Egg size-dependent fertilization mediates sex allocation in a sexually dimorphic haplodiploid thrips species

The data set describes egg size mediated sex allocation and mating regulated reproductive investment in both laboratory and field-collected populations of Kelly’s citrus thrips, <i>Pezothrips kellyanus </i>(Thysanoptera: Thripidae). It demonstrates the size of eggs produced by three different mother types according to their mating status and their offspring sex ratio: virgins [= V], mated females producing only male offspring [= M(♂)] and mated females, producing female and male offspring [= M(♀+♂)]. The offspring is also categorized in four types based upon their sex and mother type: sons of M(♀+♂) [= SV], sons of M(♂) [= SM(♂)], sons of M(♀+♂) [= SM(♀+♂)] and daughters of M(♀+♂) [= DM(♀+♂)]. According to the data, <i>P. kellyanus</i> exhibits an egg size-dependent fertilization, and shows a previously unknown mechanism underlying sex allocation in haplodiploid insects for the first time. Moreover, the data demonstrates larger minimum, maximum and average egg volume (but similar clutch size) in M(♀+♂) compared to the other mother types and, consequently, a higher ERI in this mother type, suggesting that this is triggered by mating. However, this higher ERI occurs at the expense of smaller life-time fecundity due to a shorter reproductive life-span in M(♀+♂). Finally, the data reveals a positive correlation between egg size and offspring fitness parameters such as survivorship, larva and adult size. This indicates that the egg size variation is due to differential maternal nutrient and energy allocation.