Ha. Cordo et al., BIONOMICS OF CARMENTA-HAEMATICA (URETA) (LEPIDOPTERA, SESIIDAE) WHICHATTACKS SNAKEWEEDS (GUTIERREZIA SPP) IN ARGENTINA, Biological control, 5(1), 1995, pp. 11-24
Adult Carmenta haematica are day-flying moths with orange (female) or
clear (male) wings and a wingspan of 20 to 24 mm. Adults mated in brig
ht sunlight. Females lived an average 2.3 days and laid an average 240
eggs each on stems and twigs of the host plant. Only 66% of the eggs
hatched, mostly in the 4 h before dawn. Larvae had seven instars and r
eached ca. 24 mm long when full grown. Larvae entered the plant at the
base of twigs or leaves or sometimes directly into the crowns. They w
ere cannibalistic after the second instar and usually only one large l
arva occurred in a plant in the field. Larger larvae tunneled in the l
arger roots and made an exit hole in a large stem 5-8 cm above the cro
wn where they pupated; a silken tube often protruded from the exit hol
e. The life cycle required ca. 139.5 days at 30 degrees C: 15 days for
the egg, 107 days for the larva, 16.5 days for the pupa, and 1 day fo
r the adult to reach peak oviposition. Larval survival decreased below
0 degrees C, and all larvae died after 1 day at -15 degrees C. Larvae
pupated in midsummer, adults emerged in late summer, and larvae devel
oped during the fall, winter, and spring. The species was mostly univo
ltine, but the presence of some large larvae and pupae during most mon
ths indicated some variation. In the field, larvae infested 20 to 25%
of medium-sized or large plants. At three locations of unusually high
larval populations, the combined attack by C. haematica, other root bo
rers, and drought killed most plants of Gutierrezia solbrigii Cabrera
and Grindelia chiloensis Cabrera.