The biology and host specificity of Pareuchaetes aurata aurata (Lepidoptera: Arctiidae), a ‘new association’ biological control agent for Chromolaena odorata (Compositae)

Abstract

Pareuchaetes aurata aurata (Butler) from Chromolaena jujuensis in northern Argentina was tested as a biological control candidate for the composite weed C. odorata. The larvae feed voraciously and complete their development on C. odorata. The host-plant feeding range of P. a. aurata is limited to the genus Chromolaena. It is suggested that the egg-laying behaviour of P. a. aurata, which scatters its eggs around the base of the host-plant, will help to overcome the problem of ant predation which prevented the establishment of Pareuchaetes pseudoinsulata Rego Barros, which lays its eggs in batches, in South Africa. Any possible benefits of the new association between P. a. aurata and C. odorata may also contribute to the success of this biological control programme.

The Life History Traits of the Arctiine MothPareuchaetes insulata, a Biological Control Agent ofChromolaena odoratain South Africa

“…Our findings indicate that over 74 % of the eggs were laid during the first four nights (after mating) with peak egg laying on the second night. This concurs with the findings of Kluge & Caldwell (1993b) who reported that 70 % of oviposition occurred within the first four nights for P. aurata aurata. This relatively short window exemplifies why protogyny could lead to matelessness.…”

“…Mean lifetime fecundity (387 ± 19.62 eggs) per female was 23 % higher than that recorded for a closely related species, P. aurata aurata, where lifetime fecundity averaged 241.9 eggs per female (Kluge & Caldwell 1993b). Our findings indicate that over 74 % of the eggs were laid during the first four nights (after mating) with peak egg laying on the second night.…”

“…Although the use of excised leaves in the determination of insect survival and performance has been a subject of debate (Olckers & Hulley 1994;Blossey & Nötzold 1995;Palmer 1999), this practice is seen as an acceptable method for providing uniform materials in laboratory feeding studies of this kind (see Blossey & Nötzold 1995;Hull-Sanders et al 2007;Beaton et al 2011;Oleiro et al 2011;Boughton & Pemberton 2012). Moreover, all other previous work (Muniappan et al 1989;Kluge & Caldwell 1993b;Dube et al 2014) on aspects of the biology of Pareuchaetes species have been conducted using excised leaves of C. odorata.…”

“…Furthermore, previous research (Kluge & Caldwell 1993a;Walton & Conlong 2003;Dube 2008) undertaken to document the biology of the moth did not consider differences between female and male traits; hence, this study addresses this lacuna because the development and growth of moths sometimes vary as a function of sex (Thiéry & Moreau 2005;. Experiments reported here were conducted to investigate several aspects of the biology of P. insulata to understand the poor performance of moth in the field and to allow comparison with earlier studies on P. pseudoinsulata (Cruttwell 1972;Muniappan et al 1989) and P. aurata aurata (Kluge & Caldwell 1993b). This study compares metrics of the moth's performance such as leaf consumption, development duration, pupal mass, growth rate and longevity between male and females which was not considered by Kluge & Caldwell (1993a) and Dube (2008).…”

“…Although the biology of P. insulata appears to be similar to that of P. pseudoinsulata (Bennett & Cruttwell 1973) and P. aurata aurata (Kluge & Caldwell 1993b), a further and comprehensive understanding of its developmental and reproductive biology is needed. Information on several aspects of the life history traits of P. insulata might assist in unravelling the reasons for the low population levels in the field and could enable us to gain a thorough knowledge of the behaviour of the erebid moth in its new environment.…”