Acta Biológica Colombiana

Monalonion Herrich-Schaeffer is a genus of the subfamily Bryocorinae (tribe Monaloniini) with Neotropical distribution (Namyatova et al., 2016), which comprises 16 valid species (Schuh, 2002; Schuh, 2013). In Colombia, there are six recorded species (Distant, 1917; Schuh, 2002; Giraldo and Benavides, 2012; Schuh, 2013), although a detailed survey of those present in the country and their distributions has never been carried out. Monalonion species from Colombia, known exclusively from rural areas, are: M. annulipes Signoret, M. atratum Distant, M. columbiensis Carvalho, M. dissimulatum Distant, M. itabunensis Carvalho, and M. velezangeli Carvalho and Costa (Distant, 1917; Carvalho, 1972; Carvalho, 1984; Carvalho and Costa, 1988; Schuh, 2002; Schuh, 2013).

Some of these Monalonion species are important pest species of cacao (Theobroma cacao L., Malvaceae) (Abreu, 1977), guava (Psidium guava L., Myrtaceae) and avocado (Persea americana Mill., Lauraceae) in Central and South America (Distant, 1917; Wille, 1944; Wheeler, 2000). Monalonion velezangeli is also a pest of the economic importance of coffee (Coffea arabica L., Rubicaeae) in Colombia (Giraldo and Benavides, 2012).

Monalonion velezangeli was described from specimens collected in 1984 in Antioquia on avocado orchards (Carvalho and Costa, 1988). Monalonion velezangeli is a polyphagous plant bug associated in Colombia with 14 plant species of Myrtaceae (5), Rubiaceae (2), Lythraceae (1), Clusiaceae (1), Rosaceae (1), Malvaceae (1), Melastomataceae (1), Anacardiaceae (1), and Theaceae (1), which include economically important fruit, ornamental, and forest plantations (Giraldo and Benavides, 2012; Londoño et al., 2014; Rodas et al., 2014)(Table 1).

Table 1: Plant associations of Monalonion velezangeli Carvalho and Costa (Hemiptera: Miridae) in Colombia.

Species with ^a indicates all the plants present in Bogotá; ^b New plant association.

Monalonion velezangeli is characterized by its mostly black and dark yellow body, the presence of two or more red markings on the forewing membrane, and the white band on the femora (Carvalho and Costa, 1988; Giraldo et al., 2010; Fig 1a-1b). It might be confused with M. parviventre Herrich-Schaeffer by the red spots on the forewing membrane and with M. atratum by the color of the femora (Carvalho, 1972; Carvalho and Costa, 1988).

Figure 1: (a) Female of Monalonion velezangeli; (b) Male of Monalonion velezangeli; (c) Urban tree strongly affected by Monalonion velezangeli; (d) Dried leaves with reddish-brownish coloration; (e) Twig with necrotic lesions; (f) Twig malformation affecting bud development.

Many species of Monalonion exhibit polychromatism (Carvalho, 1972; Costa et al., 2008), including M. velezangeli (e.g., Giraldo et al., 2010), as exemplified by the coloration of the type series of M. velezangeli , in which most of the paratypes are mostly dark yellow in contrast to the mostly dark holotype (Carvalho and Costa 1988; J.A. Quiroz, pers. comm.).

Bogotá is a city located in the high Andes of Colombia at 2650 meters above sea level (4°35'56''N; 74°04'51''W). This is the largest city of Colombia with over 7 million people and approximately 1637 km² of extension. Due to this high elevation, Bogotá has a cold climate (average 17 °C) with two wet periods in the year occurring between March to May and September to November. Bogotá has many public and private green areas including parks, greenways, wetlands, and others (Alcaldía Mayor de Bogotá, 2017).

Entomological surveys focusing on urban trees planted in public parks and greenways in the northern portion of Bogotá were carried out irregularly, from May 2016 to March 2018, using sweep nets and entomological aspirators.

All specimens were identified using original descriptions and taxonomic keys (Carvalho, 1972; Carvalho, 1984; Carvalho and Costa, 1988). Collected specimens exhibit polychromatism, as documented before (Carvalho and Costa, 1988). Examined specimens are as follow 3 males and 1 nymph on Liquidambarstyraciflua, 2 males, 1 nymph on Pittosporum undulatum; 1 male on Ficus americana subs. andicola; 2 males and 2 females on Quercus humboldtii; 1 nymph on Acca sellowiana; 1 female on Prunus serotina; 6 males, 5 females and 1 nymph on Lafoensia acuminata; 6 males and 1 nymphs Schinus molle; 1 nymph in Cedrela montana; all deposited in the Entomology collection of the Museo Javeriano de Historia Natural Lorenzo Uribe S.J., of the Pontificia Universidad Javeriana (MUPJ_ENT), with catalog numbers MPUJ_ENT 0058309-MPUJ_ENT 0058344.

Monalonion velezangeli was found on different botanical species planted in public green areas of Bogotá. This is also the first report of this mirid species in an urban ecosystem at such a high altitude, which is noteworthy given that in Colombia most published records are below 2000 ma.s.l (Ramírez-Cortés et al., 2008) with occasional ones up to 2300 ma.s.l. in rural areas (Torres Jaimes et al., 2012). These records from Bogotá might represent recent introductions of M. velezangeli, and if so, they could be further evidence that environmental conditions are changing in Bogotá.

We also document for the first time the association of M. velezangeli with five new plant families (Pittosporaceae, Moraceae, Altingiaceae, Fagaceae and Meliaceae), increasing the number of reported species known for Colombia and other Andean countries from 14 to 19 (Table 1). Monalonion velezangeli was also collected on Lafoensia acuminata (Lythraceae), which was recorded previously as a host plant for this species (Londoño et al., 2014). Given the complex relationship between plants and Miridae (Wheeler, 2001), it is usually difficult to clearly assess if a plant species truly represents a host plant. Occasional occurrences of adults on various plants might represent visitors or indicate that they use the plant as an alternative feeding resource. In Bogotá, L. acuminata, L. styraciflua and S. molle can be considered host plants of M. velezangeli because we consistently found nymphs on these plants. Because nymphs cannot fly to reach other trees, we assume that their presence in a given plant species are an indication of true host plants, because these plants species might support nymphal development (Wheeler, 2016). Further studies are required to assess which plant species are better hosts for the reproduction of M. velezangeli.

Among the new plant species associated with M. velezangeli in Bogotá, the false pepper (S. molle) was observed injured by this plant bug. The damage was observed on the leaves and twigs of the tree, especially on young tissues; it is characterized by the presence of reddish-brownish necrotic lesions around the insect feeding site. As a result, dried leaves and twigs begin to appear (Fig. 1c-1e). These symptoms resemble those reported by Rodas et al. (2014) on Eucaliptus grandis W. Hill ex Maiden, mainly on young trees, and by Giraldo and Benavides (2012) in other hosts such as guava, avocado and coffee. Moreover, tissue malformations are commonly observed, particularly on young stems, inhibiting the formation of new buds (Fig. 1f). Both nymphs and adults seem to be responsible for the damage to S. molle, even when low levels of infestation by M. velezangeli were recorded. It is possible that morphological damage on this host tree is also related with secondary infections by phytopathogens. Recently it has been observed symptoms related to pathogenic infection by Verticillum spp. in shoots on several population of S. molle in green urban spaces in Bogotá (G.L. Sánchez, pers. comm.). Further studies to test this hypothesis are needed as well as studies that evaluate if the new plants species associated with M. velezangeli are used as feeding resources or also as oviposition substrates. Moreover, studies on the biology of M. velezangeli and its role as a pest in urban trees in Bogotá are necessary.