Comparison of life tables between the solitary eumenid wasp Anterhynchium flavomarginatum and the subsocial eumenid wasp Orancistrocerus drewseni to evaluate the adaptive significance of maternal care

Abstract

Summary I compared life tables between the solitary eumenid wasp Anterhynchium flavomarginatumSmith and the subsocial eumenid wasp Orancistrocerus drewseniSaussure in Kyoto, Japan, during 1980–1983. The subsocial eumenid is parthenogenetic in this study area. There were 9 identified mortality factors in the solitary eumenid and 7 in the subsocial eumenid, 6 of which were common to the two eumenids. The important differences of mortality between the two eumenids were seen in the egg, larval, and prepupal stages. In the egg stage, mortality by the phorid fly Megaselia sp. was much lower in the subsocial eumenid (1.4%) than in the solitary eumenid (15.0%) likely because of the matenal care of the subsocial eumenid (progressive provisioning and other related behavior), which reduced predation pressure. In the larval stage, mortality by the miltogrammine fly Amobia distorta was also lower in the subsocial eumenid (8.1%) than in the solitary eumenid (23.8%) also probably because of the maternal care of the subsocial eumenid. A comparison of mortality in the two eumenids between the stable, long continuing natural nest sites and the additional temporal ones showed that the phorid fly remained near its birth place and parasitized stable nest sites. The miltogrammine fly followed returning eumenid wasps and parasitized those nest sites that have a high host density. In the prepupal stage, mortality by endogenous death was higher in the subsocial eumenid than in the solitary eumenid. Mortality due to the rhipiphorid beetle was also higher in the subsocial eumenid probably due to more frequent flower‐visits by the subsocial eumenid. The defense mechanism of the subsocial eumenid was discussed in relation to the evolution of subsociality.

Prevalence of Stylopization ofSphex ichneumoneus(L.) (Hymenoptera: Sphecidae) byParaxenos westwoodi(Templeton) (Strepsiptera: Xenidae)

“…Evans and Rates of strepsiteran parasitism have also been reported for several solitary Vespidae (Eumeninae). In Japan, Itino [16] documented an 8% stylopization rate in Anterhynchium flavomarginatum Smith; earlier, Iwata [17] had reported Pseudoxenos iwati Esaki as a parasite of this wasp. Pseudoxenos hookeri (Pierce) was present in 33% of nests and on 10% of individuals of Euodynerus foraminatus apopkensis (Robertson) in the United States [18].…”

The spatial patterns of parasitism of eumenid wasps, Anterhynchium flavomarginatum and Orancistrocerus drewseni by the miltogrammine fly Amobia distorta

“…In Kyoto, adult flies appear from June to October. The parasitizing behavior of female flies was studied by ITINO (1986). Seven host species were recorded by KURArmSm (1973) (6 species of Eumenidae and 1 of Sphecidae).…”

“…Of these 8 host species, eumenid wasps Anterhynchium flavomarginatum SMITH and O. drewseni were especially abundant in the study area. The general life histories of these two eumenid hosts have been discussed previously by ITINO (1986).…”

Behavior of the primitively social wasp Montezumia cortesioides Willink (Vespidae Eumeninae) and the origins of vespid sociality

“…FIELD & BRACE (1994) showed that in some sphecid wasps (Ammophila species) progressive provisioning effectively protects the vulnerable egg, by delaying the beginning of provisioning until the less vulnerable larval stage; and it protects the mother from investment in parasitized offspring because provisioning females detect and abandon parasitized larvae. Thus, progressive provisioning can enable a female to monitor the condition of young and to terminate maternal investment in the event of parasitic attack or illness (ITINO 1986, FIELD & BRACE 2004.…”