Tolerance and functional response of Neoseiulus californicus (McGregaor) to starvation stress

The ability to endure starvation is important for predatory mite survival and its effectiveness as biological control agent. We studied the longevity and functional response of the prodator mite Neoseiulus californicus (McGregaor) under starvation stress. N. californicus individuals were treated as three groups: the mites were provided with nothing (group I), with fresh bean leaves (group II), and with water (group III) to the larvae, protonymphs, deutonymphs, adult males and females. Functional response of N. californicus to Tetranychus urticae Koch eggs was evaluated after starvation for 0 h, 24 h, 48 h, and 72 h. Results showed that all life stages of N. californicus in group III had the longest survival time among the three groups. Adult females had the strongest ability to endure starvation with a mean survival time of 8.16 d. Females had the ability to lay eggs, but the number of eggs laid was less than a mean of 1.2 eggs per female in the three starvation groups. N. californicus exhibited a Holling’s Type II functional response at all hunger levels. The handling time (Th) and attack rate (α) of the predator were not significantly different in all hunger levels. Predation rate of starved 0 h to 72 h initially increased and then decreased. The highest predation rate was recorded when the predators were starved for 24 h.

The predatory mite Neoseiulus californicus (Acari: Phytoseiidae) does not respond for volatiles of maize infested by Tetranychus urticae (Acari: Tetranychidae)

Among the plants defense mechanisms, the induction and emission of volatile organic compounds, which can be used to attract natural enemies, such predators insects. Although well studied, the induction of plant volatiles that attract natural enemies can vary according to intensity of infestation of herbivores and the species of host plant. We investigated the olfactory behavioral responses of the predatory mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) to the volatiles of infested maize (Zea mays) plants by the two-spotted spider mite Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) in early and advanced infestations. The Bt (Viptera) maize cultivar Impact® was used for tests the behavior of N. californicus. After initial and advanced infestations, the phytophagous mites T. urticae were removed, and the plants were tested using a “Y” olfactometer. The following treatments were evaluated: air vs. air, uninfested plants vs. air, uninfested plants vs. plants infested with 10 females of T. urticae, uninfested plants vs. plants infested with 100 females of T. urticae, uninfested plants vs. plants infested with 200 females of T. urticae and plants infested with 10 vs. plants infested with 200 females of T. urticae. The predatory mite N. californicus did not show preference to the treatments tested, suggesting that maize plants infested by T. urticae do not induce volatiles capable of attracting the predatory mite N. californicus. We concluded that N. californicus is not attracted by maize plants infested by T. urticae.

Efectos letales y subletales de acaricidas sintéticos en ácaros depredadores de la familia Phytoseiidae

El objetivo de esta investigación fue evaluar en laboratorio la toxicidad de acaricidas sintéticos en los ácaros Phytoseiidae Amblyseius swirskii y Neoseiulus californicus, y determinar mediante meta-análisis de estudios publicados los efectos subletales de acaricidas en especies de la familia Phytoseiidae. En las evaluaciones de laboratorio se observó que spirodiclofen, fenpiroximato y acequinocyl mostraron los valores más bajos de CL50 y CL90. Al comparar las concentraciones recomendadas en campo, spirodiclofen tendría mayor efecto tóxico sobre los ácaros depredadores evaluados, que sobre ácaros fitófagos. Por su parte, el meta-análisis mostró que todos los acaricidas, tienen efectos negativos en la supervivencia, fecundidad y periodo de oviposición. Los acaricidas inhibidores de respiración mitocondrial denominados METI I, presentaron mayores efectos negativos en estas variables, en especial en los géneros Neoseiulus y Phytoseius. Los acaricidas sintéticos de nueva generación tienen efectos tóxicos letales y efectos subletales en ácaros depredadores de la familia Phytoseiidae.

Neoseiulus californicus (Acari: Phytoseiidae) shows good predation potential when reared on an artificial diet supplemented with Tetranychus cinnabarinus

To evaluate the predation potential of Neoseiulus californicus (McGregor) reared on an artificial diet as a biological control agent for Tetranychus cinnabarinus (Boisduval), life table and functional response studies were performed. To identify alternative food sources for rearing N. californicus, we compared the nutritional values of the basal diet (composed of sucrose, yeast extract, honey, tryptone and egg yolk), meridic diet (add T. cinnabarinus on the basis of basal diet) and control (T. cinnabarinus). Further, the predation ability of N. californicus continuously reared for ten consecutive generations on a meridic diet to control T. cinnabarinus was assessed. The results showed that N. californicus fed the basal and meridic diets successfully completed development from eggs to adults, but they did not oviposit when fed the basal diet. The high fecundity (41.00 eggs per female) and intrinsic rate of increase (0.2357 d-1) recorded in the meridic diet group suggests that it is a suitable diet for N. californicus rearing. Additionally, a functional response (type II) was observed in N. californicus reared on the meridic diet. We found that when the predator was reared on the meridic diet, the estimated maximum attack rate (T/Th) associated with larvae was 58.67, which was only 13.94% lower than the control (68.17). The 10th generation of N. californicus did not lose the ability to capture and kill T. cinnabarinus when fed on meridic diet. In conclusion, N. californicus reared on the meridic diet containing T. cinnabarinus showed good predation ability; therefore, this diet may be beneficial for the mass production of N. californicus.

Insectoacricides And Insecticides And Neoseiulus Californicus (Parasitiformes, Phytoseiidae) Safe And Great Application In Protected Ground

Toxicity study for predatory mites Neoseiulus californicus pesticides legally permitted for use against pests (aphids, thrips, whiteflies) in the Russian Federation on protected ground is an urgent task. The purpose of determining the possibility of safe use of chemical treatments with drugs (Vertimeca (abamectin), Clipper (bifenthrin), Novaktion (malathion), Admiral (pyriproxyfen), Aktara (thiamethoxam), Confidor (imidacloprid) and Bitoxibacillin (Bacillus thuringiensis var. thuringiensis) against the background of the acariphagus.