Dala Research Station, Malaita, British Solomon Islands Protectorate.
Study of two forms of the adult Stenocranus minutus
Article first published online: 24 APR 2009
1975 The Royal Entomological Society
Transactions of the Royal Entomological Society of London
Volume 127, Issue 3, pages 241–254, December 1975
How to Cite
MAY, Y. Y. (1975), Study of two forms of the adult Stenocranus minutus. Transactions of the Royal Entomological Society of London, 127: 241–254. doi: 10.1111/j.1365-2311.1975.tb00573.x
- Issue published online: 24 APR 2009
- Article first published online: 24 APR 2009
- 4th March, 1975
- 1In studies on Stenocranus minutus, two winged forms of adults have been observed, macropterous and sub-macropterous. Macropterous individuals, with extra-long wings, have not been previously observed or described. Probably only the macropterous form disperses by flight.
- 2The two forms differ in their wing lengths, intensity and extent of pigmentation.
- 3The rate of maturation differs in the two forms. In macropters, maturation is delayed; the period of oviposition is shorter and they are less fecund.
- 4Macropters do not live as long as sub-macropters.
- 5The macropters weigh less than the sub-macropters.
- 6Under laboratory conditions, both forms can hop but the macropterous forms fly for a longer time than the sub-macropters.
- 7At 25°C, more macropterous forms were produced on wilting Dactylis than on green, succulent Dactylis.
- 8Dispersal of field population was inferred from changes in proportions of the two forms and by simultaneous occurrence of macropters in aerial suction traps.
- 9The macropterous forms of S.minutus migrate a few weeks after emergence while still immature and migration coincides with drying up of host plant, Dactylis glomerata L.
- 10Relatively high temperature, low wind speeds and a small number of hours of sunlight seem to favour dispersal by flight in S.minutus.