Eiphosoma laphygmae, a classical solution for the biocontrol of the fall armyworm, Spodoptera frugiperda?
The fall armyworm, Spodoptera frugiperda, an American Lepidoptera, is invasive in Africa and Asia and currently one of the most damaging cereal pests in the tropics. The ichneumonid parasitoid, Eiphosoma laphygmae, is a potential classical biological control agent. We assessed existing knowledge on biology, identified natural distributions, collated reported parasitism rates from field studies and determined which other parasitoids co-occurred. We discussed the suitability of E. laphygmae for classical biological control as well as identified limitations and knowledge gaps. We conducted a systematic literature review and had 185 hits, retaining 52 papers. Reports on the natural distribution of E. laphygmae were restricted to the American tropics, ranging from North-East Mexico to Sao Paulo State, Brazil. There were only two single and unconfirmed records of it on other hosts, suggesting that the parasitoid may be specific to S. frugiperda, but this needs confirmation. In fields where E. laphygmae occurred naturally, it was the second most important contributor to fall armyworm mortality, after the braconid Chelonus insularis. On average, E. laphygmae parasitized 4.5% of fall armyworm in field studies. The highest parasitism rates were from Costa Rica (13%) and Minas Gerais, Brazil (14.5%). However, these parasitism rates are probably largely underestimated because of likely biases in sampling and parasitism rate calculations. Eiphosoma laphygmae appeared to establish better in more diverse, weedy systems. As African farming systems often have high diversity, this may favour the establishment and parasitism of E. laphygmae if eventually introduced as a classical biological control agent.