Size‐mediated priority and temperature effects on intra‐cohort competition and cannibalism in a damselfly

Abstract

1.A shift in the relative arrival of offspring, for example a shift in hatching time, can affect competition at the intraspecific level through size-mediated priority effects, where the larger individuals gain more resources. These priority effects are likely to be affected by climate warming and the rate of intraspecific predation, that is cannibalism.2. In a laboratory experiment, we examined size-mediated priority effects in larvae of the univoltine damselfly, Lestes sponsa, at two different temperatures (21 and 23°C). We created three size groups of larvae by manipulating hatching time: early hatched with a large size (extra-advanced), intermediate hatched with an intermediate size (advanced) and late hatched with a small size (non-advanced). Thereafter, we reared the larvae from these groups in non-mixed and mixed groups of 12 larvae.3. We found strong priority and temperature effects. First, extra-advanced larvae most often had higher survival, growth and development rates than non-advanced larvae in mixed groups, compared to groups that consisted of only extra-advanced larvae. Second, temperature increased growth and development rates and cannibalism.4. However, the strength of priority effects did not differ between the two experimental temperatures, because there was no statistical interaction between temperature and treatments. That is, the mixed and non-mixed groups of non-advanced, advanced and extra-advanced larvae showed the same relative change in life-history traits across the two temperatures. 5. Non-advanced and advanced larvae had similar or higher growth rate and mass in mixed groups compared to non-mixed groups, suggesting that predation from advanced larvae in the mixed group released resources for the non-advanced and advanced larvae that survived despite cannibalism risk. Thus, a thinning effect occurred due to cannibalism caused by priority effects.6. The results suggest that a shift in the relative arrival of offspring can cause temperature-dependent priority effects, mediated through cannibalism, growth and development, which may change the size distribution and abundance of emerging aquatic insects. | MATERIAL S AND ME THODS | Study speciesOur study species was the damselfly Lestes sponsa, a univoltine, that is one generation/year, damselfly that is native to Europe (Askew, K E Y W O R D S cannibalism, intraspecific competition, larval size, Lestes, life history, priority effects, temperature | 639 Journal of Animal Ecology SNIEGULA Et AL.

Optimal reproductive phenology under size‐dependent cannibalism

“…The colonization of habitats and arrival times of species or offspring in a seasonal environment is important in predator–prey interactions and in forming the structure of communities (Anderson, Rowland, & Semlitsch, 2017; De Meester, Vanoverbeke, Kilsdonk, & Urban, 2016; Rasmussen, Van Allen, & Rudolf, 2014; Salamolard, Butet, Leroux, & Bretagnolle, 2000; Shulman et al, 1983; Sniegula, Golab, & Johansson, 2019). For instance, a large difference in arrival times of nymphs of two dragonfly species causes the exclusion of a late arrival species (Rasmussen et al, 2014).…”

“…This is known as priority effects, which emphasize how the sequence of breeding or other phenologies determine interaction strength. Priority effects are often size‐mediated (Rasmussen et al, 2014; Sniegula et al, 2019), as organisms emerge small and grow larger while their role as predators and prey shifts (Nosaka, Katayama, & Kishida, 2015). An early start can be a large advantage both in competitive and in predator–prey interactions, but is traded against the match with key resources during ontogeny (Durant, Hjermann, Ottersen, & Stenseth, 2007).…”

Optimal reproductive phenology under size-dependent cannibalism

“…The colonization of habitats and arrival times of species in a seasonal environment is important in predator-prey interactions and in forming the structure of communities [5][6][7][8]. This is known as priority effects, which emphasize how the sequence of breeding or other phenologies determine interaction strength.…”

Effects of predator cues carry over from egg and larval stage to adult life-history traits in a damselfly

“…For commercial use, contact journalpermissions@press.uchicago.edu. other patterns might occur (Ball and Baker 1996, Laurila et al 1998, Benard 2004, Costanzo et al 2011, Sniegula et al 2019b. However, few studies have focused on how predation risk during the egg stage affects the later larval and adult stages and whether a switch from high predation risk to low predation risk over ontogeny can be compensated for in later ontogenetic stages.…”