IP Law Daily, PATENT—M.D. Fla.: Court construes ‘mesh‘ in plant-cover patents to require insect-blocking feature, (Feb 13, 2026)

By Saurabh Kashyap, B.A., M.A., LL.B., LL.M.

A commercial company in the niche market for protective covers designed to combat citrus greening disease alleged infringement by a competitor.

A federal district court in Florida construed the disputed claim term “mesh” in two plant-cover patents to mean a net-like material that allows water permeability and light transmissivity while preventing intrusion by small insects such as psyllids. The court rejected the defendant’s broader construction, holding that the intrinsic record, particularly the specification and prosecution history, showed the patentee had clearly narrowed the term’s ordinary meaning through implied definitions and prosecution disclaimer (Tree Defender, LLC v. Mike Hurst Citrus Service Inc., No. 8:24-cv-02520-VMC-NHA (M.D. Fla. Feb. 11, 2026)).

Background. The plaintiff, Tree Defender, LLC, designs, manufactures, and sells protective individual plant covers used to shield young citrus trees from disease. The defendant, Mike Hurst Citrus Service, Inc., operates in the same market and produces competing plant covers. The parties are direct commercial competitors in the niche market for protective covers designed to combat citrus greening disease.

The dispute involved U.S. Patent Nos. 11,730,092 (the ’092 patent) and 12,058,965 (the ’965 patent), both titled “Plant cover with insect-resistant bag for enclosing a plant.” The patents concern breathable protective bags placed over young citrus trees to block insects that transmit citrus greening disease while still allowing air, water, and sunlight to pass through.

Tree Defender filed the infringement action alleging that Hurst Citrus’s plant covers infringed its patented technology. During claim construction proceedings, the parties narrowed their dispute to a single term—“mesh.” Tree Defender proposed that the term required insect-blocking capability, while Hurst Citrus argued for a broader meaning limited to a net-like material permitting water and light transmission.

Claim language. The court began with the claims themselves, noting that none defined “mesh” or expressly referenced insects. Applying Federal Circuit precedent, including Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576 (Fed. Cir. 1996), and Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005), the court held that the term should initially be given its ordinary meaning as understood by a person of ordinary skill in the art. However, the absence of an explicit claim definition required close examination of the specification.

Specification analysis. Turning to the intrinsic record, the court found that the patents’ titles, technical field descriptions, and background sections consistently characterized the invention as insect-repelling plant covers designed to prevent the spread of citrus greening disease by psyllids. The court concluded that these portions impliedly defined “mesh” as including insect-blocking functionality.

Although the detailed description sections included disclaimers stating that embodiments should not limit claim scope, the court held that those disclaimers did not negate the broader characterization of the invention throughout the specification. Citing Alloc, Inc. v. Int’l Trade Comm’n, 342 F.3d 1361 (Fed. Cir. 2003), the court explained that a limitation must be treated as inherent where the specification, read as a whole, shows it to be central to the invention’s character.

Prosecution history disclaimer. The court found the strongest support for Tree Defender’s position in the prosecution history of a related parent application. During examination, the applicant expressly argued that the specification defined “mesh” as material that permits water and light transmission but prevents the intrusion of small insects such as psyllids. The court held that these statements constituted an unequivocal disavowal of broader interpretations.

Relying on Omega Engineering, Inc. v. Raytek Corp., 334 F.3d 1314 (Fed. Cir. 2003), and Spectrum International, Inc. v. Sterilite Corp., 164 F.3d 1372 (Fed. Cir. 1998), the court ruled that explicit arguments made to distinguish prior art during prosecution narrow claim scope and bind continuation patents. It therefore concluded that the applicant had clearly relinquished any construction that did not include insect-blocking capability.

Rejection of defendant’s arguments. The court rejected Hurst Citrus’s contention that the proposed construction improperly added an unexamined limitation. It held that the limitation arose directly from the prosecution disclaimer and thus reflected the true scope of the patented invention.

The court also dismissed the defendant’s argument that Tree Defender’s interpretation improperly created a means-plus-function limitation. Applying Dyfan, LLC v. Target Corp., 28 F.4th 1360 (Fed. Cir. 2022), the court found that “mesh” connoted a definite structural material and therefore did not fall within 35 U.S.C. § 112(f).

Validity-preserving construction. Finally, the court rejected the suggestion that Tree Defender sought a narrow construction merely to avoid prior art invalidity. Citing Liebel-Flarsheim Co. v. Medrad, Inc., 358 F.3d 898 (Fed. Cir. 2004), the court explained that while courts may interpret claims to preserve validity where ambiguity exists, they may not rewrite clear claim scope. Because the intrinsic evidence already established a clear meaning, the court held that its construction simply applied, not altered, the patent’s defined scope.

Outcome. The court therefore adopted a construction defining “mesh” as a net-like material that permits water permeability and light transmissivity while preventing intrusion by small insects. It ordered that the disputed claim language in the case be construed accordingly.

The Case is No. 8:24-cv-02520-VMC-NHA.

Judge: Covington, V.

Attorneys: Ryan Thomas Santurri (Allen, Dyer, Doppelt, & Gilchrist, PA) for Tree Defender, LLC. Richard Edson Fee (Fee & Jeffries PA) for Mike Hurst Citrus Service Inc.

Companies: Tree Defender, LLC; Mike Hurst Citrus Service Inc.

Cases: Patent FloridaNews