Two-spotted spider mite in Cyprus: ineffective acaricides, causes and considerations

Abstract

Growers of greenhouse roses in Cyprus have recently reported failures of several acaricides against twospotted spider mite (Tetranychus urticae Koch). To verify the cause of these failures we evaluated the eVectiveness of seven acaricides against two rose and two cucumber spider mite populations in the laboratory. The acaricides included in our study represented the most important mode of action groups registered for use in greenhouses on the island. Label rates of all seven acaricides (abamectin, clofentezine, dicofol, fenbutatin oxide, fenazaquin, propargite and milbemectin-a product under registration) caused close to 100% mortality in the cucumber populations, but signiWcantly lower mortality in the two rose populations. Mortality never exceeded 65% in the Wrst rose population and 20% in the second population for any acaricide, suggesting development of resistance. The higher frequency of acaricide applications in roses and the perennial nature of the crop, that sustains genetically similar populations for long periods of time, may have facilitated the development of resistance. Judicious use of newer acaricides with distinct modes of action as they become registered may help control resistant spider mite populations in roses and other ornamental crops. Additionally, adoption of a mode of action labeling scheme of pesticides and training of growers on alternation of products will facilitate long term sustainable spider mite management in Cypriot agriculture.

Resistance to acaricides in Italian strains of Tetranychus urticae: toxicological and enzymatic assays

“…Nevertheless, problems with T. urticae are frequently reported in protected crops, in particular in rose greenhouses, where many recently introduced acaricides show a progressive loss of effectiveness after only a few years of use. This situation seems to reflect that reported in other countries (e.g., Stavrinides and Hadjistylli 2009;Khajehali et al 2011). European floricultural production accounts for 40-50% of the world production (19.5 billion in 2009).…”

Lethal and sublethal effects of fluralaner on the two‐spotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae)

“…No significant difference in mean generation time (T) was observed among the different treatments. 10 34.97 ± 2.31 b 2.97 ± 0.11 a 11.57± 0.42 ab LC 30 27.57 ± 1.01 c 2.95 ± 0.13 a 9.60± 0.38 b §Values are shown as mean ± SE. Lower case letters indicate significant difference between different treatments (P < 0.05).…”

“…TSSM has high reproductive rates and a short life history, develops quickly and can lead to total yield loss in host crops if not be controlled in a timely manner . TSSM has developed resistance to a broad range of chemical classes of acaricides and is considered as ‘resistance champion’ in terms of the total number of compounds to which its populations have become resistant . For example, the eggs, larvae and female adults of TSSM have developed 56 771‐, 42 378‐ and 4989‐fold resistance to abamectin, respectively .…”

“…4 TSSM has developed resistance to a broad range of chemical classes of acaricides and is considered as 'resistance champion' in terms of the total number of compounds to which its populations have become resistant. [5][6][7][8][9][10][11][12] For example, the eggs, larvae and female adults of TSSM have developed 56 771-, 42 378-and 4989-fold resistance to abamectin, respectively. 8 Furthermore, female adults of TSSM exhibit 885.93-, 1920.11-, > 187 500-and > 245-fold resistance to bifenazate, propargite, hexythiazox and clofentezine, respectively.…”

The effects of timing and rate of release on population growth of Phytoseiulus persimilis reared on Tetranychus urticae

“…However, spider mites develop resistance to pesticides rapidly (Croft and van de Baan 1988) and TSM resistance to over 80 pesticides has been reported to date from around the world, spanning most major chemical groups (APRD 2007). TSM resistance problems are of special interest in Cyprus, where a recent study suggested that some populations are resistant to the great majority of acaricides registered for use on the island (Stavrinides and Hadjistylli 2009).…”