Natural enemies that impact pest populations must be understood in order to build integrated pest control strategies and to understand the most important aspects affecting pest dynamics. Haloxylon ammodendron (C. A. Mey.) Bunge is an important perennial plant species extensively used in sand stabilization and wind prevention in arid areas. This study aimed to determine the main defoliators that damage H. ammodendron and the parasitoid complex associated with them. Twelve species of defoliators were found in Northern Xinjiang, and Teia dubia (Tauscher) (Lepidoptera: Lymantriidae), Scrobipalpa sp. (Lepidoptera: Gelechiidae), and Eucharia festiva Hüfnagel (Lepidoptera: Arctiidae) were the dominant pests. T. dubia is the predominant defoliator with three generations a year. Northwest China, Central Asia, and the Mediterranean region are potentially suitable habitats for T. dubia in the world, while Xinjiang is the primary distribution area in China. Parasitoids belonging to seven species and four families were reared from the larvae of T. dubia, they were all endoparasitoids and koinobiont. Cotesia sp. (Hymenoptera: Braconidae) is the dominant parasitoid and prefer to parasitic in the 3rd–5th instar larvae. The present study provides the basis for understanding the species composition and natural enemies of lepidopteran defoliators. It will be an effective tool for the integrated pest management programs of H. ammodendron forest.

Saline soils contain multiple types of salt, each of which may exert a different effect on seed germination and seedling growth of plants. The effects of five types of salt on the initial growth of Haloxylon ammodendron, a shrub found on both saline and non-saline areas in deserts of China, were investigated. Seeds were incubated at 20°;C in the dark in a solution (0 to –5.1 MPa) of a salt (NaCl, MgCl2, CaCl2, Na2SO4 or MgSO4) or polyethylene glycol (PEG)-6000, or in a salt (NaCl or MgCl2) or PEG solution containing a low concentration of CaCl2. Seed germination, seedling growth and cation (Na+, Mg2+, Ca2+ and K+) contents of seedlings were examined. Each salt had a different effect on seed germination, seedling growth and influx and outflux of cations in the seedlings. In both NaCl and MgCl2 treatments, the addition of low concentrations of CaCl2 favoured seed germination and seedling growth, and reduced K+ outflux from seedlings, but caused no appreciable decrease in the influx of Na+ or Mg2+ into seedlings. Marked abnormalities in seedlings were found only in treatments with Mg2+ salts, but these effects were completely alleviated by a low concentration of Ca2+ (Ca2+/Mg2+ = 0.012). The different responses of the initial growth in H. ammodendron to different isotonic salt solutions were attributed to differences among salt components in membrane permeability, toxicity and effects on functions of the plasma membrane and/or the cell wall.