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Phytomyza glabricola

Inkberry leafminer damage. Photo: Tracy S. Feldman, Bugguide.
Scientific Name: 
Phytomyza glabricola
Common Name: 
Inkberry Leafminer
Growing Degree Days (GDD's): 
100–149 (adults; approximately), Base 50F, March 1st Start Date (Source: Robert Childs, UMass Extension.)
Host Plant(s) Common Name (Scientific Name): 
Inkberry (Ilex glabra) (Johnson and Lyon, 1991)
Inkberry Holly (Ilex coriacea) (Manen et al. 2010) *Populations on this host may be a divergent species with differences in life cycle, despite morphological similarities (Herbert et al. 2016).
Insect Description: 

The inkberry leafminer is one of many related leafminers. It only mines and develops on the leaves of inkberry. Blotch mines are created by the larval feeding of this insect. Two generations are said to occur per year, however several may be possible and the life cycle in Massachusetts is not fully understood. (Adult emergence has been observed in early May in Massachusetts, Childs, Personal Communication.) On Ilex glabra, development time of this insect takes approximately 2-4 weeks. Adult flies emerge on both aforementioned hosts synchronously, around mid-January and mid-February in southern portions of its range (Herbert et al. 2016). However, the life cycle of this insect in New England is not currently well understood. In Ohio, two 1st instar larval peaks were observed in September and December and also again in June of the subsequent year of observation. Peak timing for 2nd and 3rd instar larvae of the Ohio populations observed was less obvious. In this study, peaks of pupation were observed in July and again in September with adult activity peaks in August and October. In a subsequent year of observations, adult flights were again observed in April, May, June, July, and September in Ohio. The data from this study varied depending upon whether the site was in the shade or sun. Four generations per year were estimated by their observations (Al-Siyabi and Shetlar, 1999). This study also estimated that in Ohio, inkberry leafminer pupae are the overwintering life stage. Al-Siyabi and Shetlar also observed that unlike the holly and native holly leafminers, inkberry leafminer adult females did not produce pinholes in host plant leaves and did not seem to feed on inkberry sap in their field observations (1999). Three or four generations are thought to occur per year in Ohio. Additional, related leafminers (holly leafminer, native holly leafminer) are found on similar hosts.

Damage to Host: 

Larvae create blotch mines in the foliage of inkberry (Ilex glabra).


Consider monitoring for adult emergence in Massachusetts with yellow sticky cards to help better time management decisions, if necessary. 

Cultural Management: 

Remove mined leaves before pupation/adult emergence. 

Natural Enemies & Biological Control: 

Information on the natural enemies of the inkberry leafminer is not available or well understood at this time.

Chemical Management: 

Abamectin (NL)

Acephate (NL)

Acetamiprid (L)

Azadirachtin (NL)

Bifenthrin (NL)

Clothianidin (NL)

Cyantraniliprole (NL)

Cyromazine (NL)

Diflubenzuron (N)

Dinotefuran (NL)

Emamectin benzoate (L)

Fenpropathrin (NL)

Flonicamid+cyclaniliprole (N)

Gamma-cyhalothrin (adults) (L)

Horticultural oil (L)

Imidacloprid (L)

Insecticidal soap (NL)

Lambda-cyhalothrin (adults) (L)


Neem oil (NL)

Permethrin (L)

Pyrethrin+sulfur (NL)

Spinosad (NL)


Active ingredients that may be applied systemically include: abamectin (injection), acephate (injection), acetamiprid (injection), azadirachtin (injection, soil drench), clothianidin (soil drench), cyantraniliprole (soil drench, soil injection), diflubenzuron (soil drench), dinotefuran (soil drench), emamectin benzoate (injection), imidacloprid (soil drench), and neem oil (soil drench).

Make insecticide applications after bloom to protect pollinators. Applications at times of the day and temperatures when pollinators are less likely to be active can also reduce the risk of impacting their populations.

Note: Beginning July 1, 2022, neonicotinoid insecticides are classified as state restricted use for use on tree and shrub insect pests in Massachusetts. For more information, visit the MA Department of Agricultural Resources Pesticide Program.

Read and follow all label instructions for safety and proper use. If this guide contradicts language on the label, follow the most up-to-date instructions on the product label. Always confirm that the site you wish to treat and the pest you wish to manage are on the label before using any pesticide. Read the full disclaimer. Active ingredients labeled "L" indicate some products containing the active ingredient are labeled for landscape uses on trees or shrubs. Active ingredients labeled "N" indicate some products containing the active ingredient are labeled for use in nurseries. Always confirm allowable uses on product labels. This active ingredient list is based on what was registered for use in Massachusetts at the time of publication. This information changes rapidly and may not be up to date. If you are viewing this information from another state, check with your local Extension Service and State Pesticide Program for local uses and regulations. Active ingredient lists were last updated: January 2024. To check current product registrations in Massachusetts, please visit: .