Journal of Insect Behavior

, Volume 30, Issue 3, pp 308–317 | Cite as

Do Male Cook Strait Giant Weta Prudently Allocate Sperm?

Article

Abstract

Sperm production is costly and so males are expected to prudently allocate sperm to matings in a manner that maximizes their fitness. Sperm competition hypotheses predict that when facing increased sperm competition risk males should increase their investment in ejaculates. In contrast, when facing high future mating opportunities, males are expected to decrease their sperm investment in the current mating. This is because males should keep in reserve an amount of sperm proportional to their expected future mating opportunities. We experimentally tested whether male Cook Strait giant weta (Anostostomatidae: Orthoptera: Deinacrida rugosa) phenotypically adjust their investment in ejaculates in relation to their perceived risk of sperm competition and future mating opportunities. D. rugosa is a large flightless orthopteran insect in which males pass multiple spermatophores to females during a day-long mating bout. Contrary to expectation, we found that low female availability (i.e. increased sperm competition risk) had no effect on male resource allocation to sperm (i.e. number of spermatophores) compared to controls whereas, contrary to expectation, males experiencing high female availability increased their ejaculate investment by transferring significantly more spermatophores to their mates. Our results might be a consequence of males being insensitive to increased presence of rival males, reducing their allocation to sperm under increasingly risky circumstances, or due to females prolonging copulations when their perceived future mating opportunities are low.

Keywords

Sexual selection spermatophore repeated mating sperm competition ejaculate expenditure sex ratio allocation 

Notes

Acknowledgements

We thank Frank Higgott, Susan Caldwell, and Nio Mana (New Zealand Department of Conservation, Marlborough Sound) for assistance while this research was being conducted on Maud Island. We are grateful to Frank and Susan for collecting and dissecting the giant weta that were caught in mouse traps. Two referees provided valuable criticism and advice. This research was supported by Discovery Grants from the National Science and Engineering Research Council (NSERC) of Canada to CDK and DTG.

Supplementary material

10905_2017_9622_MOESM1_ESM.docx (43 kb)
ESM 1(DOCX 43 kb)

References

  1. Barrett LT, Evans JP, Gasparini C (2014) The effects of perceived mating opportunities on patterns of reproductive investment by male guppies. PLoS One 9:e93780–e93788. doi:10.1371/journal.pone.0093780 CrossRefPubMedPubMedCentralGoogle Scholar
  2. Brown WD, Gwynne DT (1997) Evolution of mating in crickets, katydids and wetas (Ensifera). Bionomics of Grasshoppers, Katydids, and their Kin 58:1242–1250.Google Scholar
  3. Cornwallis CK, Birkhead TR (2006) Social status and availability of females determine patterns of sperm allocation in the fowl. Evolution 60:1486–1493CrossRefPubMedGoogle Scholar
  4. delBarco-Trillo J (2011) Adjustment of sperm allocation under high risk of sperm competition across taxa: a meta-analysis. J Evol Biol 24:1706–1714. doi:10.1111/j.1420-9101.2011.02293.x CrossRefPubMedGoogle Scholar
  5. Engqvist L, Reinhold K (2005) Pitfalls in experiments testing predictions from sperm competition theory. J Evol Biol 18:116–123CrossRefPubMedGoogle Scholar
  6. Esfandi K, He XZ, Wang Q (2015) Flirtation reduces males’ fecundity but not longevity. Evolution 69:2118–2128. doi:10.1111/evo.12715 CrossRefPubMedGoogle Scholar
  7. Galvani A, Johnstone RA (1998) Sperm allocation in an uncertain world. Behav Ecol Sociobiol 44:161–168. doi:10.2307/4601563?ref=search-gateway:de8b483cb513b7f0d30dcb07c8f1ff6d CrossRefGoogle Scholar
  8. Hooper AK, Wegener BJ, Wong BBM (2016) When should male squid prudently invest sperm? Anim Behav 112:163–167. doi:10.1016/j.anbehav.2015.12.005 CrossRefGoogle Scholar
  9. Jackman S (2015) Pscl: classes and methods for R developed in the political science computational laboratory, Stanford University. Department of Political Science, Stanford University, Stanford R package version 1.4.9. URL http://pscl.stanford.edu/
  10. Kelly CD (2006) The relationship between resource control, association with females and male weapon size in a male dominance insect. Ethology 112:362–369. doi:10.1111/j.1439-0310.2006.01193.x CrossRefGoogle Scholar
  11. Kelly CD (2015) Male-biased sex ratios and plasticity in post-insemination behaviour in the New Zealand stick insect Micrarchus hystriculeus. Behaviour 152:653–666. doi:10.1163/1568539X-00003247 CrossRefGoogle Scholar
  12. Kelly CD, Gwynne DT (2016) The effect of condition on mate searching speed and copulation frequency in the Cook Strait giant weta. Behav Ecol Sociobiol 70:1403–1409. doi:10.1007/s00265-016-2150-y CrossRefGoogle Scholar
  13. Kelly CD, Jennions MD (2011) Sexual selection and sperm quantity: meta-analyses of strategic ejaculation. Biol Rev 86:863–884. doi:10.1111/j.1469-185X.2011.00175.x CrossRefPubMedGoogle Scholar
  14. Kelly CD, Bussiere LF, Gwynne DT (2008) Sexual selection for male mobility in a giant insect with female-biased size dimorphism. Am Nat 172:417–423. doi:10.1086/589894 CrossRefPubMedGoogle Scholar
  15. Kelly CD, Bussiere LF, Gwynne DT (2010) Pairing and insemination patterns in a giant weta (Deinacrida rugosa: Orthoptera; Anostostomatidae). J Ethol 28:483–489. doi:10.1007/s10164-010-0211-7 CrossRefGoogle Scholar
  16. Kelly CD, Tawes BR, Worthington AM (2014) Evaluating indices of body condition in two cricket species. Ecol Evol 4:4476–4487. doi:10.1002/ece3.1257 CrossRefPubMedPubMedCentralGoogle Scholar
  17. Lüpold S, Manier MK, Ala-Honkola O et al (2011) Male Drosophila melanogaster adjust ejaculate size based on female mating status, fecundity, and age. Behav Ecol 22:184–191. doi:10.1093/beheco/arq193 CrossRefGoogle Scholar
  18. McIntyre M (2001) The ecology of some large weta species in New Zealand. In: Field LH (ed) The biology of wetas, king crickets and their allies. CABI International, Wallingford, pp 225–242Google Scholar
  19. Parker GA (1970) Sperm competition and its evolutionary consequences in insects. Biol Rev 45:525–567CrossRefGoogle Scholar
  20. Parker GA (1998) Sperm competition and the evolution of ejaculates: towards a theory base. In: Birkhead TR, Møller AP (eds) Sperm competition and sexual selection. Academic Press, New York, pp 3–54CrossRefGoogle Scholar
  21. Parker GA (2016) The evolution of expenditure on testes. J Zool 298:3–19. doi:10.1111/jzo.12297 CrossRefGoogle Scholar
  22. Parker GA, Ball M (2005) Sperm competition, mating rate and the evolution of testis and ejaculate sizes: a population model. Biol Lett 1:235–238CrossRefPubMedPubMedCentralGoogle Scholar
  23. Parker GA, Pizzari T (2010) Sperm competition and ejaculate economics. Biol Rev 85:897–934. doi:10.1111/j.1469-185X.2010.00140.x CrossRefPubMedGoogle Scholar
  24. Peig J, Green AJ (2009) New perspectives for estimating body condition from mass/length data: the scaled mass index as an alternative method. Oikos 118:1883–1891. doi:10.1111/j.1600-0706.2009.17643.x CrossRefGoogle Scholar
  25. Peig J, Green AJ (2010) The paradigm of body condition: a critical reappraisal of current methods based on mass and length. Funct Ecol 24:1323–1332. doi:10.1111/j.1365-2435.2010.01751.x CrossRefGoogle Scholar
  26. Quinn GP, Keough MJ (2002) Experimental design and data analysis for biologists. University Press, CambridgeGoogle Scholar
  27. R Core Team (2016) R: a language and environment for statistical computing. Version 3.2.5. R Foundation for Statistical Computing, Vienna, Austria. Available from https://www.r-project.org/
  28. Reinhold K, Kurtz J, Engqvist L (2002) Cryptic male choice: sperm allocation strategies when female quality varies. J Evol Biol 15:201–209CrossRefGoogle Scholar
  29. Richards AM (1973) A comparative study of the biology of the giant wetas Deinacrida heteracantha and D. fallai (Orthoptera: Henicidae) from New Zealand. J Zool 169:195–236. doi:10.1111/j.1469-7998.1973.tb04554.x CrossRefGoogle Scholar
  30. Rondeau A, Sainte-Marie B (2001) Variable mate-guarding time and sperm allocation by male snow crabs (Chionoecetes opilio) in response to sexual competition, and their impact on the mating success of females. Biol Bull 201:204–217CrossRefPubMedGoogle Scholar
  31. Sal Moyano MP, Gavio MA, Luppi T (2015) Different sperm allocation strategies in two populations of the semiterrestrial crab Neohelice granulata(Brachyura, Grapsoidea, Varunidae). Mar Ecol 37:737–749. doi:10.1111/maec.12338 CrossRefGoogle Scholar
  32. Schielzeth H (2010) Simple means to improve the interpretability of regression coefficients. Methods Ecol Evol 1:103–113CrossRefGoogle Scholar
  33. Watts C, Stringer I, Thornburrow D et al (2009) Morphometric change, distribution, and habitat use of Cook Strait giant weta (Deinacrida rugosa: Orthoptera: Anastostomatidae) after translocation to Matiu-Somes Island. N Z Entomol 32:59–66CrossRefGoogle Scholar
  34. Watts C, Empson R, Thornburrow D, Rohan M (2012) Movements, behaviour and survival of adult Cook Strait giant weta (Deinacrida rugosa; Anostostomatidae: Orthoptera) immediately after translocation as revealed by radiotracking. J Insect Conserv 16:763–776. doi:10.1007/s10841-012-9461-8 CrossRefGoogle Scholar
  35. Wedell N, Gage MJG, Parker GA (2002) Sperm competition, male prudence and sperm-limited females. Trends Ecol Evol 17:313–320CrossRefGoogle Scholar
  36. Wegener BJ, Stuart-Fox DM, Norman MD, Wong BBM (2013) Strategic male mate choice minimizes ejaculate consumption. Behav Ecol 24:668–671. doi:10.1093/beheco/ars216 CrossRefGoogle Scholar
  37. Worthington AM, Jurenka RA, Kelly CD (2015) Mating for male-derived prostaglandin: a functional explanation for the increased fecundity of mated female crickets? J Exp Biol 218:2720–2727. doi:10.1242/jeb.121327 CrossRefPubMedGoogle Scholar
  38. Zeileis A, Kleiber C, Jackman S (2008) Regression models for count data in R. J Stat Softw 27(8):1–25 URL http://www.jstatsoft.org/v27/i08/ CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2017

Authors and Affiliations

  1. 1.Département des sciences biologiquesUniversité du Québec à MontréalMontrealCanada
  2. 2.Department of BiologyUniversity of Toronto at MississaugaMississaugaCanada

Personalised recommendations