Onwards and upwards – aphid flight trends follow climate change

Abstract

Onwards and upwards -aphid flight trends follow climate changeTwo aphid species with contrasting life cycles and responses to climate change. On the right Utamphorophora humboldti, an invasive species from North America (Blackman & Eastop 2000), where it is host alternating, but in the United Kingdom is almost certainly anholocyclic (continuously parthenogenetic) on grasses. This species has shown the most dramatic advance in flight phenology and has shown the largest population increases. The maple aphid, Periphyllus testudinaceus, on the left, here pictured on horse chestnut, Aesculus hippocastanum, is a native non-host-alternating ant-attended species (Blackman & Eastop 1994) and has a contracting flight season.In Focus: Bell, J.R., Alderson, L., Izera, D., Kruger, T., Parker, S., Pickup, J., Shortall, C.R., Taylor The world faces an uncertain future; climate change and the concerns about the security of food production feature prominently on political and scientific agendas world-wide. In this issue, Bell et al. (2015), drawing on the unique 50-year data set amassed by the suction trap network run by the Rothamsted Insect Survey (RIS), elucidate the mechanisms advancing aphid phenology under climate change and show how by using biological traits we can make predictions about emerging crop pests. Here, I discuss their findings in the context of phenological coincidence and host plant availability.

Complex life histories predispose aphids to recent abundance declines

“…First, suction traps directly measure aphid flight activity, and only indirectly measure the abundance of aphids feeding on plants where ecological connections actually occur (Bell et al, 2015). Second, these datasets fail to represent species that do not produce winged forms or that fly below the height of suction traps, and will underestimate aphid abundance when conditions are not conducive to flight (Leather, 2015; Loxdale, 2018). Third, aphids collected at each sampling location include local aphids and those migrating over large distances (Schmidt et al, 2012; Sheppard et al, 2016), complicating efforts to link suction‐trap counts with local environmental variables.…”

Achtergronden bij een eventuele aanpassing van de teeltvoorschriften voor bewaring van suikerbieten en voederbieten

“…Het is al geruime tijd bekend dat sommige bladluissoorten, waaronder Myzus persicae, zonder geslachtelijke voortplanting en het leggen van een winterei de winter overleven (Walters, 1987). Door de steeds warmer wordende winters is het waarschijnlijk dat meer bladluizen (en bladluissoorten) een anholocyclische levenswijze volgen, waardoor er vroeger in het jaar kolonies aanwezig zijn van waaruit ook vroeger migratie zal plaatsvinden (Bell et al, 2015;Leather, 2015;Trebicki, 2020;Zhou et al, 1995). Er zullen dan ook eerder gevleugelde bladluizen in zulke kolonies aanwezig zijn en bij gunstige weersomstandigheden gaan vliegen.…”

Aspects, Including Pitfalls, of Temporal Sampling of Flying Insects, with Special Reference to Aphids

“…They also tend to involve different degrees of specialism [62], so that the sexual and pre-sexual winged migrant aphids returning in the autumn to the woody host (e.g., Rosaceae) tend to be much more specialist than the more polyphagous asexual winged forms migrating in the spring to the secondary host/s, although even these forms tend to be specialist within a particular group of related host plants, e.g., Poaceae or Fabaceae [24,25]. In aphids, the switching of hosts and indeed locating of plant hosts generally is related to plant host phenology [63,64] as well as distribution [65], whist the timing of the spring migration is governed by the preceding minimum January–February temperatures [43,44,63,66], and the intensity and duration of the autumn migration back to the woody overwintering host in host alternating (heteroecious) species by both weather-related and nutritional factors [43,63,66,67,68]. Crowding is also a well-known trigger causing the development of winged individuals within colonies on the secondary host [26,58,67,68,69].…”