Damage caused by thrips (Thysanoptera: Thripidae) to several plant species in Brazil is described and illustrated for the first time, namely: Caliothrips phaseoli (Hood) and Dinurothrips hookeri Hood to Mentha sp. (Lamiales: Lamiaceae); Frankliniella insularis (Franklin) to varieties of Rosa × grandiflora Lindl. (Rosales: Rosaceae); Heliothrips haemorrhoidalis (Bouché) to Plumeria sp. (Gentianales: Apocynaceae); Retithrips syriacus (Mayet) to Terminalia catappa L. (Myrtales: Combretaceae) and Rosa sp.; and Selenothrips rubrocinctus (Giard) to Calophyllum brasiliense Cambess (Malpighiales: Calophyllaceae) and Liquidambar styraciflua L. (Saxifragales: Altingiaceae). The associations between R. syriacus and plants have been reported previously, but information on damage caused by this species is sparse or nonexistent. All other plant associations herein mentioned are first records.
Most studies on Thysanoptera in Brazil deal with species of agricultural importance (Alves-Silva & Del-Klaro 2010). Because few studies have treated the thrips fauna in this country (Monteiro 2002; Mound 2014), information on distribution and damage, even for native or long-introduced species, is scarce. Here, we report damage caused to 7 crop plants by 6 native or long-introduced thrips species (Thysanoptera: Thripidae) in Brazil. Associations involving Retithrips syriacus (Mayet) were previously known, but descriptions of the damage caused by these species are superficial or lacking. All other records presented here represent new plant associations (Table 1).
Thrips were collected occasionally from Jan 2012 to Oct 2014 in several Brazilian states (details in Material Examined), preserved in vials with AGA solution (glacial acetic acid, glycerin, and 60% ethylic alcohol at 1:1:10) or 60% ethylic alcohol, and mounted on permanent microscope slides (Mound & Marullo 1996) for identification. Voucher specimens were deposited at the Thysanoptera collection of the Escola Superior de Agricultura “Luiz de Queiroz” (ESALQ/USP) and at the Coleção de História Natural da Universidade Federal do Piauí (CHNUF-Pl). Adults and immatures were collected and identified (Speyer & Parr 1941; Heming 1991; Vierbergen et al. 2010) in all surveys, enabling the establishment of host associations.
Caliothrips phaseoli (Hood) and Dinurothrips hookeri Hood were observed associated with damage on leaves of mint, Mentha sp. (Lamiales: Lamiaceae). Although the 2 species were found together, the few specimens of C. phaseoli collected were probably incidental. Caliothrips phaseoli is an important pest of common bean and soybean, especially in dry seasons (Monteiro et al. 1999). The injuries on mint caused silvering of leaves, with consequent necrosis (Fig. 1a–c). A high infestation of D. hookeri was observed, which led to the death of mint plants. In Brazil, D. hookeri is not known as a pest of any crop.
Frankliniella insularis (Franklin) (Fig. 1d) caused puncture marks and light and dark patches of various sizes (Fig. 1e–g) on rose (varieties of Rosa × grandiflora Lindl.; Rosales: Rosaceae) flowers. As the appearance is important for consumer acceptance, sales of these ornamentals are compromised by thrips attack. At the collection site, successful releases of Orius insidiosus (Say) (Heteroptera: Anthocoridae) were performed to reduce the thrips population. Frankliniella insularis has been reported as a minor pest of legumes such as pigeon pea (Cajanus species) and yam bean (Pachyrhizus species) (Fabales: Fabaceae) in Central America (Hoddle et al. 2012). In Brazil, it has also been reported as a pest of orange (Sapindales: Rutaceae) (Bondar 1929), but in view of the confusion regarding the taxonomy of Frankliniella in the beginning of the 20th century and the lack of voucher specimens (Cavalieri & Mound 2012), this record likely represents a misidentification. Since then, F. insularis has not been recorded as a pest of any crop plants in the country (Monteiro et al. 1999; Lima 2013).
Heliothrips haemorrhoidalis (Bouché) (Fig. 1h and i) caused the appearance of chlorotic spots on the upper sides and undersides of leaves of Plumeria sp. (frangipani) (Gentianales: Apocynaceae). Characteristic and abundant dark spots (fecal material) were observed (Fig. 1j and k). This polyphagous pest thrips is widely recorded in Brazil, where it is associated with more than 20 plant species (Monteiro et al. 1999; Lima et al. 2012).
Associations between R. syriacus (Fig. 1l and m) and Rosa sp. (rose) (Rosales: Rosaceae) and Terminalia catappa L. (tropical almond) (Myrtales: Combretaceae) were previously known, but information on damage is scarce and mostly available only from a few papers published in the beginning of the 20th century (Bondar 1924,1926). The damage to both plant species was similar, i.e., silvering, especially near the veins (Fig. 1n and o). Dark spots (fecal material) could be seen at the sites of insect feeding. In roses, heavier damage than in almond was observed, sometimes on the entire leaf (Fig. 1o). In Brazil, R. syriacus is a pest of grapevines (Vitis species; Vitales: Vitaceae), eucalyptus (Eucalyptus species) (Myrtales: Myrtaceae) (Monteiro et al. 1999) and physic nut (Jatropha curcas L.) (Malpighiales: Euphorbiaceae) (Bondar 1926; Silva et al. 2008).
Thrips species and plants attacked.
Selenothrips rubrocinctus (Giard) is a key pest of Theobroma cacao L. (Malvales: Malvaceae) (cocoa) in Brazil, but it also attacks many other plant species, especially fruit crops (Lima & Zucchi 2015). Here, we report damage to Calophyllum brasiliense Cambess (Malpighiales: Calophyllaceae) (guanandi). Adults, all immature instars, and eggs were observed in greenhouses on almost all guanandi plants (Fig. 1p). Adults oviposited and fed on young leaves, especially on the underside. The damage became apparent after the leaves matured, around 2 wk after the emergence of shoots (Fig. 1q and r). As the attack proceeded, the leaves turned silver and bronze and aborted, affecting the development of the plant by reducing the photosynthetic area. Selenothrips rubrocinctus is the second species of thrips recorded as damaging guanandi in Brazil, after Danothrips trifasciatus Sakimura (Thomazini & Lima 2014), which causes symptoms (curling on the edges of new leaves, which become gnarled and brittle) that are different from those caused by S. rubrocinctus. At the same collection site, damage from S. rubrocinctus to Liquidambar styraciflua L. (Saxifragales: Altingiaceae) (sweetgum) was observed for the first time in Brazil. Specimens were collected in greenhouses and caused discoloration and necrosis of the leaves, with abundant black fecal material (Fig. 1s and t).
Caliothrips phaseoli. BRAZIL. Acre: Rio Branco (9.9772222°S, 67.8408333°W), on mint (Mentha sp.) leaves, 15-VIII-2014, 2 ♀2 (R.S. Santos col.).
Dinurothrips hookeri. BRAZIL. Acre: Rio Branco (9.9772222°S, 67.8408333°W), on mint (Mentha sp.) leaves, 15-VIII-2014, 30♀, 4♂, 5 immatures (R.S. Santos col.).
Frankliniella insularis. BRAZIL. São Paulo: Atibaia (23.0163889°S, 46.5733333°W), on rose (Rosa × grandiflora ‘Greta’, ‘Marlyse’, and ‘Hollywood’) flowers, V-2012 to VII-2012, 49♀, 4♂, 12 immatures (L. Saito col.).
Heliothrips haemorrhoidalis. BRAZIL. Piauí: Teresina (5.0891667°S, 42.8019444°W), on frangipani (Plumeria sp.) leaves, 26-VII-2012,12 ♀, 5 immatures (E.F.B. Lima col.).
Retithrips syriacus. BRAZIL. São Paulo: Piracicaba (22.7183333°S, 47.6341667-W), on rose (Rosa sp.) leaves, 7-XI-2013, 8♀, 14 immatures (E.N. Lopes col.); São Paulo: Piracicaba (22.7125000°S, 47.6286111°W), on tropical almond (Terminalia catappa) leaves, 5-XII-2013,11♀,19 immatures (E.N. Lopes col.).
Selenothrips rubrocinctus. BRAZIL. Paraná: Colombo (25.3205556°S, 49.1586111°W), on guanandi (Calophyllum brasiliense) and sweetgum (Liquidambar styraciflua) leaves, 14-X-2014, 46♀, 36 immatures (M. Thomazini col.).