Mr Trevor Volp1, Mr Adam Quade1, Dr Melina Miles1, Professor Myron Zalucki2, Professor Michael Furlong2

1Qld Department Agriculture & Fisheries, Toowoomba, Australia, 2The University of Queensland, St Lucia, Australia

Biography:

Trevor Volp is a research scientist at QDAF and PhD candidate at the University of Queensland.

Abstract:

In 2020 Fall Armyworm (FAW; Spodoptera frugiperda; Lepidoptera: Noctuidae) was detected in Australia and there was substantial panic around the extensive number of crop species that were about to be destroyed by the pest. The oft-repeated number of purported FAW host plants stands at 353 plant species, which includes most broadacre and horticultural crops. This large number is often exploited by entomologists in papers, presentations, and particularly funding applications. But if it is a credible estimate of the number of true host plants of FAW is debateable. Further, such a number is of limited use from a pest management perspective without understanding the cause and context of damaging FAW infestations. Since the incursion of FAW four years ago, an interesting pattern of crop infestations has occurred – Zea mays (i.e. maize and sweet corn varieties) regularly experience heavy infestations, other summer grass crops (e.g. sorghum) are semi-regularly infested, and there is a ‘long tail’ of so called non-preferred crops that have been sporadically infested, sometimes with major consequences to individual growers. In this presentation we report the results of laboratory and glasshouse studies examining the relationships between FAW and purported host plants, present results of a carbon isotope survey of field-collected moths to examine what plants (C3 or C4) generate FAW populations and discuss the importance of proper investigations and record keeping when building a pest’s ‘host list’. Our understanding of the FAW host plant relationships is limited, and further work in this area is required to guide management strategies.