Bionomics of Hypolıxus truncatulus (F.) (Coleoptera: Curculionidae: Lixinae: Lixini), a major pest of Amaranthus caudatus L.

Abstract :

Hypolixus truncatulus (F.) has been observed as a major pest of cultivated amaranthus viz., Amaranthus caudatus L. in the Jammu region whose leaves are used as greens and seeds for medicinal purposes. Maximum of 49 specimens at different stages of development were recorded (±SE) from a single plant. Weevils were found to breed from April to November and overwinter in soil or inside the debris of harvested plants. Adults defoliate the plants while larvae feed on internal tissues of the stem and branches to form irregular zigzag tunnels resulting in galls. Infestation varies from 34.96 to 82.3% with an average of 62.52% ±21.4. Mating normally lasts for one and half an hour. Female after 20-40 minutes of copulation commences laying eggs singly in the excavated hole in the stem, branches, petiole or midrib of the leaves. Incubation varies between 3-6 days with an average of 4.2±0.36 days. Larva when taken out of the stem or branch shows a typical C-shaped curvature. Larval period ranges from 42-45 days with an average of 43.6±0.45 days. Pupal period ranges from 12-15 days with an average of 13.5±0.43 days. Total life cycle takes 58-64 days with a mean of 61.10±0.71 days. At least three overlapping generations were observed from April to November

Keyword :

Hypolixus truncatulus, bionomics, Amaranthus caudatus, infestation

Author(s) : Tara, J. S., Azam, M., Ayri, S., Feroz, M., Ramamurthy, V. V.
Downloads : 2692
Published Issue : 2009 Vol. 4 Number 2

2009 Vol. 4 Number 2