The parasitoid Praon volucre (Hymenoptera: Braconidae: Aphidiinae) as a potential biological control agent of the aphid Uroleucon ambrosiae (Hemiptera: Aphididae) on lettuce in Brazil

Abstract

Abstract. The aphid Uroleucon ambrosiae (Thomas) is one of the principal pests found on greenhouse lettuce crops, and there is no efficient biological control agent of this pest in Brazil. This work evaluates the aphid U. ambrosiae as a host for the parasitoid Praon volucre (Haliday), aimed at using P. volucre as a potential biological control agent of U. ambrosiae on lettuce. As Macrosiphum euphorbiae (Thomas) is a common host of P. volucre in the field, the development of the parasitoid was compared on these two aphid species. Twenty nymphs of the 2 nd instar were kept with P. volucre for one hour at 22 ± 1°C, 70 ± 10% RH and a 12 h photophase. The size of the aphid's tibiae at the moment of oviposition indicated that there was no significant size difference between U. ambrosiae (0.6 ± 0.02 mm) and M. euphorbiae (0.7 ± 0.03 mm). When mummies were formed, M. euphorbiae had significantly longer tibia (1.5 ± 0.03 mm) than U. ambrosiae (1.4 ± 0.02 mm). No significant differences were detected in the percentage emergence (74.9 ± 7.92 and 87.5% ± 3.31 for U. ambrosiae and M. euphorbiae, respectively), or proportion of female offspring (56.2 ± 7.62 and 44.2 ± 7.14%). The development time from oviposition to adult and longevity of females and males of P. volucre reared on the two host species were not different. High parasitism levels were recorded for both host aphid species, but the percentage parasitism of M. euphorbiae (54.4 ± 4.40) was higher than of U. ambrosiae (35.6 ± 5.30). Female parasitoids reared on M. euphorbiae had longer tibiae (0.78 ± 0.01 mm) than those reared on U. ambrosiae (0.72 ± 0.01 mm). Our results demonstrate that the alternative host species U. ambrosiae, compared to the natural host species M. euphorbiae, affects the female's size, but did not affect parasitoid development time, longevity, emergence or sex ratio. The parasitoid P. volucre seems to be a good candidate for using as a biological control agent of U. ambrosiae on lettuce in Brazil.

Praon volucre (Hymenoptera: Braconidae: Aphidiinae), a natural enemy of Macrosiphum euphorbiae (Hemiptera: Aphididae): Life table and intrinsic rate of population increase

“…In the absence of hosts, P. volucre females live for 14.1 days (Silva et al, 2009) and of 20.4 days (De Conti et al, 2008). In this study a shorter longevity of 11 days in the presence of hosts was recorded and this is thought to be due to the costs of egg laying (Roitberg et al, 2001).…”

“…These authors also report high rates of parasitism of the aphids M. euphorbiae, Uroleucon ambrosiae (Thomas) and Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae) by P. volucre (De Conti et al, 2008;Silva et al, 2009). Currently, the commercially available parasitoid for M. euphorbiae control is A. ervi and as there are many cases of the control of this aphid by this parasitoid being insufficient there is certainly a need for a more efficient natural enemy (J. van Schelt, 2010, pers.…”

Identification of molecular markers for DNA barcoding in the Aphidiinae (Hym. Braconidae)

“…Aphidiinae (Braconidae) are tiny wasps that exclusively develop as aphid (Hemiptera) endoparasitoids. Because the host is killed at the end of parasitoid larval development, some aphidiine species are used as biological control agents of aphids (e.g Hawkins & Cornell 1994; De Conti et al. 2008).…”

Larval Competition BetweenAphidius erviandPraon volucre(Hymenoptera: Braconidae: Aphidiinae) inMacrosiphum euphorbiae(Hemiptera: Aphididae)

“…The effectiveness of such parasitoids as pest control agents has been demonstrated by various studies (Sampaio et al 2006De Conti et al 2008;Silva et al 2008). Twelve species of aphid parasitoids were introduced into Brazil in the 1980s for biological control of several aphids on wheat crops, among which were the endoparasitoids Aphidius ervi (Haliday) and Praon volucre (Haliday) (Gassen and Tambasco 1983).…”