of the 

 Tryxalinae and Acridiinae and most of 

 the Oedipodinae. Of the latter, how- 

 ever, tliree species {Arphia sulphiirea, 

 Chortophaga viridifasciata, Hippls- 

 c/is iuberculatus) liatch in midsummer, 

 pass the winter as nymphs, and reach 

 maturity in April or May, flying until 

 midsummer or rarely until September ; 

 these are all hardy species and reach a 

 high latitude. The Tettiginae form a 

 marked exception to the other groups 

 in passing the winter as adults, being 

 most numerous in September, October, 

 April and May, and rare in midsummer ; 

 most of these, also, extend throughout 

 the district. Immediately on the coast 

 development is delayed from three to 

 ten days in spring and the season is 

 considerably prolonged in the fall. 



The study of distribution would be 

 greatly aided by the publication of local 

 lists giving exact locality and date of 

 capture, with such biological notes in 

 reference to environment as careful 

 and continued observation will secure. 

 Very much might be done by local col- 

 lectors in this way and it is to be hoped 

 that more attention will be paid this 

 group than heretofore. The most 

 effective method of adding to our know- 

 ledge of the subject would be by making 

 a series of transections of the isotherms 

 3t the proper season over portions of 



the district to be investigated. By this 

 means an experienced collector could 

 secure a large amount of valuable data 

 with a minimum of eftbrt. 



Some of the problems that should be 

 borne in mind in connection with 

 future observations are : the extent to 

 which distribution, either local or 

 general, is influenced by other factors 

 than climate or temperature, such as 

 food-plants, the necessity of a particular 

 kind of soil or other substance for 

 oviposition or as nidus for the eggs 

 (rotten wood, pithy stems, etc.) ; the 

 relative abundance locally of winged 

 and wingless species; the relative 

 abundance and width of range from 

 year to year of each species, to deter- 

 mine whether it tends to increase or 

 decrease in numbers and extent of 

 habitat, to supplant others or be sup- 

 planted, — particularly, in New Eng- 

 land, to determine whether M. sciiddcri 

 and D. viridis are or not extending 

 their range, etc. 



To sum up : — Locust distribution is 

 primarily and very distinctly climatal 

 in character, habitats varying specific- 

 ally in range but closely paralleling 

 the isotherms. In its details it is influ- 

 enced to a very high degree by 

 physiography and its attendant condi- 

 tions, such as character of the soil, 

 humidity, etc. In its broader features 

 it is eminently characteristic of life 

 zones and regions, agreeing well with 

 those drawn from study of the verte- 

 brates.* It is in many cases dependent 



* This is noticeable in even a cursory glance at tl e 

 cosmopolitan distribution of the family. 



