Occurrence and Control Methods of Goji Gall Mite Disease

In mid-to-late August 2002, in the goji berry production area on the border between Julu and Longyao, goji gall mite disease broke out severely, causing great losses to the vast number of goji berry growers.

Damage symptoms: most obvious on the leaves, with densely packed yellow-green nearly circular raised dots on the damaged parts, and the leaves are distorted, similar to a viral disease, with plant growth severely stunted; the leaves and tender stems are inedible, and the fruits are deformed, reducing both yield and quality.

Using a blade to cut open the small bumps on the leaves and taking out the adult mites from inside, under a microscope the adult mites are long conical and orange-yellow. After consulting the literature, this mite mainly overwinters in the axillary buds within the tree crevices of other plants near goji berry planting sites. In mid-April of the following year, when the winter buds of goji berry just begin to show green, the overwintering mites begin to emerge from dormancy and become active; in late May to early June, when goji berry leaves unfold, large numbers of the emerged adult mites move onto new goji berry leaves to lay eggs, and the hatched young mites bore into the leaf tissue to form galls; from mid-August to mid-to-late September, the damage reaches its peak. In mid-November, as the temperature drops, the adult mites enter overwintering. In addition, it was also found that varying numbers of adult mites were attached to the abdomens and tarsal segments of the legs of aphids and psyllids.

Control methods: the early overwintering period and the period after overwintering of the adult mites are the key control periods. When adult mites appear in large numbers, spray pesticide promptly to kill them, so as to reduce the density of the pest mites; spray 50% Shaman Dan suspension concentrate at 600 times, or Baiman Kuisha at 1000 times, or 1.8% abamectin at 3000-4000 times. In addition, according to the experience of local old farmers: by grasping the local period when gall-forming adult mites are exposed or the activity period of the emerged adult mites, using ultra-low-volume spraying, spraying a 1:1 mixture of 50% dipterex-propyl oil mist agent and diesel oil, using 200 grams of the pesticide solution per mu gives a better effect.