Effect of different fertilizer treatments on the life history of vegetable leafminer, Liriomyza sativae Blanchard, on cucumber

Vegetable leafminer, Liriomyza sativae Blanchard, is one of the most important pests of cucumber, especially in greenhouses. In this study, effect of different fertilizer treatments, including vermicompost, humic acid, nitrogen, vermicompost-humic acid and vermicompost-humic acid-nitrogen mixture, were investigated on biological parameters of vegetable leafminer along with some growth indices of cucumber plant including plant height and chlorophyll content. The experiments were carried out in a growth chamber at 25 ± 2˚C, relative humidity of 65 ± 5 %, and a photoperiod of 16 L: 8 D. Based on the results, the duration of immature stages and longevity of adults were significantly different on the tested treatments. Duration of immature stages was highest on humic acid treatment (3.36 d) and lowest on control (3.13 ± 0.06). Furthermore, the lowest values of longevity and life span of adults were recorded on humic acid (6.57 and 27.21 d, respectively) and the highest values of these parameters were on nitrogen treatment (11.14 and 30.11 d, respectively). The tested treatments had significant effects on population growth parameters of the pest. The highest values of intrinsic rate of natural increase (r) and net reproductive rate (R0) of the vegetable leafminer were on nitrogen treatment (0.1640 d-1 and 52.70 offspring/female, respectively) and the lowest values of these parameters were on humic acid treatment (0.0888 d-1 and 9.67 offspring/female, respectively). The results of the present study showed that humic acid can be used in integrated management of the vegetable leafminer in cucumber growing area.