Laboratory studies on the biology and host range of Dichrorampha odorata (Lepidoptera: Tortricidae), a biological control agent for Chromolaena odorata (Asteraceae)

Abstract

a la evaluación del uso potencial de insectos como control biológico de C. bonariensis.

Do thermal requirements of Dichrorampha odorata, a shoot-boring moth for the biological control of Chromolaena odorata, explain its failure to establish in South Africa?

“…Several insect species within this niche were considered (Zachariades et al 2011), including a stem-tip boring moth discovered in Jamaica and Cuba, Dichrorampha odorata Brown and Zachariades (Lepidoptera: Tortricidae) (Strathie and Zachariades 2004). A culture of this moth was collected in Jamaica in 2005, proved easy to rear under quarantine conditions, and was both host specific and damaging (Dube et al 2017.…”

“…Dichrorampha odorata adults lay flimsy, scale-like eggs, stuck singly on the upper surface of young, fully-expanded C. odorata leaves (Dube et al 2017(Dube et al , 2019Nqayi 2019). Once the larvae hatch, they navigate to a nearby shoot tip and bore into it, killing the meristematic tissue.…”

“…Once the larvae hatch, they navigate to a nearby shoot tip and bore into it, killing the meristematic tissue. The larva causes the terminal 2-3 cm of the stem tip to swell slightly as it bores down (Dube et al 2017). The mature larva exits the stem tip and pupates inside a leaf roll on a nearby leaf (Brown and Zachariades, 2007;Dube et al 2017).…”

“…The larva causes the terminal 2-3 cm of the stem tip to swell slightly as it bores down (Dube et al 2017). The mature larva exits the stem tip and pupates inside a leaf roll on a nearby leaf (Brown and Zachariades, 2007;Dube et al 2017). The first releases of D. odorata in South Africa were made in 2013, and several thousand individual moths were subsequently released (mainly as pupae placed in a container hung on a tree branch) in KZN, Mpumalanga and Limpopo provinces, but the insect has not established (Zachariades et al 2019).…”

Differential patterns of nitrogen nutrition and growth cost of the indigenous Vachellia sieberiana and the introduced Chromolaena odorata in the savannah environment

“…However, the presence of other species with similar nutritious requirements like might promote changes in the legume preferences for N, inducing sifts from BNF to the use of soil N. Chromolaena odorata has invaded the natural ecosystems of V. sieberiana , most likely due to its ability to efficiently use the same nutrients as V. sieberiana (Mgobozi et al 2008). The displacement of native legumes by invasive plants could be explained by the invasive species’ high growth capacity, enhanced nutrient acquisition rates and resource allocation, which includes P, particularly when available at low concentrations (Dube et al 2017). In South Africa, C. odorata is a noxious weed with negative impacts on agricultural lands, grasslands, savannahs and forests (Goodall and Erasmus 1996).…”