Abstract

MENDEZ-GALLEGOS, S. de Jesús et al. Growth parameters of cochineal Dactylopius coccus Costa reared in five cactus pear cultivars Opuntia ficus-indica Mill. Agrociencia [online]. 2010, vol.44, n.2, pp.225-234. ISSN 2521-9766.

Cochineal (Dactylopius coccus Costa) is considered one of the main sources of natural coloring worldwide; therefore, it has been introduced into several countries for commercial exploitation. Nevertheless, insect behavior and coloring quality obtained from hosts, other than those of the natural habitat where they develop, are not known. To clarify the aforesaid, survival and reproduction of D. coccus and their quality (percentage of carminic acid) in five cactus pear cultivars (Blanco Moscatel, Colorado Moscatel, Offer, Portolano, Sicilia Bianca) of different geographic origin, were assessed. The study was carried out in breeding chambers, at 24±1 °C, 65±5% HR, and photoperiod 14:10 (Darkness:Light), using the demographic technique of life and fertility tables for obtaining the parameters that characterize D. coccus population dynamics. Cactus pear cultivars provided as nutritional substrate caused differential effect on survival, reproduction, and carminic acid. The highest values of intrinsic rate of increase (r_m) were achieved in the cohorts developed in the cultivars: Offer, Portolano, and Sicilia Bianca, with 0.025, 0.021, and 0.003 females d^-1. The D. coccus populations reared in cultivars Colorado Moscatel and Blanco Moscatel did not have progeny. However, in the latter cultivar, the highest percentage of carminic acid was obtained (19.1 %). In this study, it was possible to differentiate cultivars which could be used as substrate for generating breeding stock or for carminic acid production, or serving both purposes.

Keywords : carminic acid; cochineal; reproduction; survival; life tables.