Galendromus occidentalis (Acari: Phytoseiidae) life table parameters on Oligonychus yothersi (Acari: Tetranychidae) colonies and its behavior to odors of mites, avocado shoots volatiles and synthetic compounds

Abstract

The red mite, Oligonychus yothersi (McGregor) (Acari: Tetranychidae), is a serious pest of avocado (Persea americana Mill.) 'Hass' in Chile. Micro-coleopterans predators are observed in avocado orchards during outbreaks of O. yothersi, which are attracted by herbivore-induced plant volatiles (HIPVs). However, the damage to plants persists and new predators are needed. Due to its effectiveness and adaptability to dry climates, the western predatory mite Galendromus occidentalis (Nesbitt) (Acari: Phytoseiidae) has been adopted as a biological control agent on many crops. Ours objectives were to study the biological parameters of G. occidentalis preying on O. yothersi in controlled conditions and its attraction to volatile compounds from avocado shoots, live preys and four synthetic doses of methyl salicylate (MeSA) and ocimene using a Y-tube olfactometer. We found a net reproductive rate (R0) 34.41 offspring female -1 , intrinsic rate of increase (rm) 0.19 females female -1 d -1 , finite rate of increase (λ) 1.21 females female -1 , mean generation time (T) 18.45 d, and doubling time (DT) of 3.61 d. Immature phytoseiids took 7.32 d to reach adulthood with 90% survival. Female longevity and fecundity were 36.27 d, and 59 eggs female -1 , respectively. Phytoseiids show no attraction to O. yothersi volatiles or volatiles of O. yothersi-infested avocado shoots. Nevertheless, females showed a preference for synthetic MeSA and ocimene at 100 μg mL -1 . Our findings indicate that O. yothersi is a potential diet to rear G. occidentalis, and MeSA and ocimene could be used in lures to manipulate its behavior in avocado orchards.

Efficiency of entomopathogenic bacteria and fungi on Oligonychus yothersi in vitro and on Persea americana Mill. plants

“…The pest O. yothersi has been reported as a polyphagous and severe species in several countries of the world (Pinto et al, 2012;Ceballos et al, 2022), plant damage is expressed in the reduction of photosynthetic activity, the consequence of which is excessive defoliation of the plant when attacks are severe (Rioja et al, 2018;Rioja et al, 2019). Among the most susceptible varieties of Persea americana are Hass and Fuerte, with a direct consequence on fruit quality and yield (Ceballos et al, 2022).…”

“…The pest O. yothersi has been reported as a polyphagous and severe species in several countries of the world (Pinto et al, 2012;Ceballos et al, 2022), plant damage is expressed in the reduction of photosynthetic activity, the consequence of which is excessive defoliation of the plant when attacks are severe (Rioja et al, 2018;Rioja et al, 2019). Among the most susceptible varieties of Persea americana are Hass and Fuerte, with a direct consequence on fruit quality and yield (Ceballos et al, 2022). This is the foliar pest with the highest incidence during the autumn and summer season (Yang et al, 2015;Bayu et al, 2017;Rioja et al, 2019) whose symptoms are tanning and leaf fall, because the mite pierces the leaf with its chelicerae in the form of a stylet and sucks the cellular contents (Rioja et al, 2018;Chiaradia et al, 2021).…”