Neoseiulus cucumeris (Oudemans)

NovljanK, Monica, K, Tanja Bohinc, KreiterK, Serge, K, Ismail Döker & TrdanK, Stanislav, 2023, The indigenous species of predatory mites (Acari: Phytoseiidae) as biological control agents of plant pests in Slovenia, Acarologia 63 (4), pp. 1048-1061 : 1052-1053

Neoseiulus cucumeris (Oudemans)

Neoseiulus cucumeris ( Figure 3 ) was first described by Oudemans in 1930 based on the material collected from Cucumis melo L. ( Cucurbitaceae ) in Bure, Meurthe et Moselle, France.

It is a cosmopolitan species and its natural populations were reported in about 50 countries in

Asia, Europe, America, and Australia ( Demite et al. 2023). It has been reared on a commercial scale since 1985, and utilized to control several pest species in particular T. tabaci and F.

occidentalis ( Knapp et al. 2018 ; UVHVVR 2022b). It is now become one of the top four phytoseiid mites used as biological control agents ( Knapp et al. 2018). Products based on N.

cucumeris are available in the Slovenian market ( UVHVVR 2022d). In Slovenia, N. cucumeris was found for the first time in a single location in an intensive apple orchard between 1997

and 2003 ( Miklavc 2006). It is an abundant phytoseiid species in the northeastern part of the country and is mainly found in cucumbers and peppers Capsicum (annuum L.) ( Milevoj 2011).

Similar to N. barkeri , N. cucumeris is also known as a type IIIe generalist predator from soil-litter habitats ( McMurtry et al. 2013). Like many other generalist phytoseiid mites, N.

cucumeris can be reared on acarid mites. Its predation and reproduction potentials were proven on Polyphagotarsonemus latus (Banks) , Phytonemus pallidus (Banks) , T. urticae , and also on fungi ( Gerson et al. 2003). It is also can feed on different kinds of pollens and establish a remarkable population before pest arrival ( Ranabhat et al. 2014).

These predatory mites prefer warm temperatures for their development, with the lower temperature and relative humidity consecutively thresholds being around 8 °C and 65%. Above that, the higher the temperature the faster their development until around 30 °C. At 35 °C only

50% of the eggs hatch and 90% of the larvae will not survive in two days. Mating is essential for N. cucumeris reproduction and must be repeated several times because egg-laying females only produce eggs for around 20 days after their emergence, and then they die. The success of N. cucumeris against thrips depends on the size of the prey larvae. First-instar thrips larvae are taken easily compared to the second-instar larvae, as well as the larvae from smaller thrips species. On optimum conditions, an adult predatory mite can consume around six first instar thrips larvae a day ( Malais and Ravensberg 2004).

In a laboratory study conducted by et Li al. (2021), N. cucumeris was fed with the eggs of Tyrophagus curvipenis Fain and Fauvel ( Acari : Acaridae ) as an alternative food source.

On this diet, N. cucumeris needs approximately six days to complete the juvenile stage with a prey density of at least 60 eggs, while at lower food density they die as deutonymphs because of starvation. The larvae are not predacious, whereas the protonymphs and deutonymphs are actively searching for food. In general, the higher the prey population resulted in higher predation, with up to 66.30 eggs preyed out of 80 T. curvipenis eggs provided. It was also found that at the same prey density, the predator with conspecifics ate significantly fewer eggs compared to the lone predator.

Figures

Figure 3 Adult female ofNeoseiulus cucumeris (photo: Institut Agro Montpellier).