Seasonal activity of the guava long scale insect Lepidosaphes tapleyi (Hemiptera : Diaspidiae)‎ infesting guava trees in Luxor governorate, Egypt

الملخص EN

The present work was carried out throughout two successive years (2017/2018 and 2018/2019) at Esna district, Luxor Governorate.

As a basic study for developing future management of the guava long scale insect, Lepidosaphes tapleyi (Williams) (Hemiptera: Diaspidiae), to determine the seasonal activity of this insect.

In this investigation, two insect expressions were utilized, i.e., Insect numbers and incidence of infestation, which articulated the population density of this pest.

The obtained results showed that insect population of L.

tapleyi occurred on guava trees all the year round and has four to five peaks of seasonal activity per year, which was recorded on the beginning of April, mid-May, mid-July, beginning of October and mid-November during the first year (2017/2018) and through the mid-April, mid-July, mid-September and beginning of November during the second year (2018/2019).

Furthermore, the percentages of infestation incidence by pests showed, also, have four to five peaks per year.

Also, the total population density by L.

taplyi was higher through the second year in compared to the first year of study, which may be due to the influence of favorable factors (such as environmental conditions….

etc.).

It seems that, the climatic conditions of autumn and summer months during the two years were more suitable for the population density and its activity and the maximum values of the infestation incidence by L.

taplyi.

As well, it was generally found that autumn season was more favorable for the insect multiplication and build up, than the remaining three seasons in each year during the two years.

The obtained results showed that, the effect of weather factors (mean daily of air temperature, mean of relative humidity and mean of dew point) on the insect population and on the percentages of infestation incidence by L.

taplyi were, highly significant during the two successive years, and these factors varied from year to another.

Also, the dew point was the most effective variable for the changes in the insect population and the percentages of infestation incidence under the studied years.