Thermal requirements and estimated number of generations of Neopamera bilobata (Say) in strawberry-producing regions of Brazil

Abstract

The thermal threshold and thermal requirements of Neopamera bilobata were determined, and the number of generations that this species may produce in the main strawberry-producing regions of Brazil was estimated. In a climate chamber (70±10% RH and 12h photophase) at 16, 19, 22, 25, 28, or 30±1°C, the development of 120 eggs was monitored until the adult stage, at each temperature. Nymphs were maintained in individual cages and fed on strawberry fruits of the cultivar Aromas. The mean duration and viability of the egg and nymph stages were calculated by estimating the lower and upper developmental thresholds and the thermal constant, and this information was used to estimate the number of generations per year in different strawberry-producing regions of Brazil. The egg-to-adult duration decreased as temperatures increased, up to 28°C (93.4, 83.2, 43.9, and 31.4 days at 19, 22, 25, and 28°C, respectively). Viability of nymphs was highest between 22 and 28°C. At 30°C, the egg-to-adult duration increased (36 days), while the viability decreased (11.11%). The lower egg-to-adult developmental threshold was 15.2°C and the thermal constant was 418.4 degree-days. Calculating the number of generations indicated that the largest number (5.1 generations yr-1) was obtained for the municipality of Jaboti, Paraná, and the smallest for Caxias do Sul, Rio Grande do Sul (1.9 generations yr-1). Our findings demonstrated that important strawberry-producing regions in Brazil are suitable for the development of N. bilobata.

Neopamera bilobata (Hemiptera: Rhyparochromidae), a strawberry pest, arrives in Santa Catarina state, Brazil

“…Regarding the environmental condition, N. bilobata is absent from places with temperatures up to 16°C, and its optimal development range is between 22 and 28°C, but if it exceeds 30°C, there is a reduction in viability of the life cycle of the species (Kuhn et al, 2018). The justification of the present report is the occurrence of the species in a region of often low temperatures, such as the region of Contestado Catarinense, which has an average annual temperature of 14.7°C.…”

“…The species is polyphagous, occasionally reported in tobacco crops and fig seeds (Faúndez, 2022), and despite feeding on strawberry leaves, nymphs only complete their development by feeding on unripe or ripe fruit, causing it to stop growing, stiffening, and drying out when in the early stages of infestation. In case of high infestation, the crown of the plant is also attacked, which causes wilting, leading to production loss (Kuhn et al, 2018).…”

“…Eggs of this insect are elongated and yellow and are usually deposited on fruits or the sepals, neck, or crown of the plant (Kuhn et al, 2018). The nymphal stage goes through five instars.…”

Chinese chives and garlic in intercropping in strawberry high tunnels for Neopamera bilobata Say (Hemiptera: Rhyparochromidae) control

“…High N. bilobata populations are mostly seen during the warm periods between November and January. Based on N. bilobata thermal requirements studies and historical mean temperatures, it is estimated that until five generations of this insect per year may be achieved in Parana State (Kuhn et al , 2018). In Minas Gerais State, Brazil, a study shows that N. bilobata was the most abundant arthropod species associated with strawberry (De Melo, 2017).…”

Mortalidade e comportamento de Neopamera bilobata (Hemiptera: Rhyparochromidae) submetido ao inseticida à base de Sophora flavescens

“…Neopamera bilobata was first reported in strawberry in studies on the biology and characterization of injuries to the plant, mainly to the berry (deformation) in different stages of development (Kuhn et al, 2014b). Other studies addressing biological parameters have been published (Kuhn et al, 2018), but the challenge of controlling this pest has not yet been overcome.…”