Research On The Population Control Of Adult Liposcelis Bostrychophilus In The Grain Bulks By Different Mechanical Ventilation Modes

Mechanical ventilation of grain storage is widely used as a main technical means to reduce temperature and humidity,controlling the moisture conten of grain.Mechanical ventilation will change the ecological environment in the grain bulks and affect the development of pests.However,mechanical ventilation as a method to control the number of pests in grain bulks,it is still a blank field.In this paper,I studied the important pest of Liposcelis bostrychophilus.Using mechanical ventilation technology make the grain bulks ecosystem is under the state of artificial regulation.Destroyed the suitable growth environment to control the the number of Liposcelis bostrychophilus.Then,build a stable grain bulks ecosystem that is conducive to the safe and stable of storage grain.The effects of mechanical ventilation inner the grain bulks ecosystem on the survival of the Liposcelis bostrychophilus were researched by different mechanical ventilation methods(upward vertical ventilation,upward circulation ventilation),different ventilation rate of per unit area and the change of temperature and humidity.It provides theoretical basis and data support for mechanical ventilation in the prevention and control of Liposceilis bostrychophilus.To provide theoretical basis and data support for control the number of Liposcelis bostrychophilus by mechanical ventilation.To provide research method for control the number of other grain pests.1 This study monitored the number of Liposcelis in warehouse,where is the middle-temperature and high-humidity grain storage area,middle-temperature and low-humidity grain storage area,low-temperature and high-humidity grain storage area and low-temperature and low-humidity grain storage area.In the middle-temperature and high-humidity grain storage area,the density of Liposcelis was 1.7×104~3.8×105 worm/m2.After the fumigation,theLiposcelis still has a larger pests density(more than 250 worm/m2).In the middle-temperature and low-humidity grain storage area,the density of Liposcelis was 1000~12.5 ×104 worm/m2.The population of Liposcelis varies regularly according to seasons.In the low-temperature and high-humidity grain storage area and low-temperature and low-humidity grain storage area,the density of Liposcelis was lower than 50 worm/m2.In these areas can achieve(quasi)low temperature storage throughout the year.The Liposcelis is difficult to survive and reproduction in these areas.2.In order to explore the regularities of mechanical ventilation in the control of the Liposcelis in the grain bulks,a small-scale warehouse was designed and made.The small-scale warehouse is an acrylic material silo with the height of 110cm,the outer diameter of 50cm and the thickness of 1 cm.The small-scale warehouse not only simulation the ecological environment of the Liposcelis multiplied wildly area within the grain bulks,but also realizes the application of mechanical ventilation in different methods.3.This study found that vertical ventilation and circulation ventilation have a clear ecological control effect on the adults of the Liposcelis bostrychophilus in the grain bulks.With the increase of ventilation time,the mortality rate of the Liposcelis bostrychophilus in the grain bulks increased gradually,and eventually reached 100%.It is feasible to use mechanical ventilation to control the population of the Liposcelis bostrychophilus in grain bulks.4.This study found that using vertical ventilation of the ventilation rate of per unit area are 0.033m/s,0.048m/s and 0.062m/s,respectively,to control the population of Liposcelis bostrychophilus,and the time required for mortality was 90%are 97.2h?73.1h.80.5h.The logistic equation between ventilation time and the mortality rate of the Liposcelis bostrychophilus are as follows:m=1/-0.0556 + 0.1014 x 0.9957t m=1/0.0077 + 0.9759 ×0.9322tm=1/0.0083 +0.0098 ×0.8782t5?This study found that using circulation ventilation of the ventilation rate of per unit area are 0.038m/s,0.054m/s and 0.065m/s,respectively,to control the population of Liposcelis bostrychophilus?and the time required for mortality was 90%are 98.4h?89.4h?38.3h.The logistic equation between ventilation time and the mortality rate of the Liposcelis bostrychophilus are as follows:m =1/0.0021 + 00383 x 0.9854t m=1/-0.0052 + 0.0267 x 0.9945t,m=1/0.0083 +0.0168 × 0.9544t6?This study found that under the condition of same ventilation time and equipment,the control effect of circulation ventilation is slightly better than that of vertical ventilation.Comprehensive the factors such as control effect,ventilation time,and moisture loss of the grain bulks,while achieving the purpose of controlling Liposcelis,at the same time,should minimize energy consumption and reduce losses.It is recommended to use circulation ventilation with low and middle ventilation rate to control the Liposcelis.