How to manage red mealybug in coffee

Considered unusual in coffee plantations in Brazil, the red scale insect Nipaecoccus coffeae was detected in the municipality of João Pinheiro, Minas Gerais, after a long period without being observed. Although it does not require special control measures, the pest requires monitoring and attention within integrated management strategies.

The red cochineal, Nipaecoccus coffeae (Hempel) (Hemiptera: Pseudococcidae) is part of the group of scale insects known as mealybugs and are sap-sucking insects that host various plants, both wild and ornamental and cultivated. In coffee plants, they are still considered secondary or occasional pests, however, in certain circumstances, they can cause losses in plants or bushes in the coffee plantation.

In integrated pest management, these scale insects must be included in the group of insects that must be monitored, but do not usually require special control measures.

There are approximately 15 species of mealybugs associated with the coffee tree in Brazil, occurring both in the roots and in the aerial part, which must have their populations monitored over time.

In September 2014, in the municipality of João Pinheiro, Minas Gerais, and within normal monitoring activities, an unusual mealybug was detected on the coffee plant. The mealybug colonies were located in the buds and coffee fruits at the pellet stage, with an abundant amount of web produced by them, where the adult insect, numerous eggs and small nymphs swarming around were found. The colony of these insects was composed of a cottony mass of white color, but the cochineal, unlike other species found on coffee trees that are white in color, was red in color and relatively large in size for this type of mealy cochineal (approximately 4 mm), hence the name of red coffee cochineal and whose scientific name is Nipaecoccus coffeae (Hempel) (Hemiptera: Pseudococcidae).

The interesting thing about this detection was that there were no written records of its presence since 1919, the date of its description by entomologist Adolfo Hempel, in samples obtained in the region of Campinas and São Paulo. The red scale insect may have remained in the coffee plantations all along, however, due to its low incidence and economic impact, it has not caused concern and has not been studied or reported.

The attack of the red scale insect in the place where it was detected occurred in isolated sectors and plants of the coffee plantation and its population remained limited to these places according to agronomist Eduardo Mosca. This situation is partly due to the characteristic of mealybugs of having low mobility, a particularity that results in a usually slow dispersion and localized presence or in clusters.

Populations tend to occur in dense colonies, preferably in shaded areas. Although populations of this cochineal are currently considered low and of no economic importance, monitoring them is important, as these insects are generally present for a long time in low densities and suddenly become pests, causing so-called outbreaks.

A natural enemy was found alongside the mealybugs, a fly from the Syrphidae family, but its impact and that of other control agents on the insect's populations is still unknown.

The biology of the red mealybug has not yet been studied due to the fact that it is an unusual insect and has gone unnoticed. Its presence has so far only been reported in Brazil, because it is possibly a native species, with a wild host still unknown and which has adapted to the coffee tree, which is an exotic plant. This situation is common among mealybugs, which are capable of feeding on plants from different families (polyphagous). The presence of adult females, eggs and first instar nymphs in September indicates that this time must correspond to the beginning of reproduction of the species.

With this detection, it is already known that its area of ​​occurrence covers the states of São Paulo and Minas Gerais, but new surveys could certainly expand this distribution in Brazil.

When monitoring mealybugs, the sites of infestation on plants, which are the roots and aerial parts, must be considered. When plants are uprooted, the presence of white wool and/or crypts (popcorn) on the roots may be an indication of mealybug attack, which results in plant decline. In the aerial part, and especially in shaded areas of the plants, when lifting the branches, mealybug colonies usually appear in compact groups (colonies). Sweet ants, generally associated with them and feeding on the secretions expelled by scale insects (sugar molasses), are a good indication for finding these insects. Dropped fruit with white masses or mealybugs should also be carefully examined. The presence of webs in the colony is also another indication of a red mealybug attack.

Control directed specifically against this mealybug is not necessary, considering the antecedents known to date. Systemic insecticides registered and used against the leaf miner must certainly exert some degree of control of this insect.

Sweet ants interfere with the action of natural enemies, and any control measure adopted will contribute to improving the efficiency of biological control.

How to manage mealybugs 

Ernesto Prado, Lenira V.C. Santa-Cecília, Paulo Rebelles Reis; Epamig Sul de Minas/EcoCentro, Support: Consórcio Pesquisa Café; Eduardo Mosca, coffee growing consultant

Article published in issue 199 of Cultivar Grandes Culturas.