Life History and Laboratory Host Range ofEccritotarsus catarinensis(Carvalho) (Heteroptera: Miridae), a New Natural Enemy Released on Water Hyacinth (Eichhornia crassipes(Mart.) Solms-Laub.) (Pontederiaceae) in South Africa

Survival of the mirid Eccritotarsus catarinensis as influenced by Neochetina eichhorniae and Neochetina bruchi feeding scars on leaves of water hyacinth Eichhornia crassipes

“…Low quality plants have been shown by Coetzee (2004) to adversely influence mirid development. However, due to its high rate of increase and a short life cycle of the mirid (Hill et al, 1999b;Stanley and Julien, 1999), even on leaves with more than 200 old feeding scars some immatures developed, thus ensuring a new generation. Cages with plants with fresh feeding scars, despite better survival of adult mirids, offered reproductive conditions for the mirids that were slightly worse than the control.…”

“…Fresh weevil feeding scars are made mainly in the night because adults are primarily nocturnal (DeLoach and Cordo, 1976). On the contrary, the mirid is mainly active in the day (Hill et al, 1999b), but despite this temporal separation, both taxa potentially compete for the same resources on the second and third leaf of their shared host. Both weevil species and the mirid have been established in South Africa and Malawi, (Cilliers et al, 2003) and the mirid may well be released in other countries where the weevils are already established (Coetzee et al, 2003).…”

“…Among the six agents released world wide (Harley, 1990;Julien et al, 1999), two weevil species, Neochetina eichhorniae (Warner) and N. bruchi Hustache (Coleoptera: Curculionidae) first released in early 1970s , are widely distributed in Africa (Cilliers et al, 2003). The mirid Eccritotarsus catarinensis (Carvalho) (Heteroptera: Miridae), was only recently released, first in South Africa in 1996 (Hill et al, 1999b) and in Benin in 1999, where it failed to establish.…”

“…The life cycle of the sap sucking mirid takes about 3 weeks and adults are active mostly during the day, when females insert their eggs into water hyacinth leaf blades. The nymphs are also diurnal and live and feed mainly on the leaf surfaces (Hill et al, 1999b;Stanley and Julien, 1999). Both weevil species are more active at night, when they feed on leaf surface and their life cycle varies between 72 and 120 days (Julien et al, 2001).…”

“…Adults and immature mirids live their entire lives on water hyacinth leaves, causing the yellowing of leaves through the feeding action of both stages (Hill et al, 1999b). For the two weevils, damage is caused by adults feeding on the leaves, creating pits called ''scars'' where the epidermis is removed; and larvae tunnel in the petiole and crown (Center, 1987), but our concern in this study is the feeding damage.…”