SUITABILITY OF THE NORTH-AMERICAN WEEDS SESBANIA-EXALTATA AND S-DRUMMONDII (LEGUMINOSAE) AS HOSTS FOR NEODIPLOGRAMMUS-QUADRIVITTATUS AND TRICHAPION-LATIVENTRE (COLEOPTERA, CURCULIONIDAE) IN ARGENTINA
Ga. Logarzo et Ma. Casalinuovo, SUITABILITY OF THE NORTH-AMERICAN WEEDS SESBANIA-EXALTATA AND S-DRUMMONDII (LEGUMINOSAE) AS HOSTS FOR NEODIPLOGRAMMUS-QUADRIVITTATUS AND TRICHAPION-LATIVENTRE (COLEOPTERA, CURCULIONIDAE) IN ARGENTINA, Environmental entomology, 26(2), 1997, pp. 343-348
Neodiplogrammus quadrivittatus (Oliver) and Trichapion lativentre (beg
uin-Billecocq) are 2 South American weevils successfully used for the
biological control of Sesbania punicea (Cavanille) Benth. in South Afr
ica. The potential of these insects as control agents for the weeds Se
sbania exaltata (Raf.) Rydb. and S. drummondii (Rydb.) Cory in the Uni
ted States was studied in Argentina. Estimation of adult consumption,
the food preference of adult insects on 5 species of Sesbania (3 nativ
e hosts and the 2 weeds mentioned above), the capacity of the insects
to complete their life cycle on the weeds, and the weed infestation by
wild populations in the laboratory garden were studied. The consumpti
on of N. quadrivittatus on both north American weeds did not differ fr
om that on native hosts. Similar consumption was observed for T. lativ
entre feeding on S. drummondii. S. exaltata showed the lowest consumpt
ion. The feeding preference of N. quadrivittatus was similar to that o
f its natural host plants. In the case of T. lativentre, results on on
ly S. drummondii were comparable to that of its natural hosts. Both in
sects were able to complete their life cycles on the weeds. In the gar
den, there was a marked preference by the weevils for S. drummondii. S
. exaltata was not attacked by T. lativentre and no test was carried o
ut with N. quadrivittatus. We concluded that both insects are good bio
control candidates for S. drummondii, whereas only N. quadrivittatus i
s a promising control agent for S. exaltata.