Effects of four host plants on biology and food utilization - Journal of ...
Effects of four host plants on biology and food utilization - Journal of ...
Effects of four host plants on biology and food utilization - Journal of ...
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<strong>Journal</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> Insect Science: Vol. 10 | Article 22<br />
Introducti<strong>on</strong><br />
Spodoptera litura (Fabricius) (Lepidoptera:<br />
Noctuidae) is polyphytophagous, damaging<br />
numerous vegetables <strong>and</strong> field crops in China<br />
<strong>and</strong> many other Asian countries (Shu 1959;<br />
Hill 1975; Shivayogeshwara 1991). S. litura is<br />
also known as the comm<strong>on</strong> or tobacco<br />
cutworm, or the cluster or tobacco caterpillar.<br />
Although it had been a sporadic pest <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
tobacco in northern China for many years, it<br />
has been becoming gradually a very important<br />
insect pest in recent years (Guan <strong>and</strong> Chen<br />
1999; Gao et al. 2004; Qin et al. 2004). It also<br />
becomes resistant to many comm<strong>on</strong>ly used<br />
insecticides, particularly pyrethroids <strong>and</strong><br />
carbamates, resulting in failure <str<strong>on</strong>g>of</str<strong>on</strong>g> effective<br />
c<strong>on</strong>trols (Wu et al. 1995; Kranthi et al. 2002;<br />
Ahmad et al. 2007; Huang <strong>and</strong> Han 2007).<br />
Study <str<strong>on</strong>g>of</str<strong>on</strong>g> the effects <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>host</str<strong>on</strong>g> <str<strong>on</strong>g>plants</str<strong>on</strong>g> <strong>on</strong> the<br />
<strong>biology</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> insects is important in<br />
underst<strong>and</strong>ing <str<strong>on</strong>g>host</str<strong>on</strong>g> suitability <str<strong>on</strong>g>of</str<strong>on</strong>g> plantinfesting<br />
insect species. There have been a<br />
number <str<strong>on</strong>g>of</str<strong>on</strong>g> studies <strong>on</strong> the biological<br />
parameters <str<strong>on</strong>g>of</str<strong>on</strong>g> S. litura <strong>on</strong> different <str<strong>on</strong>g>host</str<strong>on</strong>g> <str<strong>on</strong>g>plants</str<strong>on</strong>g><br />
under different envir<strong>on</strong>mental c<strong>on</strong>diti<strong>on</strong>s,<br />
particularly in India (Patel et al. 1986, 1987),<br />
Pakistan (Ahmad et al. 2007), China (Guan<br />
<strong>and</strong> Chen 1999; Zhu et al. 2000; Qin et al.<br />
2004; Zhu et al. 2005), Korea (Bae et al.<br />
1997; Bae 1999a,b; Bae <strong>and</strong> Park 1999), <strong>and</strong><br />
other Asian countries (Etman <strong>and</strong> Hooper<br />
1979; Holloway 1989) where S. litura has<br />
been an important pest <strong>on</strong> various crops.<br />
However, not all <str<strong>on</strong>g>of</str<strong>on</strong>g> these studied the effects <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
the same <str<strong>on</strong>g>host</str<strong>on</strong>g> <str<strong>on</strong>g>plants</str<strong>on</strong>g> <strong>on</strong> development,<br />
survival, pupal weight <strong>and</strong> ovipositi<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> S.<br />
litura under the same envir<strong>on</strong>mental<br />
c<strong>on</strong>diti<strong>on</strong>s, <strong>and</strong> n<strong>on</strong>e studied the adaptati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
S. litura <strong>on</strong> tobacco for two generati<strong>on</strong>s after<br />
they were reared <strong>on</strong> an artificial diet.<br />
Thus, the objectives <str<strong>on</strong>g>of</str<strong>on</strong>g> this study were to<br />
determine (a) ovipositi<strong>on</strong> preference by the<br />
females <strong>and</strong> the development <strong>and</strong> survival <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
larval <strong>and</strong> pupal stages <str<strong>on</strong>g>of</str<strong>on</strong>g> S. litura <strong>on</strong> tobacco,<br />
Chinese cabbage, cowpea <strong>and</strong> sweet potato<br />
<strong>and</strong> (b) <strong>food</strong> utilizati<strong>on</strong> <strong>on</strong> the <str<strong>on</strong>g>four</str<strong>on</strong>g> <str<strong>on</strong>g>host</str<strong>on</strong>g> <str<strong>on</strong>g>plants</str<strong>on</strong>g>.<br />
Materials <strong>and</strong> Methods<br />
Host <str<strong>on</strong>g>plants</str<strong>on</strong>g><br />
Four <str<strong>on</strong>g>host</str<strong>on</strong>g> <str<strong>on</strong>g>plants</str<strong>on</strong>g> were used in this study,<br />
including tobacco (Nicotiana tabacum L.,<br />
variety ‘NC89’), Chinese cabbage (Brassica<br />
rapa var. chinensis, variety ‘Sh<strong>and</strong><strong>on</strong>g Fushen<br />
Baotou’), cowpea (Vigna sinensis L. Walp.<br />
ssp. uniguiculata, variety ‘Zhijiang 28-2’),<br />
<strong>and</strong> sweet potato (Ipomoea batatas L., variety<br />
‘Yushu 10’). These <str<strong>on</strong>g>plants</str<strong>on</strong>g> were selected<br />
because they are the most important ec<strong>on</strong>omic<br />
crops in northern China <strong>and</strong> are primary <str<strong>on</strong>g>host</str<strong>on</strong>g><br />
<str<strong>on</strong>g>plants</str<strong>on</strong>g> <str<strong>on</strong>g>of</str<strong>on</strong>g> S. litura.<br />
The <str<strong>on</strong>g>four</str<strong>on</strong>g> species <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>host</str<strong>on</strong>g> <str<strong>on</strong>g>plants</str<strong>on</strong>g> were singly<br />
planted in plastic pots (19-cm in diameter <strong>and</strong><br />
14 cm in depth) in a greenhouse at Sh<strong>and</strong><strong>on</strong>g<br />
Agricultural University at Taian, Sh<strong>and</strong><strong>on</strong>g,<br />
China, <strong>and</strong> were maintained insecticide-free.<br />
The <str<strong>on</strong>g>plants</str<strong>on</strong>g> were used when they had 4-5 true<br />
leaves.<br />
Insects<br />
S. litura larvae were originally collected from<br />
cabbage fields (Brassica oleracea var.<br />
capitata L.), <strong>and</strong> were subsequently reared <strong>on</strong><br />
an artificial diet at the Institute <str<strong>on</strong>g>of</str<strong>on</strong>g> Pomology,<br />
Guangd<strong>on</strong>g Academy <str<strong>on</strong>g>of</str<strong>on</strong>g> Agricultural Science,<br />
Guangzhou, Guangd<strong>on</strong>g. The artificial diet<br />
c<strong>on</strong>tained the following ingredients: 137 g <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
corn flour, 10 g <str<strong>on</strong>g>of</str<strong>on</strong>g> yeast, 37.5 g <str<strong>on</strong>g>of</str<strong>on</strong>g> soybean<br />
flour, 3.5 g <str<strong>on</strong>g>of</str<strong>on</strong>g> multiple vitamins, 1 g <str<strong>on</strong>g>of</str<strong>on</strong>g> sorbic<br />
acid, 2 g <str<strong>on</strong>g>of</str<strong>on</strong>g> nipagin, 12.5 g <str<strong>on</strong>g>of</str<strong>on</strong>g> agar, 0.16 g <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
inositol, <strong>and</strong> 0.15 g cholesterol. Soybean flour<br />
<strong>and</strong> corn flour were sterilized for 40 min<br />
Xue et al.<br />
<strong>Journal</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> Insect Science | www.insectscience.org 2