Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Melanism and disease resistance in insects.
AU - Wilson, Kenneth
AU - Cotter, Sheena C.
AU - Reeson, Andrew F.
AU - Pell, Judith K.
PY - 2001/11
Y1 - 2001/11
N2 - There is growing evidence that insects in high-density populations invest relatively more in pathogen resistance than those in low-density populations (i.e. density-dependent prophylaxis). Such increases in resistance are often accompanied by cuticular melanism, which is characteristic of the high-density form of many phase polyphenic insects. Both melanism and pathogen resistance involve the prophenoloxidase enzyme system. In this paper the link between resistance, melanism and phenoloxidase activity is examined in Spodoptera larvae. In S. exempta, cuticular melanism was positively correlated with phenoloxidase activity in the cuticle, haemolymph and midgut. Melanic S. exempta larvae were found to melanize a greater proportion of eggs of the ectoparasitoid Euplectrus laphygmae than non-melanic larvae, and melanic S. littoralis were more resistant to the entomopathogenic fungus Beauveria bassiana (in S. exempta the association between melanism and fungal resistance was non-signficant). These results strengthen the link between melanism and disease resistance and implicate the involvement of phenoloxidase.
AB - There is growing evidence that insects in high-density populations invest relatively more in pathogen resistance than those in low-density populations (i.e. density-dependent prophylaxis). Such increases in resistance are often accompanied by cuticular melanism, which is characteristic of the high-density form of many phase polyphenic insects. Both melanism and pathogen resistance involve the prophenoloxidase enzyme system. In this paper the link between resistance, melanism and phenoloxidase activity is examined in Spodoptera larvae. In S. exempta, cuticular melanism was positively correlated with phenoloxidase activity in the cuticle, haemolymph and midgut. Melanic S. exempta larvae were found to melanize a greater proportion of eggs of the ectoparasitoid Euplectrus laphygmae than non-melanic larvae, and melanic S. littoralis were more resistant to the entomopathogenic fungus Beauveria bassiana (in S. exempta the association between melanism and fungal resistance was non-signficant). These results strengthen the link between melanism and disease resistance and implicate the involvement of phenoloxidase.
U2 - 10.1046/j.1461-0248.2001.00279.x
DO - 10.1046/j.1461-0248.2001.00279.x
M3 - Journal article
VL - 4
SP - 637
EP - 649
JO - Ecology Letters
JF - Ecology Letters
SN - 1461-023X
IS - 6
ER -