Spider mite (Tetranychus urticae)
Pests of African violets, as well as houseplants are divided into three large categories:
1) Mites;
2) INSECT;
3) Worms.
In the following I will present some information about each individual species.
They belong to the category of mites:
– Spider mite (Tetranychus urticae);
– The flat spider (Tenuipalpidae);
– The transparent spider (Tarsonemidae);
– Acarianul Parasitiformes.
Spider mite (Tetranychus urticae) is the most ubiquitous of all mites. It has a round body of yellow color, brownish or vierzuie covered with rare but quite developed brushes. On the sides of the body may have spots of darker colors. Females, that hibernates in winter, can be reddish or even red. Males are somewhat smaller than females and have a slightly elongated body.
All representatives of this species, one way or another, they weave a barely visible canvas around the affected areas of the plant, where they got the name of spiders.
The eggs laid by the females are round whitish or yellowish in color and have an almost transparent content. Once the embryo begins to develop, the contents of the egg become cloudy, and the eggs turn yellow.
The development of the embryo depends on the temperature in the room. At a temperature of +15 °С the embryo develops within 15 days, and at a temperature of +30°С only in 2-3 days.
From the fertilized eggs come out females, of the unfertilized males. Larvae of the spider mite, unlike adults, have three pairs of legs. After the first stage of development, larvae turn into nymphs and have 4 pairs of legs, just like adults. The life expectancy of a generation depends on the temperature and is 30-36 days or 7-8 days.
In autumn, a large part of the nymphs turn into females that hibernate throughout the winter without feeding. Many of them migrate to the nearby spaces located either at a height, or in the basement. So, precautions taken against these mites do not always give the expected results.
During the heat, a large part of the females cease to feed and migrate in search of shelter until the end of the heat. This makes the fight against these pests even more difficult.
Signs of contamination and measures taken against this pest.
Spider mite (Tetranychus urticae) it feeds on the contents of plant cells. Its presence is signaled by the small white spots on the leaves ( especially those on the bottom of the leaf) and a spider web woven around the plant or certain parts of the plant. In case of massive contamination, leaves become bleached due to multiple lesions. The plant is totally covered with a spider web, and on the extremities of the leaves and flower buds accumulates a mass of moving bodies.
A good part of the plant cells are destroyed, the surface and the intensity of photosynthesis are reduced, the plant is increasingly weakened and more exposed to infections of any type.
Although it feeds on plant cells, mite painjen (Tetranychus urticae) is also a carrier of infections. In the specialized literature it is mentioned that the parasite in question is the carrier of gray mold spores and viral infections of many species in agricultural crops and in the category of decorative plants.
The insecticide does not work on this pest. In the fight against it it is recommended to use acaricides or insectoacaricides. Unfortunately, there is no acaricide that does not endanger human health. Hence, it is very important to work with them with increased attention and at regular intervals, following exactly all the precautionary measures presented in the safety data sheet.
The most harmless acaricides, used in apartments are VERMITEC, FITOVERM, NEORON, DEMITAN, OMIT, SUNMITE, NISSORUN, BYE-BYE, MITIGAN, etc. or insecto-acaricides: TALSTAR etc..
These products are very effective if used properly. Unfortunately, they do not have an effect on eggs and females in hibernation, thus, the treatment with acaricide once stops temporarily or not at all the attack of the spider mite.
The preparations in question do not work if the room temperature is below +18 °С and if the solution prepared from them has been kept for more than a day.
At a temperature of + 20°С, a minimum of 3 sprinklings with an interval of 9-10 days are required, and at a temperature of + 30°С, 3-4 sprinklings with an interval of 3-4 days are required. Otherwise, females that have emerged from the egg, reach maturity in 6-7 days at a temperature of + 30 ° С and will lay eggs again.
And the APOLLO 50 SC acaricide can be successfully used in the extermination of this mite. APOLLO 50 SC has a very good ovicid effect and is effective in combating young larval stages in many species of mites. The excellent action of the product determines the reduction of the number of treatments compared to the standard combat programs.
Still, the largest 'producers' of spider mites remain to be evenings where the temperature and humidity of the air is conducive to their mass development.