Sex differences in immunity in a natural population of bush-cricket (Orthoptera: Phaneropterinae)
Immune defense often differs between sexes, where females generally exhibit higher individual immunity than males. Such sexually dimorphic immune defense stems from differential investment into reproduction as females allocate more resources into mating. Contrary to prevailing predictions, some studies have found that females exhibit a weaker immune response than males. In this study, I examined both humoral (phenoloxidase activity and lytic activity) and cellular (encapsulation ability) immune parameters including cuticular melanization in a field population of a bush-cricket (Isophya reticulata) that is an endemic species in the northeastern part of Turkey. As expected, females showed a higher phenoloxidase activity than males, whereas there were no sex differences in lytic activity. Males expressed a higher encapsulation response than females. These results indicated that sex differences in immunity may be variable and females may not always exhibit higher immunity than males. Another interesting finding of this study was a positive relationship between stridulatory file length, phenoloxidase activity, and wing melanization. This finding demonstrated a connection between size differences in stridulatory apparatus that affect sexual signaling and immune response.
KeywordsSex-based immunity Phenoloxidase Lytic activity Encapsulation Isophya Bush-cricket
I would like to thank Nilgün Tokgöz for her assistance in the laboratory work. The author is also grateful to Kenneth M. Fedorka and Ian Kutch for their comments that improved the quality of this manuscript.
Compliance with ethical standards
Conflict of interest
The author declares he has no conflict of interests.
- Adamo SA, Jensen M, Younger M (2001) Changes in lifetime immunocompetence in male and female Gryllus texensis (formerly G. integer): trade-offs between immunity and reproduction. Anim Behav 62:417–425. https://doi.org/10.1006/anbe.2001.1786
- Fedorka KM, Sevgili H (2014) The influence of nuptial feeding and sperm transfer on the immunological cost of reproduction in the ground cricket Al lonemobius socius. Physiol Entomol 39:89–93. https://doi.org/10.1111/phen.12051
- Gershman SN, Barnett CA, Pettinger AM, Weddle CB, Hunt J, Sakaluk SK (2010b) Give 'til it hurts: trade-offs between immunity and male reproductive effort in the decorated cricket, Gryllodes sigillatus. J Evol Biol 23:829–839. https://doi.org/10.1111/j.1420-9101.2010.01951.x CrossRefPubMedGoogle Scholar
- Kavanagh MW (1987) The efficiency of sound production in two cricket species, Gryllotalpa australis and Teleogryllus commodus (Orthoptera, Grylloidea). J Exp Biol 130:107–119Google Scholar
- Kutch IC, Sevgili H, Wittman T, Fedorka KM (2014) Thermoregulatory strategy may shape immune investment in Drosophila melanogaster. J Exp Biol 217:3664–3669. https://doi.org/10.1242/jeb.106294
- Sevgili H (2004) A revision of Turkish species of Isophya Brunner von Wattenwyl (Orthoptera: Tettigoniidae: Phaneropterinae). Hacettepe University, Ankara, p 387Google Scholar
- Sevgili H (2016) İki çalı çekirgesi üzerinde doğal bağışıklık parametrelerinden fenoloksidaz aktivitesi ile litik aktivitenin ve hemolimfteki protein konsantrasyonunun yöntemsel olarak belirlenmesi. Akademik Ziraat Dergisi 5:51–62Google Scholar
- Team RC (2012) R: a language and environment for statistical computing. R Foundation Statistical Computing, Vienna, AustriaGoogle Scholar
- Vincent CM, Gwynne DT (2014) Sex-biased immunity is driven by relative differences in reproductive investment. Proc R Soc B 281:20140333. https://doi.org/10.1098/rspb.2014.0333