DOI: 10.5061/dryad.pg4f4qs2h
title: Luring cannibal: dishonest sexual signalling in the springbok mantis

description: Sexual signals that attract the opposite sex are typically honest
 indicators of quality. However, sexually antagonistic selection can favour
 dishonest signals if poor quality members of the signalling sex can
 improve their own fitness at a cost to the opposite sex by conveying
 deceptive information in their signals. Here, using the sexually
 cannibalistic mantis Miomantis caffra, we found evidence that
 females in low body condition use sexual deception to exploit males as
 prey. Females of high condition produced 97% heavier oothecae than
 low-condition females, indicating that high-condition females were the
 optimal choice for males. However, in a simultaneous mate choice
 experiment using a T-maze olfactometer, males chose the pheromonal signals
 of low-condition females twice as often as those of high-condition
 females, indicating that female pheromonal attractiveness did not match
 female quality. In subsequent mating experiments, low-condition
 females attacked males 3 times more frequently and cannibalised them 4
 times more often than high-condition females did. Cannibalism provided
 significant material benefits for females of low condition, since oothecae
 produced by these females were 52% heavier when they cannibalised a male
 compared to when they did not. These results strongly suggest
 that low-quality females attract males dishonestly with their pheromones
 to boost fecundity through sexual cannibalism. Such deception could be
 widespread in sexually cannibalistic systems, especially if pheromone
 production is cheap, food limitation is common, and males represent a
 substantial meal for hungry females.
description: We conducted a series of laboratory experiments to investigate
 whether hungry (low-condition) females of the sexually cannibalistic
 springbok mantis, <em>Miomantis caffra</em>, deceive males
 with their pheromonal signals to reap the material benefits of
 cannibalising them. We used a T-maze olfactometer to test whether males
 preferred the pheromones of high- or low-condition females. We also
 performed mating trials to assess whether females of high or low condition
 were more or less aggressive and cannibalistic toward males. Finally, we
 collected measurements on the difference in fecundity between high- and
 low-condition females, as well as the effect of cannibalism on the
 fecundity of low-condition females.
description: # Luring cannibal: dishonest sexual signalling in the springbok mantis
 Dataset DOI: [10.5061/dryad.pg4f4qs2h](10.5061/dryad.pg4f4qs2h) ## General
 information ### Author information: A. Lead author contact information:
          Name:                        Laura Knapwerth          Email:
                        
 [l.knapwerth@t-online.de](mailto:l.knapwerth@t-online.de)         
 Institution:                Universität Hamburg                 B.
 Co-author contact information:          Name:                       
 Nathan W. Burke          Email:                       
  [nathwilliamb@runbox.com](mailto:nathwilliamb@runbox.com)         
 Institution:                Universität Hamburg ### Date of data
 collection: November 2022 to July 2024 ### Geographic location of data
 collection: Hamburg, Germany ## DATA & FILE OVERVIEW ###  1. File
 List: Data is contained in five files:    A. LC_-_mate_choice_trials.csv
 B. LC_-_control_choice_trials.csv C. LC_-_mating_trials.csv D.
 LC_-_fecundity_test_cann_vs_no_cann.csv E.
 LC_-_fecundity_test_low_vs_high.csv ## DATA-SPECIFIC INFORMATION FOR: ###
 A. LC_-_mate_choice_trials.csv #### 1. Number of variables: 30 #### 2.
 Number of cases/rows: 34 (one row per successful trial) #### 3. Variable
 List: A. 'trial.number' (categorical): Replicate-level
 identifier for mate choice trials (i.e., the numerical order in which
 trials were conducted) (34 levels: 1 to 34) B. 'trial.date'
 (date): The date that trials took place C. 'female.low.id'
 (categorical): Identifier for females of low condition (34 levels) D.
 'female.low.length' (numerical): The length of the prothorax of
 low-condition females at adulthood (in mm) E.
 'female.low.weight' (numerical): Weight of females of low
 condition (in g), measured at the start of mate choice trials F. 
 'female.low.condition' (numerical): Condition score of females
 of low condition, calculated as the residuals of the linear regression of
 the natural logarithm of 'female.low.weight' and the natural
 logarithm of 'female.low.length' G.
 'female.low.moult.date' (date): The date that low-condition
 females moulted to adulthood H. 'female.low.age' (integer): The
 age of low-condition females at the start of mate choice trials (i.e.,
 number of days from final moult to trial date) I.
 'female.high.id' (categorical): Identifier for females of high
 condition (34 levels) J. 'female.high.length' (numerical): The
 length of the prothorax of high-condition females at adulthood (in mm) K.
 'female.high.weight' (numerical): Weight of females of high
 condition (in g), measured at the start of mate choice trials L.
 'female.high.condition' (numerical): Condition score of females
 of high condition, calculated as the residuals of the linear regression of
 the natural logarithm of 'female.high.weight' and the natural
 logarithm of 'female.high.length' M.
 'female.high.moult.date' (date): The date that high-condition
 females moulted to adulthood N. 'female.high.age' (integer): The
 age of high-condition females at the start of mate choice trials (i.e.,
 number of days from final moult to trial date) O.
 'mean.female.length' (numerical): Mean prothorax length (in mm)
 of high- and low-condition female pairs used in each trial P.
 'female.length.diff' (numerical): The difference in length (in
 mm) between low- and high-condition female pairs used in each trial, as an
 absolute value Q. 'mean.female.age' (numerical): Mean age (in
 days) of low- and high-condition female pairs used in each trial R.
 'female.age.diff' (integer): The difference in age (in days)
 between low- and high-condition female pairs used in each trial S.
 'male.id' (categorical): Identifier for males (34 levels) T.
 'male.length' (numerical): The length of the male prothorax at
 adulthood (in mm) U. 'male.weight' (numerical): Male weight (in
 g), measured at the start of mate choice trials V.
 'male.condition' (numerical): Condition score of males,
 calculated as the residuals of the linear regression of the natural
 logarithm of 'male.weight' and the natural logarithm of
 'male.length' W. 'male.moult.date' (date): The date
 that males moulted to adulthood X. 'male.age' (integer): The age
 of males at the start of mate choice trials (i.e., number of days from
 final moult to trial date) Y. 'starting.time.hours' (integer):
 The time that trials started (in hours, in 24h time) Z.
 'trial.duration.secs' (integer): The amount of time (in secs)
 that males took to choose a female by entering one of the arms of the
 T-maze AA. 'choice.side' (categorical): The arm of the T-maze
 that males entered when choosing the pheromonal signal of a female (two
 levels: ‘left' and 'right') AB.
 'choice.condition' (categorical): The condition of the female
 that the male chose (two levels: 'low' and 'high') AC.
 'choice.value' (logical): Whether males chose females of low
 condition (scored as 1) versus high condition (scored as 0) AD.
 'trial' (categorical): Whether females were present for the
 trial (one level: 'females.present') ### B.
 LC_-_control_choice_trials.csv #### 1. Number of variables: 13 #### 2.
 Number of cases/rows: 20 (one row per successful trial) #### 3. Variable
 List: A. 'trial.number' (categorical): Replicate-level
 identifier for mate choice trials (i.e., the numerical order in which
 trials were conducted) (20 levels: 1 to 20) B. 'trial.date'
 (date): The date that trials took place C. 'male.id'
 (categorical): Identifier for males (20 levels) D. 'male.length'
 (numerical): The length of the male prothorax at adulthood (in mm) E.
 'male.weight' (numerical): Male weight (in g), measured at the
 start of mate choice trials F. 'male.condition' (numerical):
 Condition score of males, calculated as the residuals of the linear
 regression of the natural logarithm of 'male.weight' and the
 natural logarithm of 'male.length' G.
 'male.moult.date' (date): The date that males moulted to
 adulthood H. 'male.age' (integer): The age of males at the start
 of mate choice trials (i.e., number of days from final moult to trial
 date) I. 'starting.time.hours' (integer): The time that trials
 started (in hours, in 24h time) J. 'trial.duration.secs'
 (integer): The amount of time (in secs) that males took to enter one of
 the arms of the T-maze K. 'choice.side' (categorical): The arm
 of the T-maze that males entered (two levels: ‘left' and
 'right') L. 'choice.left' (logical): Whether males
 chose the left arm (scored as 1) or the right arm (scored as 0) M.
 'trial' (categorical): Whether females were present for the
 trial (one level: 'females.absent') ### C.
 LC_-_mating_trials.csv #### 1. Number of variables: 33 #### 2. Number of
 cases/rows: 63 (one row per male-female pairing) #### 3. Variable List: A.
 'trial.number' (categorical): Replicate-level identifier for
 mating trials (63 levels: 1 to 63) B. 'trial.date'
 (categorical): The date that trials started, i.e., the experimental block
 (3 levels: '2023-01-16', '2023-01-24',
 '2023-01-27') C. 'treatment' (categorical): The
 condition treatment that females belonged to (2 levels: 'low'
 and 'high') D. 'female.id' (categorical): Identifier
 for females (63 levels) E. 'female.length' (numerical): The
 length of the prothorax of females at adulthood (in mm) F.
 'female.weight' (numerical): Weight of females (in g), measured
 at the start of mate choice trials G. 'female.condition'
 (numerical): Condition score of females, calculated as the residuals of
 the linear regression of the natural logarithm of
 'female.weight' and the natural logarithm of
 'female.length' H. 'female.moult.date' (date): The
 date that females moulted to adulthood I. 'female.age'
 (integer): The age of females at the start of mating trials (i.e., number
 of days from final moult to trial date) J. 'male.id'
 (categorical): Identifier for males (63 levels) K. 'male.length'
 (numerical): The length of the male prothorax at adulthood (in mm) L.
 'male.weight' (numerical): Male weight (in g), measured at the
 start of mating trials M. 'male.condition' (numerical):
 Condition score of males, calculated as the residuals of the linear
 regression of the natural logarithm of 'male.weight' and the
 natural logarithm of 'male.length' N.
 'male.moult.date' (date): The date that males moulted to
 adulthood O. 'male.age' (integer): The age of males at the start
 of mating trials (i.e., number of days from final moult to trial date) P.
 'trial.duration.in.hours' (numerical): The amount of time (in
 hours) that males spent paired with females in mating trials Q.
 'trial.duration.in.secs' (numerical): The amount of time (in
 secs) that males spent paired with females in mating trials R.
 'female.attacks' (integer): The number of times females attacked
 males S. 'mating.binary' (logical): Whether mating took place
 (scored as 1) or not (scored as 0) T. 'cannibalism.binary'
 (logical): Whether cannibalism occurred (scored as 1) or not (scored as 0)
 U. 'time.from.m.to.c.hours' (numerical): For cases where
 cannibalism occurred after mating, the amount of time (in hours) that
 elapsed from the cessation of (the first) mating (i.e., when pairs visibly
 separated) to the onset of cannibalism (i.e., when females successfully
 grabbed hold of males and started eating them) V.
 'time.of.mating.hours' (numerical): The point of time in the
 trial (in hours) that the first mating ceased W.
 'time.of.cannibalism.hours' (numerical): The point of time in
 the trial (in hours) that cannibalism took place X.
 'mating.and.cannibalism' (logical): Whether both mating and
 cannibalism occurred (scored as 1) or only mating occurred (scored as 0)
 Y. 'attacks.before.mating.interaction.binary' (logical): For
 cases where mating occurred, whether the female attacked the male before
 the start of the interaction in which (the first) mating occurred (scored
 as 1) or not (scored as 0) Z.
 'attacks.during.mating.interaction.binary' (logical): For cases
 where mating occurred, whether the female attacked the male during the
 interaction in which (the first) mating occurred (scored as 1) or not
 (scored as 0) AA. 'attacks.after.mating.interaction.binary'
 (logical): For cases where mating occurred, whether the female attacked
 the male after the cessation of the interaction in which (the first)
 mating occurred (scored as 1) or not (scored as 0) AB.
 'number.of.interactions' (integer): The total number of
 male-female interactions during the mating trial, with an interaction
 defined as a discrete event/time period of physical contact between male
 and female that ends with physical separation of the pair AC.
 'mating.interaction.number' (integer): For cases where mating
 occurred, the chronological number of the interaction in which the first
 mating occurred AD. 'second.mating.interaction.number'
 (integer): For cases where mating occurred a second time, the
 chronological number of the interaction in which the second mating
 occurred AE. 'third.mating.interaction.number' (integer): For
 cases where mating occurred a third time, the chronological number of the
 interaction in which the third mating occurred AF.
 'cannibalism.interaction.number' (integer): For cases where
 cannibalism occurred, the chronological number of the interaction in which
 cannibalism occurred AG. 'first.mating.duration.hours'
 (numerical): The duration of the (first) mating in hours during which
 males copulated with females #### 4. Note: Variables Y, Z, AA, AB, AC, AD,
 AE, and AF were only used for supplementary calculations, plots, and
 analyses; variable AG was not used for any analyses ### D.
 LC_-_fecundity_test_cann_vs_no_cann.csv #### 1. Number of variables: 17
 #### 2. Number of cases/rows: 19 (one row per female) #### 3. Variable
 List: A. 'treatment' (categorical): The condition treatment that
 females belonged to (two levels: 'low' and 'high') B.
 'female.id' (categorical): Replicate-level identifier for
 females (19 levels) C. 'female.length' (numerical): The length
 of the female prothorax at adulthood (in mm) D. 'female.weight'
 (numerical): Female body weight at the start of the mating trial (in g) E.
 'female.condition' (numerical): Condition score of females,
 calculated as the residuals of the linear regression of the natural
 logarithm of 'female.weight' and the natural logarithm of
 'female.length' F. 'female.age' (integer): Female age
 (i.e., number of days from final moult to start of the mating trial) G.
 'male.id' (categorical): Replicate-level identifier for males
 (19 levels) H. 'male.length' (numerical): The length of the male
 prothorax at adulthood (in mm) I. 'male.weight' (numerical):
 Male body weight at the start of the mating trial (in g) J.
 'male.condition' (numerical): Condition score of males,
 calculated as the residuals of the linear regression of the natural
 logarithm of 'male.weight' and the natural logarithm of
 'male.length' K. 'male.age' (integer): Male age (i.e.,
 number of days from final moult to start of the mating trial) L.
 'mating' (logical): Whether females mated (scored as 1) or not
 (scored as 0) M. 'first.mating.duration.hours' (numerical): The
 duration of the (first) mating in hours during which males copulated with
 females N. 'cannibalism' (logical): Whether females cannibalised
 (scored as 1) or not (scored as 0) O. 'first.ootheca.weight'
 (numerical): The weight of the first ootheca (in g), measured two weeks
 after oviposition P. 'second.ootheca.weight' (numerical): The
 weight of the second ootheca (in g), measured two weeks after oviposition
 Q. 'total.ootheca.weight' (numerical): The total weight of the
 first and second ootheca (in g) #### 4. Note: Variable M was only used for
 a supplementary calculation and analysis ### E.
 LC_-_fecundity_test_low_vs_high.csv #### 1. Number of variables: 8 #### 2.
 Number of cases/rows: 29 (one row per female) #### 3. Variable List: A.
 'treatment' (categorical): The condition treatment that females
 belonged to (two levels: 'low' and 'high') B.
 'female.id' (categorical): Replicate-level identifier for
 females (29 levels) C. 'female.length' (numerical): The length
 of the female prothorax at adulthood (in mm) D. 'female.weight'
 (numerical): Female body weight (in g), measured 3.5 weeks into the high
 and low feeding regimes E. 'weighing.date' (date): The date that
 females were weighed F. 'female.condition' (numerical):
 Condition score of females, calculated as the residuals of the linear
 regression of the natural logarithm of 'female.weight' and the
 natural logarithm of 'female.length' G.
 'age.at.allocation' (integer): Female age at feeding regime
 allocation (i.e., number of days from last moult to feeding allocation) F.
 'first.ootheca.weight' (numerical): Weight of the first ootheca
 (in g), measured two weeks after oviposition