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 usingInsect Growth Regulator (Match) and UV-C with a wavelength of 254 nm on adults andincomplete stages (eggs and larvae). The results indicated that (1-2) days old eggs treated byUV-C rays with different exposure times (4,8,12 and 16 min.), from a distance of 50 cm andinsect growth regulator had almost the same effect on the eggs' hatching rates. The highest nonhatchingrates of eggs that sprayed by insect growth regulator was 59.30% at a concentrationof 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 withultraviolet rays or treated with the insect growth regulator (Match) were more vulnerable thaneggs at (5-6) days old. As the proportionality was direct between the rates of eggs non-hatchingand 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 larvaeby both insect growth regulator and UV-C treatments, at different concentrations and exposuretimes. The highest mortality rates for first-stage larvae under the influence of growth regulatorwere 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 infertility results (number of laid eggs / female) decreased dramatically, as the number of eggs208Academic Science JournalP-ISSN: 4612-2958Volume: 19, Issue: 2Manuscript Code: 675Alaid in the control treatment was 113.00 eggs / female. The lowest number of eggs laid was23.55 eggs / female when insects were exposed to UV rays for 16 min., while the percentagesof 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 for16 minutes. The results indicate the possibility of using UV-C rays and the insect growthregulator (Match) of chemical pesticides to control potato tuber moth.