For a slightly more extensive summary that doesn't require someone to read 20-page paper... Jeffrey Lockwood (who also wrote a book on the topic of entomological warfare, writes in a 2012 paper broader in scope:
Yellow fever became the mainstay of the Camp Detrick’s entomological program, when it was
discovered that mosquito larvae would uptake the virus from an aqueous medium, allowing the
mass production of infected adults without the need for blood feeding (43, 44). The U.S. military
then conducted an extensive series of simulated attacks using uninfected mosquitoes.
In 1955, Operation Big Buzz involved the production and storage of more than one million A.
aegypti. The test in rural Georgia was considered successful when the mosquitoes reached human
volunteers and guinea pigs 1 km from the release site (44, 58, 92). Subsequent trials (Operations
Drop Kick and Gridiron) (44) were sufficiently promising that the U.S. military conducted a
simulated attack on an American city. From April to November of 1956, the people of Savannah,
Georgia, served as uninformed targets. In Operation May Day, mosquitoes were released as if
dispersed from bombs and warheads (92). This trial was followed by the Avon Park Experiment
in which 200,000 mosquitoes were released over Florida using a new “bagged-agent dispenser”
with a 320-kg payload consisting of 2,090 paper bags loaded with insects.
The Bellwether tests in 1959 were conducted to refine the American understanding of entomological warfare (44). Bellwether One involved field experiments designed to assess the role of
environmental factors on the capacity of mosquitoes to find and feed on hosts. In Bellwether Two,
researchers monitored the biting frequency of mosquitoes and found that a single release would
infest an area of approximately 1 hectare. Detailed observations revealed that humans moving
erratically and near buildings were bitten most frequently, which boded well for an attack on an
urban setting. The details of Bellwether Three remain classified, but Bellwether Four consisted of
testing strains of mosquitoes that had been bred for aggressive host seeking and biting. Researchers
also produced insect strains resistant to insecticides as these “represent a potentially more effective
vehicle for the offensive use of BW [biological warfare] of insect borne pathogens” (27).
In 1960, the U.S. Army Chemical Corps issued an “Entomological Warfare Target Analysis”
to identify vulnerable sites for an attack (44, 74). China and the Soviet Union had many cities that
met the criteria, and in the judgment of the analysts, it “would be impossible for a nation such
as the USSR to quickly undertake a mass-immunization program to protect millions of people”
(74). In the same year, plans were drawn up for a facility at Pine Bluff, Arkansas, with the capacity
to produce 130 million infected mosquitoes per month (43, 65)
Apparently the facility never went into production though, a fate it shared with another (location not mentioned) "planned to produce 50 million fleas per week, until microbiologists proved unable to culture enough plague bacteria".
Operation Magic Sword
assessed the capacity of yellow fever mosquitoes to make landfall after being released from a ship
anchored off the warm, humid shores of the United States to approximate the tropical conditions
of southeast Asia (44).
And an amusing, perhaps, footnote from the book (p. 344):
During Soviet inspections of U.S. facilities in 1991, the Russians requested
access to the “mosquito room” at Pine Bluff Arsenal. Finding a massive
water-filled vat with newly refitted plumbing, the Soviets were certain they’d
found evidence of an active, offensive program in entomological warfare. The
Americans admitted that the pool had been updated, but they were able to
show that the modified tank was not being used to produce mosquitoes for
military operations but to raise catfish for civilian research.
(One might be a bit skeptical of this last story, but there were such visits conducted by the Soviets in December 1991 [Verification Yearbook 2002, p. 96] in preparation for the 14 September 1992 Trilateral Agreement--which eventually didn't fare too well.)