The development of Liriomyza sativae
The developmental time of
L. sativae was significant affected by host plants. The leafminers feeding on kidney bean plants developed more rapidly than those reared on pak choi (Table 1). The duration of egg and larval stages was non significant difference with kidney bean and pak choi. The pupal stage was longer on pak choi than that on kidney bean. The total developmental time from egg to adult emergence of the vegetable leafminer fed on kidney bean was significantly shorter (17.1 days) than that on pak choi (18.2 days) (Table 1). The results were in agreement with the results of
(Aroujo et al., 2013; Haghani et al., 2007). Aroyjo et al., (2013) who reported different development period of
L. satiave on different host plants.
Aroyjo et al., (2013) reported that the developmental time from egg to adult emergence of
L. sativae reared on melon (
Cucumis melon L.) at 25
oC lasted 15.9 days. However,
Haghani et al., (2007) indicated that the total development of
L. sativae feeding on cucumber plants (
Cucumis sativus L.) at 25
oC was 20.6 days. Since differences in some biological characteristics between different biotypes of an insect (e.g. whitefly)
(Yao et al., 2017) are considered to affect the outcome of their competition, further research on biotypes and its host preference of
L. sativae could be considered.
The longevity and fecundity of Liriomyza sativae
There were no significant differences between the mean longevities of
L. sativae adults feeding on different host plants (Table 2). The longevities of the female were 10.5 and 9.3 days on kidney bean and pak choi, respectively. The longevities of the vegetable leafminer male were 3.3 and 2.9 days on kidney bean and pack choi, respectively. The longevities of males and females observed in this study differed from other studies on
L. sativae with longer longevity than those observed in cowpea plants [
Vigna unguiculata (L.) Walp]
(Costa-Lima et al., 2010).
The damage caused by
L. sativae to plants is very similar to other
Liriomyza species: larvae mine and feed within the leaves and females produce feeding punctures on the leaves with their ovipositor. The adults feed from all punctures, regardless of whether or not they are used for oviposition (
Parrella, 1987). The feeding activity of a female on kidney bean (2062.5 punctures) was significant higher than that on pak choi (842.5 punctures) (Table 2). Leaf punctures can reduce photosynthesis and may kill young plants. Therefore, leaf puncturing and feeding by adult
Liriomyza undoubtedly serve an important role in host plant loss assessment (
Parrella, 1987).
In this study, host plants have a significant effect on
L. sativae reproduction parameters. On pak choi, the
L. sativae females took 2.0 days to begin oviposition, whereas it was only 1.2 days on kidney bean. However, there was not significant difference in the vegetable leafminer’s post-oviposition period. The vegetable leafminers that fed on kidney bean had higher fecundity. The fecundity was 190.2 and 73.3 eggs on kidney bean and pak choi, respectively (Table 2). A high fecundity of
L. sativae on cowbean have been also reported by
Costa-Lima et al., (2010).
Previous studies indicated that different host plants played an important role on the development, survival rate, longevity and fecundity of insect pests
(Bertin et al., 2013; Tran and Nguyen, 2019).
Awmack and Leather (2002) stated that host plant quality and its components like secondary metabolites, nitrogen and carbon is known as key determinant, which directly affects the development, fecundity and reproductive strategies of insect.
Zhao and Khang (2002) indicated the odour of kidney bean,
P. vulgaris attracts both males and females of
L. sativae, this in turn the host preference of
L. sativae to kidney bean followed by pak choi.
