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8FRUIT TREES MCDANIEL SPIDER MITE
X.A. Ergasheva1
The article although the McDaniel spider mite is less polyphagous than the two spotted spider mite, its host range is nevertheless rather diverse. It turns a dull ivory hue just before hatching, and the embryo's crimson eyespots are evident. McDaniel spider mite eggs and two spotted spider mite eggs are indistinguishable. The estimate of mites per leaf is calculated by dividing the total number of mites on the plate by the number of leaves brushed onto that plate
Key words: spider mite, fruits, egg, apple, pear, protonymph, deutonymph, female, male, adult.
McGregor's Tetranychus mcdanieli (Acari: Tetranychidae) The McDaniel spider mite was initially discovered on raspberries in Michigan in 1930, although it has only become a nuisance on tree fruits in the Pacific Northwest, Utah, and select sections of California, generally in drier locations. It has received the greatest attention as an apple pest in central Washington, where it has been a problem since the 1930. As a result of major disruptions in biological control, widespread epidemics occurred in the late 1950 and early 1960. These epidemics prompted the first studies on integrated mite management, which has subsequently been effectively adopted in the majority of Washington apple orchards. While the McDaniel mite was the predominant outbreak species in central Washington at the time, it has become increasingly rare in subsequent years.
Although the McDaniel spider mite is less polyphagous than the two spotted spider mite, its host range is nevertheless rather diverse. Most deciduous tree fruits (apple, pear, sweet and sour cherry, prune, peach, and apricot), some field and vegetable crops (squash, asparagus, alfalfa, clover), and a variety of weeds are affected (mallow, milkweed, knotweed, ragweed, mustard, dock, wild buckwheat, wild lettuce). Red Delicious apple, sweet cherry, and apricot were shown to be better hosts for McDaniel spider mites than pear, peach, and sour cherry in a study on egg counts and survival.
Figure 1. Adult female McDaniel spider mite Figure 2. McDaniel spider
mite immature (E. Beers)
The egg is round and is approximately 1/150 inch (0.13 mm) in diameter. It is transparent when originally laid but darkens over time. It turns a dull ivory hue just before hatching, and the embryo's crimson eyespots are evident. McDaniel spider mite eggs and two spotted spider mite eggs are indistinguishable.
The larva is roughly the same size as the egg and has three pairs of legs. It is colorless until it begins to eat, at which point it takes on a greenish colour from leaf chlorophyll. The quiescent stage measures around 1/12 inch (0.20 mm) in length. The protonymph is oval in shape, dark green in color, and has four pairs of legs. The female measures 1/100 inch (0.25 mm) in length, while the male is somewhat shorter. The
1 Ergasheva Xonoyim Abdukahhorovna - Senior lecturer basic doctoral student of the Department of Plant Protection, Tashkent State Agrarian University.
deutonymph, like the preceding stage, has four pairs of legs and is often the same color and form. At this stage, the female, which is about 1/70 inch (0.35mm) long, may easily be separated from the male. The male has a slim, tapering abdomen and is noticeably smaller than the female.
The adult female is around 1/60 inch (0.44 mm) long, whereas the male is only approximately 1/80 inch (0.29) long. Adult females, like deutonymphs, may be identified from males by their form. The female's belly is wide and round, whereas the male's abdomen is slim and pointed. The black dots on the abdomen that distinguish this species can be found at all stages, although they are more noticeable in the older stages. Because of the variety in both species, the initial stages may be difficult to differentiate from twospotted spider mite. The McDaniel spider mite has many pairs of spots, some of which are always seen in the posterior region of the abdomen.
Figure 3. Fruit and foliar damage caused by McDaniel spider mite
Figure 4. Diapausing McDaniel spider mites on apple fruit (E. Beers)
Monitoring. Mites are difficult to spot at first because to their small size, but the results of heavy feeding will be seen without having to step out of the automobile. Mites are visible on leaves, but most individuals will require a hand lens to tell the difference between species. The presence of reddish marks on the fingers after touching infected plants is generally indicative of European red mite. Monitoring mite populations can be done in a variety of ways. The first is an in-person assessment. Examine 10 leaves from each of 10 trees each block (a total of 100 leaves) with a hand lens and count the number of mites. If the population is large, this is time-consuming and prone to counting
errors. However, if other tools are not available, it can provide a reasonable evaluation of mite numbers.
A common method is to gather leaves in the field and transport them to a location where a leaf brushing machine and a microscope may be employed. The leaf brushing machine is a device with opposable rollers covered in soft bristles that brushes mites from the leaf surface down to a rotating glass plate coated with a somewhat sticky material (e.g., liquid detergent). The mites are immobilized on the plate's surface, and the microscope assists in the identification of individual species and stages. A paper grid with 20 wedges imprinted on it is usually put beneath the glass plate to aid in counting. There is a printable grid available for usage. The estimate of mites per leaf is calculated by dividing the total number of mites on the plate by the number of leaves brushed onto that plate. When population density is high, just a portion of the plate is tallied (one-half or one-quarter).
This approach is likewise time-consuming and prone to mistake, but it is likely the most accurate of the options offered. It has been the conventional approach for determining economic harm for the most of the time.
References
1.Brunner, J. F., & Smith, L. O. (1981). Control of Mcdaniel Spider on Cherry, 1980. Insecticide and Acaricide Tests, 6(1), 31-31.
2.Downing, R. S. (2019). Petroleum oils in orchard mite control. Journal of the Entomological Society of British Columbia, 64, 10-13.
3.Downing, R. S., & Jack, I. D. (2019). The specificity of Binapacryl, a dinitro miticide, against the European red and McDaniel spider mites. Journal of the Entomological Society of British Columbia, 60, 19-21.
4.Downing, R. S., & Jack, I. D. (2019). The specificity of Binapacryl, a dinitro miticide, against the European red and McDaniel spider mites. Journal of the Entomological Society of British Columbia, 60, 19-21.
5.Flexner, J. L., Westigard, P. H., Gonzalves, P., & Hilton, R. (1991). The effect of groundcover and herbicide treatment on twospotted spider mite density and dispersal in southern Oregon pear orchards. Entomologia experimentalis et applicata, 60(2), 111-123.
6.Jones, V. P. (1990). Sampling and dispersion of the twospotted spider mite (Acari: Tetranychidae) and the western orchard predatory mite (Acari: Phytoseiidae) on tart cherry. Journal of economic entomology, 83(4), 1376-1380.
7.Nielsen, G. L. (1958). Biology of the McDaniel mite, Tetranychus mcdanieli McGregor in Utah. Journal of Economic Entomology, 51(5), 588-592.
8.Roy, M., Brodeur, J., & Cloutier, C. (2003). Effect of temperature on intrinsic rates of natural increase (rm) of a coccinellid and its spider mite prey. BioControl, 48(1), 57-72.
9.Roy, M., Brodeur, J., & Cloutier, C. (2005). Seasonal activity of the spider mite predators Stethorus punctillum (Coleoptera: Coccinellidae) and Neoseiulus fallacis (Acarina: Phytoseiidae) in raspberry, two predators of Tetranychus mcdanieli (Acarina: Tetranychidae). Biological Control, 34(1), 47-57.
10.Tanigoshi, L. K., Murray, T. A., & Gerdeman, B. S. (2003). Spider mites on red raspberry. Cooperative Extension, Washington State University.
© X.A. Ergasheva, 2022.
