It is one of the main forest pests in China, and the number of eggs laid by adults is directly related to the number of the next generation, which causes serious harm to forest trees. Based on the biological characteristics of P. longifolia, this paper will elaborate on its spawning dependence on temperature, and recommend the most suitable temperature range for spawning, so as to provide a reference for the prevention and control of P. longifolia.
To understand how to prevent and control it, we must first understand the living habits of the pine and black beetle.
It belongs to the family Coleoptera, and the adult body is 18-32 mm long and black or dark brown. It occurs in one generation a year, mainly harming Masson pine, Korean pine and other tree species. Adults are active from May to September, and females lay 20-60 eggs per spring after mating, mainly in the cracks of the bark. The eggs are oval in shape and have an incubation period of about 20-30 days.
Moreover, according to the research, temperature is a key environmental factor affecting the egg production of the Songmo longhorn beetle.
In a certain temperature range, the egg production of Songmo longhorn beetle increased exponentially as the temperature increased. For every 1°C increase in temperature, the rate of increase in spawning can reach 137%。This has to do with the role of temperature in promoting their metabolism.
By simulating the changes in the amount of eggs laid under different temperature conditions, the researchers concluded that the suitable temperature range for laying eggs was about 20 28°C. When the temperature is below 20°C, the spawning begins to decrease; When above 28°C, the spawn tends to decrease.
In addition, the average daily temperature also determines the peak spawning period, and the temperature factors that affect the spawning of the Songmo longhorn beetle should be subject to the average daily temperature. When the average daily temperature continues to be within the appropriate temperature range, the spawning period of Songmo longhorn beetle reaches its peak. This stage of control is particularly critical for population control.
Combined with the living habits of the Songmo longhorn beetle, its peak spawning period mainly occurs at the turn of spring and summer, and the corresponding temperature range can be subdivided into:
1.*20 22°C, suitable for early spawning**
From March to April, the average daily temperature reaches about 20°C, which is the minimum temperature limit for the adult eggs of the Songmo longhorn beetle, and the eggs are just beginning to be laid at this time. Prevention and control should be carried out at this stage.
2.*23 25°C, spawning peaks**
From May to June, the average daily temperature can reach 23 to 25 °C, which is the peak spawning period of Songmo longhorn beetle. At this time, the spawning is huge, and prevention and control must be strengthened.
3.*26 28°C, end of peak spawning**
In the summer, when the temperature exceeds 26°C, the egg production of the pine beetle will gradually decrease. When the temperature is close to 28°C, the spawning period is basically over.
According to the above laws, we can get some control measures including:
1.Focus on prevention and control in the alternating spring and summer periods, especially from May to June.
2.Adopt physical control measures, such as reducing daylight, and keeping the forest shade.
3.Apply biopesticides and choose insecticides with high efficiency and low toxicity.
4.Strengthen inspection and monitoring, and deal with adult worms in a timely manner.
Through the study of the temperature ecology of the egg-laying of the longhorn beetle, the optimal temperature range for egg-laying and the corresponding control measures were summarized, which could effectively control the population of the longhorn beetle and reduce its harm to the forest, which has important application value.