How Predatory Mites Respond to Eggs and Young Nymphs of a Common Plant Pest

Greg Howard
14th June, 2024

How Predatory Mites Respond to Eggs and Young Nymphs of a Common Plant Pest

Image Source: Natural Science News, 2024

Key Findings

  • Researchers at Inner Mongolia Agricultural University studied two predatory mites, Neoseiulus setarius and Neoseiulus barkeri, for controlling the goji berry pest Bactericera gobica
  • Both mite species showed a type II functional response, meaning they can effectively reduce pest populations, especially at lower densities
  • Neoseiulus setarius was more efficient, consuming more prey and having a higher attack rate and lower handling time than Neoseiulus barkeri, making it a better candidate for biological control
The goji berry psyllid, Bactericera gobica Logniova, poses a significant threat to goji berry plants (Lycium barbarum L.), which are valued for their use in traditional Chinese medicine and food. Currently, chemical control remains the predominant method to manage this pest. However, researchers at the Inner Mongolia Agricultural University have identified two predatory mites, Neoseiulus setarius Ma, Meng & Fan and Neoseiulus barkeri Hughes, that could offer a biological control alternative[1]. To evaluate the potential of these mites in controlling B. gobica, the researchers conducted a study to compare the functional responses of N. setarius and N. barkeri when feeding on different densities of B. gobica eggs and 1st instar nymphs. Functional response refers to the relationship between the density of prey and the rate at which a predator consumes them. The study was carried out at a controlled temperature of 25ºC ± 1ºC, and prey densities ranged from 2 to 32 individuals. The results revealed that both predatory mite species exhibited type II functional responses on eggs and 1st instar nymphs of B. gobica. A type II functional response is characterized by a rapid increase in the number of prey consumed as prey density increases, followed by a plateau where the consumption rate stabilizes due to the predator's handling time. This type of response suggests that both mite species could effectively reduce pest populations, particularly at lower pest densities. Among the two species, N. setarius demonstrated superior predation capabilities. It consumed more prey than N. barkeri across all prey density levels. Specifically, N. setarius showed the highest attack rate (α = 0.0283), the lowest handling time (Th = 1.1324 hours per prey), and the highest estimated maximum predation rate (T/Th = 21.19 prey per day) when fed with 1st instar nymphs of B. gobica. These metrics indicate that N. setarius can attack and consume prey more efficiently than N. barkeri, making it a more promising candidate for biological control of B. gobica. This study aligns with previous research on the effectiveness of predatory mites in controlling pest populations. For instance, Amblyseius largoensis has been found to significantly reduce populations of Raoiella indica by preferentially consuming its eggs, especially when prey densities are low[2]. Similarly, Amblyseius swirskii has shown potential for controlling Bemisia tabaci, with studies suggesting its effectiveness can be enhanced through mass rearing using alternative food sources[3]. Euseius concordis, another generalist predatory mite, has also demonstrated a type III functional response, effectively increasing prey consumption as prey density rises[4]. The findings from Inner Mongolia Agricultural University suggest that N. setarius and N. barkeri can be effective biocontrol agents against B. gobica, with N. setarius being the more efficient predator. These results support the broader use of predatory mites in integrated pest management (IPM) programs, offering a sustainable alternative to chemical control methods. By reducing reliance on chemical pesticides, such biological control strategies can help mitigate environmental impact and promote healthier agricultural practices.

AgricultureEcologyAnimal Science

References

Main Study

1) Functional responses of two species of predatory mites (Acari: Phytoseiidae) to eggs and first-instar nymphs of Bactericera Gobica Logniova (Homoptera: Psyllidae).

Published 13th June, 2024

https://doi.org/10.1007/s10493-024-00920-9

Related Studies

2) Prey-stage preferences and functional and numerical responses of Amblyseius largoensis (Acari: Phytoseiidae) to Raoiella indica (Acari: Tenuipalpidae).

https://doi.org/10.1007/s10493-011-9488-7

3) Potential of two populations of Amblyseius swirskii (Acari: Phytoseiidae) for the control of Bemisia tabaci biotype B (Hemiptera: Aleyrodidae) in Brazil.

https://doi.org/10.1007/s10493-015-9964-6

4) Functional response of Euseius concordis to densities of different developmental stages of the cassava green mite.

https://doi.org/10.1007/s10493-014-9823-x


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