Source: UNIVERSITY OF FLORIDA submitted to
BIOLOGY AND MANAGEMENT OF SCALE INSECTS (HEMIPTERA: STERNORRHYNCHA: COCCOIDEA) ON TROPICAL WOODY PLANTS AND PALMS.
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0201719
Grant No.
(N/A)
Project No.
FLA-FTL-04185
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2004
Project End Date
Sep 30, 2009
Grant Year
(N/A)
Project Director
Howard, F. W.
Recipient Organization
UNIVERSITY OF FLORIDA
G022 MCCARTY HALL
GAINESVILLE,FL 32611
Performing Department
FT. LAUDERDALE RESEARCH & EDUCATION CENTER
Non Technical Summary
Scale insects are among the worst pests of woody plants and among the most frequently introduced exotic invasive pests, but are poorly understood biologically. The purpose of this project is to elucidate the biology of exotic invasive and native scale insect pests and develop management methods for them.
Animal Health Component
40%
Research Effort Categories
Basic
50%
Applied
40%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2110621113050%
2110640113010%
2112110113040%
Goals / Objectives
To determine the bionomics of and develop management methods for native and exotic invasive scale insect pests in Florida, and to learn details of the biology of scale insects that can be applied towards improving integrated management of scale insect pests and which will advance our understanding of scale insects in general.
Project Methods
Research will be focused primarily on exotic invasive scale insect species, since information that can be applied towards managing them and curtailing their spread is of urgent importance. Studies will also be conducted on certain native scale insects that are important pests or that offer opportunities to advance our general knowledge of scale insects. Field observations will be conducted to determine aspects of the bionomics of scale insects, including host plant ranges, within-plant distribution and selection of feeding sites by scale insect crawlers, and polymorphism within scale insect species. Laboratory observations will be conducted to determine details of the biology of scale insects such as the behavior of crawlers, temperature relationships, and morphology of the scale cover. Rearing techniques will be developed for scale insect species that are targets of biological control programs. Insecticides will be tested for control of selected scale insect pest species in field trials with infested plants.

Progress 10/01/04 to 09/30/09

Outputs
OUTPUTS: Nothing to report. Dr. Howard is no longer at the University of Florida. Please terminate this project. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Nothing to report. Dr. Howard is no longer at the University of Florida. Please terminate this project.

Publications

  • No publications reported this period


Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: Research was continued to develop additional pest management options for lobate lac scale, Paratachardina psuedolobata, which is an introduced pest reported on more than 300 species of woody plants in Florida. In previous work we found that a root drench method with imidacloprid was effective in controlling this pest. An experiment initiated last year to compare the imidacloprid root drench method with insertion of imidacloprid tablets in the soil of containerized wax-myrtle, Myrica cerifera, for control of lobate lac scale was completed. The results were that the root drench treatment completely eliminated mature and first instar lobate lac scales. Several lobate lac scales survived on the plants treated with the tablets, but the difference between the tablet and drench treatments was within the margin of error. Observations of various researchers have indicated that imidacloprid may stimulate or otherwise accelerate plant growth rate. An experiment initiated last year to compare the growth rate of wax-myrtles treated with imidacloprid was completed. Data are being analyzed. Studies were continued of the field biology of the mahogany bark weevil, Copturus floridanus (Curculionidae). The nocturnal and diurnal feeding behavior of adult weevils was observed. Weevil exit holes were counted weekly over a 12-month period to compare the damage levels of mahogany bark weevils in West Indies mahoganies, Swietenia mahagoni, in trees stressed by girdling compared to ungirdled trees. The field work of this study was competed and data are being analyzed. A field study initiated last year of the erythrina gall wasp, Quadrastichus erythrinae, to determine the extent of its galling and associated damage to Erythrina spp. grown in Florida and other Southeastern States was completed. Hosts were observed in a research nursery and in natural and landscaped areas in southern Florida. In the research nursery, galling and resulting damage to E. herbacea L., a native plant, was highly variable on four different examination dates during a one-year period. On one examination date, when the susceptibility levels of three species of Erythrina were compared, there was a higher percentage of galled leaves on Erythrina variegata L., an Asian species grown as an ornamental in Florida, than on Erythrina herbacea, and minimal galling on Erythrina humeana, an African species. Based on several criteria, E. variegata was the more susceptible of the observed hosts. PARTICIPANTS: Dr. Hong Liu, Post-doctoral Fellow. Conducted research on the impact of lobate lac scale on plant growth and ecology and contributed to studies of the host range of lobate lac scale. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: This project is focused on the biology and management of scale insect pests of shrubs, trees, and palms, but during this reporting period some work was done on erythrina gall wasp and on mahogany bark weevil in response to outbreaks of these insects.

Impacts
The chemical treatment using tablets inserted in the soil for control of lobate lac scale may provide an option for managing this pest in nurseries and landscape situations which may be preferable in some situations to the root drench method developed in our previous work because of the ease and rapidity of applying tablets compared to administering drenches. This has broad application for control of scale insect pests in general. Knowledge of the field biology of the mahogany bark weevil will improve plant protection of West Indies mahogany, one of the most important tropical timber trees and an important shade tree in Florida and the Caribbean. The observations of host plant relationships of erythrina gall wasp increases understanding of this pest and its potential impact on Erythrina spp., which are important shrubs and trees in natural areas of the southern United States and the Caribbean, and in agriculture in Tropical America.

Publications

  • Howard, F.W., R. W. Pemberton, and Hong Liu 2008. Erythrina gall wasp, Quadrastichus erythrinae (Hymenoptera: Eulophidae) in Florida, and susceptibility of Erythrina herbacea (Fabaceae). Proceedings of the Florida State Horticultural Society 121: In Press.
  • Howard, F. W. 2008. Coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae). In John Capinera (ed.): Encyclopedia of Entomology, 2nd Edition, Kluwer Academic Publishers, Dordrecht. In press.
  • Howard, F. W. 2008. Mahogany pests and their management. In John Capinera (ed.): Encyclopedia of Entomology, 2nd Edition, Kluwer Academic Publishers, Dordrecht. In press


Progress 10/01/06 to 09/30/07

Outputs
OUTPUTS: Studies were continued on the biology and management of the lobate lac scale, Paratachardina lobata, (Kerriidae), an invasive pest that attacks at least 311 woody plants in Florida. Cooperative work with personnel of the USDA Invasive Plant Laboratory to develop biological control of lobate lac scale was continued, including studies of the natural history of this insect in Florida. Research cultures representing several families of Coccoidea including Coccidae, Dactylopiidae, Diaspididae, Diaspididae, and Kermesidae were maintained for use in evaluating the potential host ranges of natural enemies of lobate lac scale. Experiments were continued in three natural areas to determine the impact of lobate lac scale on native shrubs, including Myrica cerifera, Eugenia confusa, Pavonia paludicola, and Exothea paniculata. Since imidacloprid treatments provide a useful research tool for keeping plants free of scale insects so that their growth can be compared with scale-infested plants, an experiment was initiated to determine a suspected effect of imidacloprid on growth on several plant species. Another experiment was initiated to compare two methods of application of imidacloprid, viz., root drench and placement of capsules in the root zone, for control of lobate lac scale on woody plants. Some work was devoted to research on new urgent problems caused by pests other than scale insects, including the mahogany bark weevil, Copturus floridanus (Curculionidae), and the Erythrina gall wasp, Quadrastichus erythrinae (Hymenoptera: Eulophidae). A marked increase in damage due to C. floridanus was observed on West Indies mahoganies, Swietenia mahagoni, due to effects of Hurricane Wilma in October 2005, which continued into 2007. Observations were conducted to compare weevil adult and larval populations and activity on hurricane-damaged and undamaged trees, and to determine if weevils preferentially attacked damaged branches on otherwise healthy trees. An experiment was conducted in which C. floridanus damage was compared on stem-girdled mahoganies and controls. Data from these observations are being analyzed. Observations were conducted on Erythrina gall wasp soon after it was detected in Florida. Sticky-trap monitoring showed that adult wasps were in large numbers within crowns of Erythrina trees, but were rarely trapped at 8 m from infested trees. When exposed to Erythrina gall wasps, Erythrina indica and E. mulunga became highly galled, but E. humeana was not galled, and Erythrina herbacea, which is an Erythrina species native to the Southeastern US, was only moderately galled. Several insecticide treatments were tested, the results of which are being analyzed. Sticky-trap sampling and examination of older and recently planted Erytrhina in the Fort Lauderdale area indicated that since early 2007, there has been a marked decline in this wasp and associated galling due to unknown factors. PARTICIPANTS: Dr. Sibylle Schroer, Post-doctoral Fellow, conducted research on lobate lac scale biology and systematics, performed exploration for biological control agents of lobate lac scale in Asia, conducted rearing of natural enemies and their hosts in quarantine. Dr. Hong Liu, Post-doctoral Fellow. Conducted research on the impact of lobate lac scale on plant growth and plant ecology, and contributed to studies of the host range of lobate lac scale.

Impacts
Information obtained on insect pests in this project will be useful as a basis for developing and improving pest management practices for protection of woody plants. The chemical treatments developed in this project for lobate lac scale will provide effective control of this pest in nurseries and landscaped areas. Collaboration with biological control specialists to develop biological control will result in long range management of lobate lac scale. Knowledge of the host range of lobate lac scale will be useful in regulatory activities to prevent the spread of the pest, in selecting plants for landscaping, and evaluating the pest's impact on natural areas. Thus, tools for protecting the health of important plants in natural areas and urban landscapes will be made available. Data on mahogany bark weevils will contribute to a better understanding of the dynamics of this insect.

Publications

  • Howard, Forrest W., Robert Pemberton, Greg S. Hodges, Bryan Steinberg, David McLean and Hong Liu 2006. Host plant range of lobate lac scale, Paratachardina lobata, in Florida. Proceedings of the Florida State Horticultural Society 119: 398-408.
  • F. W. Howard and Dave Moor 2006. Coconut mite, Aceria guerreronis (English and Spanish versions.) Featured Creatures. http://creatures.ifas.ufl.edu
  • F. W. Howard 2006. The American palm cixiid, Mydus crudus. guerreronis (English and Spanish versions.) Featured Creatures. http://creatures.ifas.ufl.edu


Progress 10/01/05 to 09/30/06

Outputs
Studies were continued on the biology and management of the lobate lac scale, Paratachardina lobata, (Kerriidae), which is native to southern Asia and found in southern Florida in 1999. It has become a serious pest of woody plants in urban areas and in the Everglades. We have now recorded 311 host plants of this species (as indicated by development from settled crawler to adult on the same plant), thus lobate lac scale has one of the widest documented host ranges in the superfamily Coccoidea and probably the widest host range of a scale insect recorded in a single region. Cooperative work with personnel of the USDA Invasive Plant Laboratory to develop biological control of lobate lac scale was continued, including monitoring of field populations of the scale insect to obtain a baseline of the natural enemies already present, and completion of initial studies of the natural history of this scale insect in Florida. Research cultures that we previously established, representing several families of scale insects including Coccidae, Dactylopiidae, Kerriidae, and Diaspididae, were maintained for use in evaluating the potential host ranges of natural enemies of lobate lac scale that are to be discovered by USDA-ARS collaborators and studied in the USDA quarantine facility at Fort Lauderdale. Experiments were initiated in three natural areas to determine the effects of lobate lac scale on native shrubs, including Myrica cerifera, Eugenia confusa, Pavonia paludicola, and Exothea paniculata. In these studies the growth rates over time of infested and uninfested plants of each species are being compared. Studies commenced last year were continued on the field biology of West Indies mahogany scale, Conchaspis cordiae Mamet, a pest of West Indies mahoganies, Swietenia mahagoni, that was accidentally introduced into Florida from the Caribbean. In late fall 2005, the populations of C. cordiae that had been under observation were greatly diminished, apparently due to direct effects of wind and to extensive breakage of twigs and small branches of their West Indies mahogany hosts by Hurricane Wilma. By late summer 2006, the scale insect populations had recovered. Observations to understand the life history of this scale insect are still in progress. Many West Indies mahoganies in southern Florida were observed to be infested with a species of whitefly (Aleyrodidae) that is morphologically identical or similar to the woolly whitefly, Aleurothrixus flocossus Maskell. Since mahoganies are not normally hosts of whiteflies, uninfested containerized plants of guava, Psidium guajava, and sweet orange, Citrus sinensis, the two most common hosts of A. floccosus, plus uninfested mahoganies were placed in close proximity to mahoganies highly infested with the whitefly tentatively identified as A. floccosus. This aleyrodid infested the mahoganies but not guava or orange. indicating that it is possibly a cryptic species different from A. floccosus. Observations were initiated to determine the host plant range of Icerya genistae Hempel (Margarodidae), an adventive species of scale insect native to Brazil found this past year in Florida.

Impacts
Information obtained on scale insects in this project will be useful as a basis for developing and improving pest management practices for scale insect pests of woody plants. The chemical treatments to be developed in this project for several scale pests of ornamental plants will provide effective control of these pests in nurseries and landscaped areas. Collaboration with biological control specialists to develop biological control will result in long range management of several scale insect pests. Thus, tools for protecting the health of important plants in natural areas and urban landscapes will be made available.

Publications

  • Howard, F. W. 2006. Coconut Insects: Ecology and Control. 5 pp. in The Encyclopedia of Pest Management (David Pimentel, Ed.) Online at www.Dekker.com
  • Howard, F. W., G. S. Hodges, and Michael W. Gates 2006. First report of Conchaspis cordiae (Hemiptera: Conchaspididae) in Florida and the United States. Florida Entomologist 89: 102-104
  • Pemberton, Robert W., Ru Nguyen, Amporn Winotai, and F. W. Howard 2006. Host acceptance trials of Kerria lacca (Kerriidae) parasitoids from northern Thailand on the pest lobate lac scale (Paratachardina lobata)(Kerriidae) in Florida. Florida Entomologist 89: 336-339.
  • Howard, F. W. and B. Steinberg 2005. Root drenches and topical insecticide treatments for control of the lobate lac scale, Paratachardina lobata (Chamberlin). Proceedings of the Florida State Horticultural Society 118: 314-318


Progress 10/01/04 to 09/30/05

Outputs
This project is conducted to elucidate the field biology of scale insect pests, especially adventive species, and develop methods of managing them. The current focus is on lobate lac scale, Paratachardina lobata (Hemiptera: Sternorrhyncha: Coccoidea: Kerriidae), a species of scale insect native to Southern Asia that is now a highly invasive pest in Florida. The host list of this species was expanded to include 298 species of woody plants. Of various plants evaluated for use as rearing hosts for research on this scale insect and its natural enemies, Cocoplum, Chrysobalanus icaco (Chrysobalanaceae) was found to be highly suitable. Metaphycus sp. (Hymenoptera: Encyrtidae) was reared from lobate lac scale collected in the field. Based on sampling from diverse host plants and sites, the rate of parasitism of lobate lac scale in Florida is less than 1 percent. Research cultures representing various families of scale insects were established for use in evaluating the potential host ranges of natural enemies of lobate lac scale obtained in India by USDA-ARS collaborators and now in the USDA quarantine facility at Fort Lauderdale. Chemical treatments were evaluated for control of the lobate lac scale to provide an option additional to the imidacloprid root drench treatment that we developed earlier. Of seven treatments tested as topical applications for reducing the percentage of live lobate lac scales on wax-myrtle, Myrica cerifera (Myricaceae), bifenthrin and imidacloprid were highly effective based on sampling at 4 weeks post-treatment. Organocide (containing fish and sesame seed oils and lecithin), and malathion in combination with paraffinic horticultural oil, were moderately effective. The West Indies mahogany scale, Conchaspis cordiae (Hemiptera: Sternorrhyncha: Coccoidea: Conchaspididae), was reported for the first time in Florida and the Continental U.S. We conducted a survey and found this species to be widely distributed in the urban areas of southeastern Florida. The scale insect infests branches and main stems. West Indies mahogany (Swietenia mahagoni) and a mahogany hybrid (S. macrophylla X S. mahagoni) were found to be preferred hosts. Honduras mahogany (S. macrophylla) and African mahogany (Khaya nyasica) were marginal hosts. No additional plant species have been identified as hosts. Marietta sp. (Hymenoptera: Aphelinidae) was identified as a parasitoid of the West Indies mahogany scale.

Impacts
Information obtained on scale insects in this project will be useful as a basis for developing and improving pest management practices for scale insect pests of woody plants. The chemical treatments to be developed in this project for several scale pests of ornamental plants will provide effective control of these pests in nurseries and landscaped areas. Collaboration with biological control specialists to develop biological control will result in long range management of several scale insect pests. Thus, tools for protecting the health of important plants in natural areas and urban landscapes will be made available.

Publications

  • No publications reported this period


Progress 10/01/03 to 09/30/04

Outputs
This start date of this project was October 2004. In the first 3 months of this project, we continued field and laboratory studies initiated in CRIS Project FLA-FTL-03607 to elucidate the bionomics of the lobate lac scale, Paratachardina lobata (Chamberlin) (Hemiptera: Coccoidea: Kerriidae), an introduced pest in Florida. We have conducted tests to develop chemical control of this pest. Results are being analyzed. We have initiated collaborative research with biocontrol specialists to identify and ultimately use natural enemies against this pest in Florida. Studies of additional scale insect pests are being initiated.

Impacts
Information obtained on scale insects in this project will be useful as a basis for developing and improving pest management practices for scale insect pests of woody plants. The chemical treatments to be developed in this project for several scale pests of ornamental plants will provide effective control of these pests in nurseries and landscaped areas. Collaboration with biological control specialists to develop biological control will result in long range management of several scale insect pests. Thus, tools for protecting the health of important plants in natural areas and urban landscapes will be made available.

Publications

  • Howard, F. W., and R. Pemberton. 2004. The lobate lac scale insect, a new pest of trees and shrubs in Florida: implications for the Caribbean Region. Pp. 91-94 in W. Klassen (ed.), Proceedings of the Caribbean Food Crops Society, 39(1), 2003.