TY - JOUR AB - We examined effects of seasonality, larval food availability and larval rearing density on sperm length, sperm transfer rates and body size in the bivoltine scorpionfly Panorpa vulgaris. Males of the first annual generation were larger and had larger sperm. Comparing individuals of two summer generations showed that adult males resulting from group bred, ad libitum fed larvae were larger but had smaller sperm than males resulting from singly kept, food deprived larvae. Thus, sperm size is not a simple function of body size. Instead, we suggest that sperm size modification was caused by varying rearing densities. Group bred individuals produced smaller sperm but transferred at higher rate. This indicates a trade-off between sperm number and sperm size as predicted by evolutionary models of sperm production. Given the strong influence of larval history in our present work, we recommend that future studies investigating the consequences of varying sperm competition risk or intensity on male gametic strategies should also control for larval history in order to avoid distorting effects. DA - 2009 DO - 10.14411/eje.2009.042 KW - sperm competition KW - spermatogenesis KW - ejaculate expenditure KW - Mecoptera KW - Panorpidae KW - sperm size KW - larval rearing density LA - eng M2 - 347 PY - 2009 SN - 1210-5759 SP - 347-352 T2 - European Journal of Entomology TI - Phenotypic plasticity in sperm traits in scorpionflies (Mecoptera: Panorpidae): consequences of larval history and seasonality on sperm length and sperm transfer UR - https://nbn-resolving.org/urn:nbn:de:0070-pub-23957792 Y2 - 2024-12-26T19:27:27 ER -