Eggfruit caterpillar or poroporo fruit borer, Sceliodes cordalis (Doubleday) (Lepidoptera: Pyralidae), is not established in Tasmania despite being common at cooler sites in New Zealand. The pest is common around Christchurch, New Zealand which offers less heat than Launceston or Melbourne. Adults occasionally migrate to Tasmania and larvae are occasionally detected at the quarantine barrier in imported commercial fruit. Suitable host plants occur widely in Tasmania including seasonal commercial and domestic crops. The immature stages have not been detected in Tasmania and evidence for breeding in Victoria is scarce. All captures of S. cordalis moths in Tasmania are coincidental with known long-distance migratory species and airflows favourable for migration across Bass Strait. Published and unpublished data for the duration of natural and laboratory life cycles are used with a day-degree development model to explore some scenarios of establishment in Tasmania. This indicated potential for 1–2 generations when initiated from December-February oviposition. The results provide another example to biosecurity entomologists of a pest that has failed to establish, even ephemerally, in Tasmania despite presence of host plants, a mainland breeding distribution attenuating southwards into Victoria and marginally suitable climate in Launceston, Tasmania. A previous example is cabbage-centre grub, Hellula hydralis Guenée (Lepidoptera: Pyralidae) (Hill 2012). Arguably, the distribution and development model of S. cordalis shares some similarities with that of Queensland fruit fly (Qfly), Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), a quarantinable pest of great consequence. Sceliodes cordalis regularly performs a natural experiment of attempting establishment in Tasmania and may represent an indicator of likelihood for B. tryoni via propagules of larvae in imported fruit.
Cite this article as:
Hill, L. (2015) Eggfruit caterpillar, Sceliodes cordalis (Doubleday) (Lepidoptera: Pyralidae), a vagrant moth and indicator for likelihood of Queensland fruit fly establishment in Tasmania? Plant Protection Quarterly 30(1), 27-39.