Observations on the effect of the weevils Neochetina eichhorniae Warner and Neochetina bruchi Hustache on the growth of water hyacinth

1984 ◽  
pp. 95-98
Author(s):  
M. O. Bashir ◽  
Z. E. El Abjar ◽  
N. S. Irving
Keyword(s):  
Water Hyacinth ◽  
Neochetina Eichhorniae

The pathogenicity of an Australian isolate of Acremonium zonatum to water hyacinth, and its relationship with the biological control agent, Neochetina eichhorniae

1987 ◽  
Vol 38 (1) ◽  
pp. 219 ◽  
Author(s):  
JC Galbraith
Keyword(s):  
Biological Control ◽  
Water Hyacinth ◽  
Biological Control Agent ◽  
Control Agent ◽  
Control Programme ◽  
Australian Isolate ◽  
Free Moisture ◽  
Neochetina Eichhorniae ◽  
Dry Conditions ◽  
The Individual

The first description of Acremonium zonatum on water hyacinth in Australia is made. Its pathogenicity was studied as part of the search for a microorganism already present in Australia which could be developed as a mychoherbicide to supplement the arthropod biological control programme in this country. Following inoculation with A. zonatum, extensive leaf infections developed, favoured by injury and free moisture, but new leaves continued to form. Feeding by the weevil, Neochetina eichhorniae, increased infection by A. zonatum in relatively dry conditions, but it is unlikely that this was due to feeding scars acting as ports of entry. A. zonatum spores were transported on the feet and in the digestive tract of the weevil. The growth of infected plants, estimated by standing crop, was reduced by 49% compared to the control. A further decrease occurred in infected plants infested by weevils, but the total reduction in growth was not equal to the sum of the individual effects of fungus and weevil. Infection did not develop in 15 other plant species inoculated with the Australian isolate of A. zonatum. Although not a virulent pathogen, A. zonatum has some favourable characteristics for consideration as a mycoherbicide and has not appeared antagonistic to N. eichhorniae in these studies. Its role probably lies in exerting a chronic stress on plants already under attack by arthropod biological control agents.

Changes in leaf hardness and moisture content of water hyacinth, Eichhornia crassipes, following feeding by Neochetina eichhorniae Warner (Coleoptera: Curculionidae)

1989 ◽  
Vol 79 (4) ◽  
pp. 529-535 ◽  
Author(s):  
A. D. Wright ◽  
N. P. Boland ◽  
J. D. Kerr
Keyword(s):  
Moisture Content ◽  
Water Hyacinth ◽  
Eichhornia Crassipes ◽  
Leaf Age ◽  
Field Observations ◽  
Neochetina Eichhorniae ◽  
Relative Abundances

AbstractFeeding by adults of Neochetina eichhorniae Warner on water hyacinth, Eichhornia crassipes, significantly increased the hardness of the lamina of the youngest leaf and the petioles of the youngest three leaves, while the moisture content of the petioles and laminae was significantly reduced. However, variations in leaf hardness did not significantly affect feeding by the weevils, and leaf age was considered to have a greater effect. The results help explain field observations of the relative abundances of N. eichhorniae and the pyralid Sameodes albiguttalis (Warren), which also attacks water hyacinth.

scholarly journals Mottled Water Hyacinth Weevil Neochetina eichhorniae Warner (Insecta: Coleoptera: Curculionidae)

EDIS ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. 5
Author(s):  
Eutychus Kariuki ◽  
Carey Minteer
Keyword(s):  
United States ◽  
Water Hyacinth ◽  
Biological Control Agent ◽  
The United States ◽  
Control Agent ◽  
Broward County ◽  
Invasive Weed ◽  
Invasive Aquatic Plant ◽  
Neochetina Eichhorniae ◽  
Noxious Weed

Sometimes referred to as the ‘mottled water hyacinth weevil’, Neochetina eichhorniae Warner is a weevil that attacks the invasive, aquatic plant, water hyacinth, Eichhornia crassipes (Mart.) Solms. Water hyacinth is considered one of the most destructive plants in aquatic ecosystems in the United States and, as a result, is listed in both the federal noxious weed list and Florida’s list of prohibited aquatic plants. Neochetina eichhorniae is host specific and causes substantial damage to water hyacinth, making it a valuable biological control agent for this invasive weed in many parts of the world. The insect was first introduced into the United States from Argentina in 1972, when scientists released the insect in Broward County, Florida, to manage water hyacinth (Perkins 1973). Since then, the insect has been introduced in more than three dozen countries worldwide (Winston et al. 2014). Post-introduction studies indicate the insect substantially suppresses the growth of water hyacinth, significantly reducing biomass, flowers production, and water surface coverage (Grodowitz et al. 1991, Center et al. 1999, Tipping et al. 2014, Nesslage et al. 2016) and the need for herbicide applications (Haag 1986).

scholarly journals Host spectrum, reproduction, and survival of Neochetina eichhorniae (Coleoptera: Curculionidae) - A potential natural enemy for controlling water hyacinth (Eichhornia crassipes)

2021 ◽  
Vol 20 (04) ◽  
pp. 10-16
Author(s):  
Dat T. Nguyen
Keyword(s):  
Life Cycle ◽  
Natural Enemy ◽  
Water Hyacinth ◽  
Ipomoea Batatas ◽  
Eichhornia Crassipes ◽  
Mangifera Indica ◽  
Egg Laying ◽  
Water Spinach ◽  
Female Ratio ◽  
Neochetina Eichhorniae

Neochetina eichhorniae (Coleoptera: Curculionidae) is a natural enemy of water hyacinth and its morphology as well as biology has been investigated previously. In this study, the host range of N. eichohorniae was examined using the following 7 groups of plants: Pontederiaceae (water hyacinth, Eichhornia crassipes; hastate-leaf pondweed, Monochoria hastata); food crops (rice, Oryza sativa; maize, Zea mays; sweet potato, Ipomoea batatas and cassava, Manihot esculenta); vegetables (cucumber, Cucumis sativus; mustard greens, Brassica juncea; turnip, Raphanus sativus; water spinach, Ipomoea aquatica; pepper elder, Peperomia pellucida; cabbage, Brassica oleracea var. capitata); herbaceous (boat lily, Tradescantia discolor, gotu kola, Centella asiatica, purple-heart, Tradescantia pallida); fruits (mango, Mangifera indica; longan, Dimocarpus longan; rambutan, Nephelium lappaceum); water plants (sacred lotus, Nelumbo nucifera; red water lily, Nymphaea rubra, yellow bur-head, Limnocharis flava) and industrial plants (sugarcane, Saccharum ssp.; peanut, Arachis hypogaea). The N. eichohorniae was found to be the only survivor that developed and completed its life cycle on water hyacinth. The N. eichohorniae caused only minimal damage to hastate-leaved pondweed and its life cycle was not completed on this weed. When fed with water hyacinth, N. eichohorniae female produced 358.9 eggs on average and the egg-laying period was 16 weeks. Forty three percent of eggs were laid from the 5th to the 8th weeks after females emerged from cocoons. The hatchability of N. eichohorniae eggs was 75.2% and 66.8% of the larvae could survive and became pupae. Approximately 79.1% of the pupae emerged as adults. Among the adults, the female ratio was 48.7%. These results indicated that N. eichohorniae could be considered as a natural enemy to be used for biological control of water hyacinth.

scholarly journals Chevroned Water Hyacinth weevil Neochetina bruchi Hustache (Insecta: Coleoptera: Curculionidae)

EDIS ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. 6
Author(s):  
Eutychus Kariuki ◽  
Carey Minteer
Keyword(s):  
United States ◽  
Biological Control ◽  
Water Hyacinth ◽  
Gulf Coast ◽  
Biological Control Agent ◽  
The United States ◽  
Control Agent ◽  
Weed Biological Control ◽  
Invasive Aquatic Plant ◽  
Neochetina Eichhorniae

Neochetina bruchi Hustache is commonly referred to as the chevroned water hyacinth weevil and is a weed biological control agent used to manage water hyacinth, Pontederia crassipes Mart. [formely Eichhornia crassipes (Mart.) Solms (Pellegrini et al. 2018)], in more than 30 countries (Winston et al. 2014). Imported from Argentina, the insect was first introduced into the United States in Florida in 1974 and released in Louisiana later in 1974 (Manning 1979), Texas 1980, and California 1982 to 1983 (Winston et al. 2014). Now Neochetina bruchi occurs throughout the Gulf Coast States (Winston et al. 2014). The target weed of Neochetina bruchi, water hyacinth, is an invasive aquatic plant in the United States and is included on Florida’s list of prohibited aquatic plants. Neochetina bruchi is among four species of insect biological control agents that have been introduced into the United States to manage water hyacinth. The other three species include a weevil, Neochetina eichhorniae; a moth, Niphograptaalbiguttalis; and a planthopper, Megamelus scutellaris, which were introduced into the United States in 1972, 1977, and 2010, respectively (Tipping et al. 2014). Although the larvae and pupae of Neochetina bruchi and Neochetina eichhorniae have similar appearance and behavior and can be difficult to differentiate by casual observation (Deloach and Cordo 1976), the adult stages of the two species of water hyacinth weevils can be distinguished relatively easily based on the color patterns on their elytra (hardened fore wings).

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