The paper presents research results in the field of long-term forecasting of the phase state of the harmful non-gregarious locusts of Northern Kazakhstan. The major predictors of pests' phase state were developed based on modeling of their long-term abundance dynamics. Analyzing longstanding data of external factors (weather conditions and the area of chemical treatments) affecting the abundance dynamics of phytophaga, authors calculated the coefficients of regression equation. This may be one of the key factors in long-term forecasting of the phase state of abundance dynamics of harmful non-gregarious locusts in the Northern Kazakhstan regions. Also, based on the developed predictors, authors proved the area of agricultural lands to be treated at different phase states of studied phytophaga.

The paper considers the approaches and possibilities of using two types of simulation: the species distribution model and the ecological niche model. The study aimed to simulate favorable habitats and the potential spread of non-gregarious locust pests in North Kazakhstan based on satellite and ground data for preventive measures. The MaxEnt software was used to conduct the simulation. According to the species distribution model, high indicators of the habitat are predicted in the Pavlodar and Kostanay regions, on 69.9-100% of the studied territory. With the simulation of ecological niches for non-gregarious locust pests, the following class boundaries were determined for the transition from quantitative to qualitative indicators from I (85-100%) to IV (0-50%), which indicates the zones of the probability of pest attack from a higher indicator to a lower one. According to the fundamental model, high indicators of the area of pest occurrence, that is, zones I and II, are located in the central and northern parts of the Pavlodar region. Here, the probability of non-gregarious locust occurrence of zone I and II with a ratio of 1:1 is observed in a slightly arid, moderately warm agro-climatic zone. In the southern part of the Kostanay region, the simulation predicts the probability of occurrence on zones I and II with a ratio of 1:2 in the moderately arid warm agro-climatic zone of this region. In the southern and southeastern parts of the Akmola region, the model predicts the probability of occurrence in zones I and II with a ratio of 1:3 in a slightly humid, moderately warm agro-climatic zone of the region. The considered species distribution model can be used as a modern tool for long-term forecasting of the spread of non-gregarious locust pests since it takes into account the peculiarities of the agricultural landscape. The fundamental niche model can be used in a long-term population forecast since it focuses more on the theoretical conditions of pest habitats.

The article presents the results of many years of research on the phytosanitary state of agricultural land for non-gregarious locust pests. As polyphagous pests, non-gregarious locusts are one of the key destabilizing factors in the production of economically important agricultural plants in the agricultural regions of Northern Kazakhstan. Research on the long-term population dynamics of non-gregarious locust pests to determine bioecological regularities and factors influencing them for early forecasting an increase in the number and rational planning of plant protection products is very relevant. The studies were carried out in 1999-2019 based on the use of data on the distribution of non-gregarious locusts in Akmola, Pavlodar, Kostanay and North Kazakhstan regions. Numerical indicators of pest colonization and abundance indices were used as diagnostic predictors characterizing the phase state of species in a given year, which made it possible to establish patterns of population dynamics of locusts. Based on the research results, the authors concluded that the expected onset of certain phases of the dynamics of the phytophagous population was not always preserved and was subject to change under the influence of environmental factors. The trend in the dynamics of the number of studied phytophages depends to a large extent on the weather conditions of the previous and current year, as well as on the full amount of volumes and compliance with the necessary procedures. The data obtained can be proposed as criteria for predicting the phase state of populations of non-gregarious locusts in Northern Kazakhstan to justify and plan protective measures, as well as to improve phytosanitary control over non-gregarious locusts.