Non‐target effect of sprays to control California red scale (Aonidiella aurantii [Maskell], Hom., Diaspididae) on citrus red mite (Panonychus citri [McGregor], Acari, Tetranychidae)

Abstract

Five insecticides used to control California red scale, Aonidiella aurantii (Maskell), were evaluated in the field for their effect on California red scale and the non‐target pest, citrus red mite (Panonychus citri [McGregor]). Carbaryl, methidathion, parathion and chlorpyrifos were very effective against California red scale. NR 415 petroleum spray oil was less effective against California red scale than the organophosphates and carbamate. Carbaryl, methidathion and parathion caused an increase in citrus red mite population in both years of study. Chlorpyrifos caused an increase in citrus red mite population in one out of two years but did not result in as high an increase of citrus red mite numbers as did methidathion, parathion and carbaryl. Citrus red mite densities in the NR 415 petroleum oil treatments were as low or lower than in the untreated controls.

Conservation of natural enemy fauna in citrus canopies by horticultural mineral oil: Comparison with effects of carbaryl and methidathion treatments for control of armored scales

“…Many mechanisms have been proposed to explain numerous reports of the resurgence of pests or their replacement with the outbreak of other pests (such as phytophagous mites) after the application of pesticides. The proposed mechanisms are reduction of natural enemies, reduction in competition from other pests, altered host‐plant nutritional status, increased host‐plant attractiveness, changes in pest behaviour and hormesis (or hormoligosis), which is the physiological enhancement of pest fecundity (Hardin et al , 1995; Walker & Aitken, 1996; Dutcher, 2007). Hardin et al (1995) point out that there is no proof of any mechanism in many cases of resurgence or replacement; thus, when it does not take place, we may not infer without further proof that (say) natural enemies were ineffective before treatment.…”

“…Maintaining a high diversity of natural enemies is considered to be important for integrated pest management (IPM) in agricultural ecosystems (Herard & Shannon, 1985; McNeely et al , 1990) and in some programs, inundative releases of parasitoids or predators are required (Smith & Papacek, 1985; Moreno & Luck, 1992; Grafton‐Cardwell & Ouyang, 1995; Smith et al , 1997). However, application of pesticides (which may also be part of an IPM strategy) can also destroy the natural enemies of the pests, and moreover, it can also destroy the enemies of erstwhile relatively rare and harmless non‐target insects and mites that in turn can become pests (Huffaker & Messenger, 1976; Smith & Maelzer, 1986; DeBach & Bartlett, 1991; Walker & Aitken, 1996; Rehman et al , 2000).…”

“…Fortunately, it has been found that natural enemies of scale and some other pest insects are conserved if mineral oils are used (Walker & Aitken, 1996; Rae et al , 2000). Thus there is the opportunity to use IPM that combines biological control and intervention with mineral oils when necessary.…”

Lethal time of insecticides on the predator mite Neoseiulus fallacis (Acari: Phytoseiidae) following topical exposure

“…These results agree with those of Edward and Hodgson (1973) showing that carbamates were highly toxic to an important mite predator in citrus, Stethorus nigripes (Kapur) (Coleoptera: Coccinellidae). Similarly, a two-year field study by Walker and Aitken (1996) validated that carbaryl-elevated populations of citrus red mite, Panonychus citri (McGregor) (Acari: Tetranychidae), in California citrus. The toxicity of carbaryl against N. fallacis through direct sprays therefore is likely a primary contributor to any mite flaring associated with the application of this compound.…”

IPM-compatibility of foliar insecticides for citrus: Indices derived from toxicity to beneficial insects from four orders

“…3 & 4) and indicate high sensitivity to carbaryl and methidathion, as well as the pyrethroids fenpropathrin and bifenthrin. Carbaryl and methidathion were both found to elevate populations of citrus red mite, Panonychus citri, in both years of a two year field study in California citrus (Walker & Aitken, 1996). Morse & Bellows (1986) compared the toxicity of various insecticides over a range of concentrations to A. melinus and Cryptolaemus montrouzieri and generated concentrationmortality regressions to compare sensitivity.…”