The influence of host plant variation and intraspecific competition on oviposition preference and offspring performance in the host races of Eurosta solidaginis

Abstract

Summary 1. A series of experiments was conducted to measure the impact of plant genotype, plant growth rate, and intraspecific competition on the oviposition preference and offspring performance of the host races of Eurosta solidaginis (Diptera: Tephritidae), a fly that forms galls on Solidago altissima and Solidago gigantea (Asteraceae). Previous research has shown that both host races prefer to oviposit on their own host plant where survival is much higher than on the alternate host plant. In this study, neither host race showed any relationship between oviposition preference and offspring performance in choosing among plants of their natal host species. 2. The larval survival of both host races differed among plant genotypes when each host race oviposited on its natal host species. In one experiment, altissima host race females showed a preference among plant genotypes that was not correlated with offspring performance on those genotypes. In all other experiments, neither the altissima nor gigantea host race demonstrated a preference for specific host plant genotypes. 3. Eurosta solidaginis had a preference for ovipositing on rapidly growing ramets in all experiments, however larval survival was not correlated with ramet growth rate at the time of oviposition. 4. Eurosta solidaginis suffered high mortality from intraspecific competition in the early larval stage. There was little evidence, however, that females avoided ovipositing on ramets that had been attacked previously. This led to an aggregated distribution of eggs among ramets and strong intraspecific competition. 5. There was no interaction among plant genotype, plant growth rate, or intraspecific competition in determining oviposition preference or offspring performance.

Aceitação e preferência de frutos para oviposição em duas populações de Ceratitis capitata (Diptera, Tephritidae)

“…SADEGHI & GILBERT (1999) registraram a existência de uma variabilidade individual, em relação à existência de correlação entre preferência e performance, dentro de uma população e YAMAGA & OHGUSHI (1999) constataram que, em alguns casos, ocorre uma variação anual na correlação positiva preferência-performance no campo. Parece haver predominância dessa correlação em insetos especialistas em comparação a insetos polífagos (BARROS & ZUCOLOTO, 1999;CRAIG et al, 2000), pois estes últimos têm uma menor capacidade de discriminação de hospedeiros. Isso seria uma vantagem em ambientes imprevisíveis e facilitaria a mudança e a adaptação a novos hospedeiros (FLETCHER & PROKOPY, 1991).…”

Oviposition Behavior of Ceratitis capitata Wiedemann (Diptera: Tephritidae): Association Between Oviposition Preference and Larval Performance in Individual Females

“…The existence of a possible positive correlation between the choice of a host for oviposition and offspring performance has been extensively studied over the last few years and has been demonstrated in some species (Barros & Zucoloto 1999, Gu & Walter 1999, Huk & Kuhne 1999, but not in others (Underwood 1994, Berdegue et al 1998, Cronin & Abrahamson 1999, Craig et al 2000.…”

Effect of Achillea millefolium Strips and Essential Oil on the European Apple Sawfly, Hoplocampa testudinea (Hymenoptera: Tenthredinidea)

“…To avoid intraspecific competition for a limiting resource, numerous phytophagous species have developed mechanisms such as the use of visual and chemical clues to discriminate previous attacks by competitors [45]. Under laboratory conditions, H. testudinea adults, oviposited significantly less frequently in blossoms containing oviposition wounds and eggs by conspecifics than in healthy, uninfected ones [46].…”