Jewel Wasp Biology Kadeen Johns Barry K Rhoades

Jewel Wasp Biology Kadeen Johns Barry K. Rhoades

Nasonia Vitripennis Life Cycle

n n n Several host species, including Sarcophaga bulatta Complete metamorphosis with ~14 day developmental cycle Characteristics of Nasonia Jewel wasps are haplodiploid – gender determined by vitripennis ploidy n n Flightless, haploid males have short wings - mate at eclosion site Diploid females have longer wings, larger bodies – locate and oviposit hosts Mating takes place immediately after eclosion Three different stock eye colors - wild, scarlet, and oyster

Nasonia vitripennis Reproduction n Haplodiploid genetics of eye color Mated female (stores sperm) Diploid fertilized egg Haploid unfertilized egg Female offspring Male offspring Female Phenotypes: Wild Scarlet Oyster +. +/+. + +. st/+. st oy. +/oy. + +. +/+. st +. +/oy. + +. st/oy. + Wild Oyster +. + Male Phenotypes: Scarlet +. st oy. +

Maternal Determination of Progeny Gender in Nasonia vitripennis n n n Female stores sperm after mating in spermatheca Female can deposit either fertilized or unfertilized eggs Female can detect prior ovipositions into host puparium and control sex ratio of offspring (F 1) during oviposition For single oviposition, females mate with brothers upon eclosion Ideal F 1 sex ratio differs depending on oviposition exclusivity and sequential order – facultative sex ratio adjustment n n n First wasp (primary oviposition) -> predominantly female progeny – maximizes # of F 2 secnd generation female offspring Subsequent wasps (superoviposition) -> relatively more males – outcompete primary wasp’s few male F 1 progeny for reproductive access to F 1 females Multiple female wasps directly competing -> relative number of male progeny should increase with number of competing wasps

Distinguishing Females from Males sorting pupae – to isolate virgin females

Distinguishing Females from Males

Eye Color Variants

Facultative Sex Ratio Adjustment Based on Oviposition Sequence n n Single fly puparium exposed sequentially to 2 female wasps Day 1 – female wasp 1, Day 2 – female wasp 2 Purebred eyecolor stocks used to determine offspring parentage Balanced design with repetitions n n n W 1 S 2 x 4, S 1 W 2 x 4 – 4 groups O 1 S 2 x 4, S 1 O 2 x 4 – 3 groups Data included: n n n if and only if female progeny from both parental stocks 16 out of 56 fly puparia -> 462 wasps C 2 = 36. 5, d. f. = 1, p <. 001 Offspring Male Female M/F Ratio 1 st Wasp 78 225 0. 35 2 nd Wasp 86 73 1. 18

Facultative Sex Ratio Adjustment Based on Female Competition n n Single fly puparium exposed to 1 or more female wasps concurrently 1, 2, 4, or 8 female wasps – 4 day exposure Repetitions – 7 sets x 4 conditions Data included: n n n if and only if female progeny eclosed 23 out of 28 fly puparia -> 1320 wasps C 2 = 26. 1, d. f. = 3, p <. 001 Offs pring Male Female M/F Ratio 1 Wasp 95 150 . 63 2 Wasps 157 115 1. 37 4 Wasps 234 147 1. 59 8 Wasps 249 173 1. 44