The winter development, reproduction and lifespan of viviparae of Sitobion avenae (F.) (Hemiptera: Aphididae) on wheat in England

Abstract

Viviparae of Sitobion avenae (F.) in clip-cages on winter wheat in field plots in southern England were monitored throughout the 1980-81 winter to determine characteristics of development, reproduction and lifespan under winter conditions. Rate-temperature relationships for development and reproduction were well described by straight lines when temperatures were measured above 3°C. A simple thermal-time scale could therefore be used for both processes. The parental morph and the time of year modified thermal-time requirements for the production of an adult's first 20 nymphs but did not affect those for development. For both alatae and apterae, nymph production per day-degree was greater than at higher temperatures and the relationship between reproductive rate and age was different. The minimum temperature experienced by the aphids was -7°C; survival was good, with little low temperature mortality. Total fecundity of apterae was usually greater than at higher temperatures, though some apterae and alatae that were deposited in October had low fecundity, possibly because they were insufficiently acclimatized at the onset of cold winter weather. Overwintering alatae had lower development rates, reproductive rates and total fecundity than apterae and did not survive as long, but were restless as young adults and appeared ready to migrate. Oviparae were produced from late September to mid-October but not after this, suggesting that the clone used could 'switch off' sexual morph production in winter.

The cost of being able to fly in the milkweed-oleander aphid,Aphis nerii (Homoptera: Aphididae)

“…Our failure to find a fecundity difference between morphs contrasts with numerous other studies (MacKay and Wellington, 1975;Taylor, 1975;Cannon, 1984;Hutchison and Hogg, 1984;Watt, 1984;Shu-sheng and Hughes, 1987;Williams and Wratten, 1987;other refs in Roll, 1986). The effect of wing morph in this study is due to a pooling of differences between morphs that were produced by the same mother and reared on the same host plant at the same density.…”

“…Delayed reproductive maturation by winged individuals appears to be a general rule in wing dimorphic aphids (Campbell and Mackauer, 1975;MacKay and Wellington, 1975;Cannon 1984;Hutchison and Hogg, 1984;Carroll and Hoyt, 1986;Dixon and Howard, 1986;Shu-sheng and Hughes, 1987;Williams and Wratten, 1987) and in other species of Homoptera (Denno, 1985), although this effect can be due to slower development to the adult stage or to delays in onset of reproduction following adult eclosion. The delay is sufficiently long to reduce fitness for winged aphids, as measured by the F' statistic which incorporates timing of reproduction in the life history.…”

The overwintering of cereal aphids on Gramineae in southern England, 1977–1980

“…S. avenae overwintered anholocyclically on most of the available Gramineae, even during the severe 1978/1979 winter. Although some may overwinter holocyclically in some areas (Dewar & Carter, 1984) and sexual morphs and fertile eggs were produced in the laboratory and in field cages (Hand, 1983;Hand & Wratten, 1985;Williams & Wratten, 1987), holocycly appeared to be rare, as recorded elsewhere in Europe (e.g. Dedryver, 1978).…”

Overwintering of the sycamore aphid, Drepanosiphum platanoidis

“…Anholocyclic species are dependent on parthenogenetic females surviving the winter (Leather, 1992). In some cases, aphids employ mixed strategies, depending on genotype, climate or location (Blackman, 1972;Williams & Wratten, 1987). This is useful in areas where winters are sometimes mild since the presence of parthenogens gives the aphid population a head start in spring (Leather, 1993).…”