Two-spotted mite

Methods. Synthetic methods used to create the compounds described in this study and protocols used in the determination of toxicity to motile forms (mites) and eggs (activity expressed as LC50, ppm of foliar spray) have been published (6-10 1). The test organism was Tetranychus urticae (two-spotted mite). 

Successive resistances have driven control of the Boophilus cattle ticks all the way to OP compounds, and from them to chlor-phenamidine (chlordimeform) although it has been recently found that carbaryl is effective in cattle dips if synergized with piperonyl butoxide. The two-spotted mite has gone through a fantastic sequence of acaricides, the only ones to which resistance has not yet been reported being Pentac and the organo-tin compound Plictran. 

Fewer eggs were observed on the resistant parent than on the susceptible parent and fewer eggs were observed on the adaxlal versus the abaxlal leaf surfaces. Most species of two-spotted mites generally feed and oviposit on the abaxlal (lower) leaf surfaces (8). 

Two series of cyano-substituted ethyl thiopropyl enol phosphate insecticides (107 and 108) are synthesized by D Silva via phosphorylation of a precursor ketone 106.58 Some of the compounds are effective against the two-spotted mite.58... 

Table II. Activity of 5-aryl-2-dihalovinylthiophenes (1) on Two-spotted Mites.

Table VIII. Residual activity of light-activated miticides on two-spotted mites.

Fenpyroximate exhibits acaricidal and knockdown activities on phytophagous mites, such as Tetranychus urticae Koch (two-spotted spider mite) and Panony-chus citrP in citrus, apple, pear, peach, grape, etc. Fenpyroximate inhibits the mitochondrial NADH-Co Q reductase, which induces a decrease in ATP content and morphological changes in mitochondria and ultimately shows the acaricidal and knockdown activities. ... 

Resistance to organotin acaricides has been reported in several populations of spider mites. After cyhexatin and fenbutatin oxide were used for 10 to 17 years on pears and apples to control mites, populations of McDaniel spider mite (Tetranychus mcdanieli), two-spotted spider mite (T. urticae), and European red mite (Panonychus ulmi) slowly began to develop strains that were resistant to these chemicals (Croft et al. 1987). 

Beneficial insects associated with fruit orchards show different responses to diflubenzuron treatment (Broadbent and Pree 1984). Lacewings (Chrysopa oculata) in contact with leaves containing 300 mg/kg DW had reduced survival and inhibited molting of first instar larvae, but the assassin bug (Acholla multispinosa) was not affected by contact with treated leaves. Lacewings and other beneficial predator insects fed diflubenzuron-treated, two-spotted spider mites (Tetrany-chus urticae) for 3 days showed no adverse effects after 14 days (Broadbent and Pree 1984). 

It can also be made by nitrating diethyl phenyl phosphate below 0°. It is a red oil, almost insoluble in water, and Schrader found it effective against aphids, while Ball and Allen1 proved it active against the housefly, milkweed bug and cockroach. Later work showed it active against the two-spotted spider mite. 

Two examples of the remarkable potency of avermectin Bj are its LD9Q of 0.02 to 0.03 ppm against the two-spotted spider mite, Tetranychus urticae, when applied to bean plants as a foliar spray and its control of the red imported fire ant, Solenopsis invicta, when applied as a bait at a level as low as 25 to 50 mg per acre (19). 

Schuster et al. (21) identified cotton plant resistance to the two-spotted spider mite (Tetranycus urtlca Koch) by mass screening seedlings. Later Schuster and Lane (22) were able to show that high tannin lines, particularly TX-1055, showed resistance to this arachnid and the bollworm. 

Jeebhay, M.F., Baatjies, R., Chang, Y.S., Kim, Y.K., Kim, Y.Y., Major, V., Lopata, A.L. 2007. Risk factors for allergy due to the two-spotted spider mite (Tetranychus urticae) among table grape farm workers. International Archives of Allergy and Immunology 144(2) 143-149. 

JA and ethylene act synergistically in response to wounding.199 Arimura et al200 found that lima bean plants infested with two-spotted spider mites ( T. urticae) showed emission of ethylene. Synergistic effects of ethylene on JA-induced volatile production in lima bean leaves are reported.2 1... 

Pyrazole acaricides are derivatives of pyrazole. Tebufenpyrad is a broad-spectrum contact acaricide used for control of all stages of two-spotted spider mites and citrus red mites on cotton, fruits, vegetables, and ornamentals. It has an oral LD50 in rats of 595 mg/kg. Fenpy-roximate is an acaricide for control of important phytophagous mites on cotton, vegetables, fruit, vines, and others. 

---