This README.txt was created by Keshi Zhang (University of Auckland) and was updated on 20 Dec 2025

GENERAL INFORMATION

1. Zhang K, Schausberger P, Zhang Z.-Q. 2026. Maternal age and density shape offspring foraging strategies in a predatory mite. Behavioural Ecology. In press.

2. Brief abstract

Maternal effects are key drivers of offspring phenotypic plasticity, influencing traits such as survival, growth, and behaviour. Maternal age at oviposition is an intrinsic factor governing such effects, which often exerts negative impacts on offspring traits. However, in the thelytokous predatory mite Amblyseius herbicolus, offspring of older mothers exhibit increased growth efficiency and reduced prey consumption. The proximate mechanisms of this inverse Lansing effect remain elusive, but this conservative offspring’ foraging strategy may reflect an anticipatory maternal response to mitigate intraspecific competition among later-produced offspring. Here, we investigated how maternal age at oviposition and maternal rearing density influence offspring foraging strategies. Eggs (i.e., offspring) were collected from mothers maintained under low- and high-density conditions and classified as Young or Old based on maternal age at oviposition. Offspring were then assessed for immature survival under low prey availability, prey consumption, predation incidence, latency to attack prey, and superfluous killing. Offspring of older mothers showed reduced prey consumption and lower predation incidence, whereas offspring of high-density mothers had higher survival under prey limitation. Maternal density partially modulated age-related effects. Our findings highlight the role of maternal effects in shaping adaptive foraging strategies and demonstrate that maternal influences can induce risk-averse behavioural changes in response to ecological conditions. Both intrinsic and extrinsic maternal factors shape offspring behavioural strategies, and maternal age, in particular, can serve as a dynamic source of variation influencing predator-prey interactions and population dynamics.

3. Originators

Keshi Zhang

4. Contact information

School of Biological Sciences, 3A Symonds Street, University of Auckland, Auckland 1010, New Zealand.

zhangk@landcareresearch.co.nz

5. Date of data collection

May–Aug 2025

6. Geographic location(s) of data collection

New Zealand


ACCESS INFORMATION

1. Licenses/restrictions placed on the data

CC-BY-NC 4.0 (Attribution-NonCommercial)


DATA FILES AND VARIABLES

[list each data file and the variables that it contains]

1. Egg size

The size of eggs affected by rearing density and age at oviposition.

 • id: subject ID
 • den: rearing density (Low or High)
 • age: age at oviposition (Young or Old)
 • length: egg length measured in micrometres
 • breadth: egg breadth measured in micrometres
 • v: egg volume measured in cubic micrometres
 • volume: egg volume in cubic millimetres.

2. Survival

Survival data from Experiment 1a.

 • id: subject ID
 • den: rearing density (Low or High)
 • age: age at oviposition (Young or Old)
 • sur: survival (Yes or No; 1 or 0)
 • ea: duration from egg to adult (day)

3. Consumption

Prey consumption data from Experiment 1b.

 • id: subject ID
 • den: rearing density (Low or High)
 • age: age at oviposition (Young or Old)
 • con: number of prey eggs consumed
 • ea: duration from egg to adult (day)

4. Predation

Predation data from Experiment 2.

 • id: subject ID
 • den: rearing density (Low or High)
 • age: age at oviposition (Young or Old)
 • latency: time taken from start to predation (min)
 • predation: predation outcome (Yes or No; 1 or 0)

5. Wasteful

Predation data from Experiment 3.

 • id: subject ID
 • den: rearing density (Low or High)
 • age: age at oviposition (Young or Old)
 • kill: number of dead prey
 • predation: number of fully consumed prey