Interactions between the predatory mite Typhlodromalus aripo and the entomopathogenic fungus Neozygites tanajoae and consequences for the suppression of their shared prey/host Mononychellus tanajoa

Abstract

The predatory mite Typhlodromalus aripo and the entomopathogenic fungus Neozygites tanajoae, both introduced from Brazil for control of the cassava green mite (CGM) Mononychellus tanajoa, now co-occur in cassava fields in Benin. However, studies on interactions between these two natural enemies and how they might affect CGM biological control are lacking. We determined in screenhouse experiments the effects of single and combined releases of N. tanajoae and T. aripo on CGM suppression. In the single natural enemy treatment, both T. aripo and N. tanajoae significantly reduced CGM densities, but the results of the predator (T. aripo) are more quickly measurable than those of the pathogen (N. tanajoae) in our short-term experiment. The level of CGM suppression in the combined natural enemy treatment was reduced considerably compared with T. aripo-alone, but only slightly when compared with N. tanajoae alone, with a simultaneous reduction in T. aripo and N. tanajoae abundance or prevalence. In a laboratory experiment, T. aripo fed more on N. tanajoae-infected CGM than on healthy CGM and its oviposition and survival were reduced when fed on the former compared with the latter, which can help in explaining the reduction in numbers of T. aripo and consequently the considerable loss in suppression of CGM in the combined natural enemy treatment in the screenhouse experiment. Together, the screenhouse and the laboratory experiments predicted negative interactions between the two natural enemies with negative consequences for CGM biological control. Long-term field observations and rigorous field experiments that simultaneously manipulate T. aripo and N. tanajoae abundance and prevalence are needed to validate the prediction of this study.

Susceptibility of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae), a Eucalyptus pest, to entomopathogenic fungi

“…The use of fungi can complement the biological control of T. peregrinus with Cleruchoides noackae (Hymenoptera: Mymaridae), Hemerobius bolivari (Neuroptera: Hemerobiidae), and Chysoperla externa (Neuroptera: Chrysopidae) as the main natural enemies reported for this pest (Nadel and Noack, 2012;Souza et al, 2012;Garcia et al, 2013). However, entomopathogenic fungi can cause adverse effects to the biological life history parameters of natural enemies (Agboton et al, 2013;Wu et al, 2015). Thus, the application of entomopathogenic fungi should be carefully adjusted to complement the biological systems of pest control (Furlong, 2004;Oreste et al, 2016).…”

Provisioning predatory mites with entomopathogenic fungi or pollen improves biological control of a greenhouse psyllid pest

“…[76][77][78] Similarly, feeding on N. tanajoae-treated M. tanajoa reduced the survival rates and oviposition of the predatory mite T. aripo. 52 Also, B. bassiana dry residue significantly reduced the survival rates and fecundity of A. swirskii under laboratory conditions. 39 These negative effects of dry conidia on phytoseiid mites may be caused by secondary metabolites and toxins produced by B. bassiana during fungal infection, which might negatively influence the performance of predatory mites.…”

“…B. bassiana SZ‐26 conidia had no direct pathogenicity to the predatory mite N. barkeri – the conidia were not able to penetrate the cuticle of N. barkeri and could be ingested by N. barkeri , although the fungi had indirect harmful effects on the life table parameters and body size of N. barkeri when feeding on B. bassiana ‐treated F. occidentalis . Similarly, feeding on N. tanajoae ‐treated M. tanajoa reduced the survival rates and oviposition of the predatory mite T. aripo . Also, B. bassiana dry residue significantly reduced the survival rates and fecundity of A. swirskii under laboratory conditions .…”

Compatibility of Amblyseius swirskii with Beauveria bassiana: two potentially complimentary biocontrol agents

“…Interactions between arthropods and entomopathogens are however complex (Agboton et al 2013;Aqueel and Leather 2013) and the impact of sublethal effects is poorly understood (Pozzebon and Duso 2010;Seiedy et al 2012;Shipp et al 2012). The aim of this study was to establish the potential of the commercially available B. bassiana strain GHA to infect and kill A. swirskii under optimal conditions for the pathogen and to investigate the effects on specific population parameters when subjected to topical application of B. bassiana conidial suspensions and/ or dry residues on leaf discs.…”