出版社:Institute of Biological Sciences, Rajshahi University
摘要:Many hemipteran insects are phytosuccivorous in nature and predominantly feed on phloem sap, xylem sap or mesophyll cell (Novotny and Wilson 1997, Douglas 2006). Indian lac insects, Kerria lacca (Kerr) (Hemiptera: Coccoidea: Tachardiidae (=Kerriidae)) feed on sugar-rich phloem sap (Ahmad et al. 2012) – a chief source of carbon and nitrogen – and excrete excess sugar in the form of honey dew from anal tuberacle which becomes a major cause of fungal contamination. Sugar-rich honey dew attracts ants to feed upon them and thus, this ant-hemipteran mutualistic interaction prevents losses by fungus infection (Sharma and Jaiswal 2011). According to Lu et al. (2012), the presence of lac plantation with lac hosting affects the diversity and abundance of ground dwelling ant species. Among the various ant species which attend lac insects, most are harmless to lac culture, this may be due to the feeding deterrence exhibited by the anthraquinoine pigments found as body colouration of these insects. Wild type insect are crimson in colour due to the presence of a complex of closely resembling water-soluble polyhydroxy-anthraquinones (laccaic acid A, B, C, D and E), collectively called as lac dye. Yellow mutants possess only the precursor molecule laccaic acid D (Shamim et al. 2016a). Apart from these, certain alcohol-soluble anthraquinones such as desoxyerythrolaccin, erythrolaccin and isoerythrolaccin are also found in the resinous secretion of lac insects, giving it yellowish colouration (Fig. 1).