The Effect of UV-C Rays and An Insect Growth Regulator on the Growth and Development of Potato Tuber Moth Phthorimaea operculella

Abstract

The study aimed to control the potato tuber moth Phthorimaea operculella (Zeller) by using
Insect Growth Regulator (Match) and UV-C with a wavelength of 254 nm on adults and
incomplete stages (eggs and larvae). The results indicated that (1-2) days old eggs treated by
UV-C rays with different exposure times (4,8,12 and 16 min.), from a distance of 50 cm and
insect growth regulator had almost the same effect on the eggs' hatching rates. The highest nonhatching
rates of eggs that sprayed by insect growth regulator was 59.30% at a concentration
of 2 ml /L. While the highest non-hatched rates of eggs that exposed to UV-C rays was 62.20%
at a 16-minute exposure period. The results also showed that of (1-2) day old eggs treated with
ultraviolet rays or treated with the insect growth regulator (Match) were more vulnerable than
eggs at (5-6) days old. As the proportionality was direct between the rates of eggs non-hatching
and the duration of exposure to radiation or the concentration of the insect growth regulator.
The results showed that the first instar larvae were more affected than the fourth instar larvae
by both insect growth regulator and UV-C treatments, at different concentrations and exposure
times. The highest mortality rates for first-stage larvae under the influence of growth regulator
were 42.20% at a concentration of 2 ml/L and 52.20% under the influence of UV-C rays,
exposure time of 16 min., compared with 5.33 and 8.33% in the control treatment, respectively.
As for the effect of ultraviolet radiation on the adults of the potato tuber moth, the difference in
fertility results (number of laid eggs / female) decreased dramatically, as the number of eggs
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Academic Science Journal
P-ISSN: 4612-2958
Volume: 19, Issue: 2
Manuscript Code: 675A
laid in the control treatment was 113.00 eggs / female. The lowest number of eggs laid was
23.55 eggs / female when insects were exposed to UV rays for 16 min., while the percentages
of hatching, pupation and emergence were 76.33, 68.30 and 60.30% in the control treatment,
and decreased to 22.30, 18.10 and 8.00% respectively, when insect exposed to UV-C rays for
16 minutes. The results indicate the possibility of using UV-C rays and the insect growth
regulator (Match) of chemical pesticides to control potato tuber moth.