Disentangling mite predator‐prey relationships by multiplex PCR

Abstract

Gut content analysis using molecular techniques can help elucidate predator-prey relationships in situations in which other methodologies are not feasible, such as in the case of trophic interactions between minute species such as mites. We designed species-specific primers for a mite community occurring in Spanish citrus orchards comprising two herbivores, the Tetranychidae Tetranychus urticae and Panonychus citri, and six predatory mites belonging to the Phytoseiidae family; these predatory mites are considered to be these herbivores' main biological control agents. These primers were successfully multiplexed in a single PCR to test the range of predators feeding on each of the two prey species. We estimated prey DNA detectability success over time (DS50), which depended on the predator-prey combination and ranged from 0.2 to 18 h. These values were further used to weight prey detection in field samples to disentangle the predatory role played by the most abundant predators (i.e. Euseius stipulatus and Phytoseiulus persimilis). The corrected predation value for E. stipulatus was significantly higher than for P. persimilis. However, because this 1.5-fold difference was less than that observed regarding their sevenfold difference in abundance, we conclude that P. persimilis is the most effective predator in the system; it preyed on tetranychids almost five times more frequently than E. stipulatus did. The present results demonstrate that molecular tools are appropriate to unravel predator-prey interactions in tiny species such as mites, which include important agricultural pests and their predators.

When do predatory mites (Phytoseiidae) attack? Understanding their diel and seasonal predation patterns

“…However, this importance was accredited due to its higher abundance in the field (seven times higher than that of P. persimilis ) given that E. stipulatus was far less effective than expected as it preferred to feed on other food sources whereas P. persimilis specimens mostly preyed on tetranychids. Accordingly, P. persimilis was the most effective biological control agent in the system (Pérez‐Sayas et al ., ). However, the tetranychid specialist Neoseiulus californicus (McGregor), which is usually present in this system at densities above those of P. persimilis (Aguilar‐Fenollosa et al ., ), was barely found during these field samplings, which took place mainly during the day in summer (Pérez‐Sayas et al ., ).…”

“…In Spanish citrus orchards, there is a complex acarofauna population comprising two main herbivores, the Tetranychidae Tetranychus urticae Koch and Panonychus citri (McGregor), and several predatory mites belonging to the Phytoseiidae family (Abad‐Moyano et al ., ; Aguilar‐Fenollosa et al ., ,b; Jaques et al ., ). Recently, our research group developed a multiplex PCR method for disentangling trophic relationships among these mites (Pérez‐Sayas et al ., ). With this molecular tool, we were able to identify the two tetranychids and the six most abundant phytoseiid species in Spanish clementine orchards (Aguilar‐Fenollosa et al ., ,b; Jaques et al ., ) and to detect both tetranychid mite species in the predators’ gut content.…”

“…With this molecular tool, we were able to identify the two tetranychids and the six most abundant phytoseiid species in Spanish clementine orchards (Aguilar‐Fenollosa et al ., ,b; Jaques et al ., ) and to detect both tetranychid mite species in the predators’ gut content. However, prey detection changed over time and depended on the predator–prey combination (Pérez‐Sayas et al ., ). Furthermore, corrected predation values, used to quantify the relative importance of each predator (Greenstone et al ., ), highlighted the higher importance of the omnivorous Euseius stipulatus (Athias‐Henriot) when compared with the T. urticae specialist Phytoseiulus persimilis Athias‐Henriot (Pérez‐Sayas et al ., ).…”

Efectos de las condiciones abióticas sobre las interacciones entre tres depredadores de Tetranychus urticae con distintos hábitos alimenticios

“…Although we assume that our samplings are representative of the species abundance in our trees, we cannot exclude some circadian rhythms occurring in our system, which may have hindered the estimation of the real abundance of these species. Indeed, Pérez-Sayas et al (2017) demonstrated that the three phytoseiids included in our study exhibit diel and seasonal predatory patterns when feeding on Tetranychus urticae which may explain why N. californicus, which is usually present in clementine orchards at densities above those of P. persimilis (Aguilar-Fenollosa et al, 2011b), was barely found during samplings performed around midday in summer (Pérez-Sayas et al, 2015). Moreover, additional semifield trials where N. californicus was released demonstrated that this species is prone to seek refuge in citrus branches and trunks (Pina et al, 2013).…”

“…As E. stipulatus is the most abundant phytoseiid species in Valencian clementine orchards (Garcia-Marí et al, 1991;AbadMoyano et al, 2009a;Aguilar-Fenollosa et al, 2011b), one might consequently expect T. urticae problems to worsen with Climate Change. However, as under these conditions P. persimilis appears as the most tolerant species (Table 3.3) and this species is also considered as the most efficient predator of T. urticae in clementines (Pérez-Sayas et al, 2015), the situation could be reverted. However, as N.…”