Comparative morphology of the larvae of the palm weevils Dynamis borassi (Fabricius) and Rhynchophorus palmarum (Linnaeus) (Curculionidae: Dryophthorinae): Two major pests of peach palms in the Neotropics

The morphology of the larvae of Dynamis borassi (Fabricius) and Rhynchophorus palmarum (Linnaeus) was compared, described and illustrated. A complete definition of subtribe Rhynchophorina at the larval stage was elaborated, based on mature and submature larvae, and characters of the first instar larvae are provided for the first time. Diagnostic characters to distinguish the larvae of D. borassi and R. palmarum are mainly from the epipharynx and maxillae, but the abdominal terminal plate also provides differential features that can aid in the identification. The characterization of both species at the larval stage is expected to be useful in the implementation of new control strategies in palm plantations in South America. For practical reasons, a comparative table is appended in Spanish to serve as a quick diagnostic guide for species identification.

Comparative morphology of the larvae of the palm weevils Dynamis borassi (Fabricius) and Rhynchophorus palmarum (Linnaeus) (Curculionidae: Dryophthorinae): Two major pests of peach palms in the Neotropics

The morphology of the larvae of Dynamis borassi (Fabricius) and Rhynchophorus palmarum (Linnaeus) was compared, described and illustrated. A complete definition of subtribe Rhynchophorina at the larval stage was elaborated, based on mature and submature larvae, and characters of the first instar larvae are provided for the first time. Diagnostic characters to distinguish the larvae of D. borassi and R. palmarum are mainly from the epipharynx and maxillae, but the abdominal terminal plate also provides differential features that can aid in the identification. The characterization of both species at the larval stage is expected to be useful in the implementation of new control strategies in palm plantations in South America. For practical reasons, a comparative table is appended in Spanish to serve as a quick diagnostic guide for species identification.(AU)

Biologia de Tetranychus mexicanus (McGregor) (Acari: Tetranychidae) em folhas de Pupunha (Bactris gasipaes Kunth) / Life-history of the Tetranychus mexicanus (McGregor) (Acari: Tetranychidae) on leaves of the Pupunha or Peach-palm (Bactris gasipaes Kunth)

O objetivo deste trabalho foi avaliar a biologia do ácaro Tetranychus mexicanus (McGregor) criado em folíolos de Bactris gasipaes Kunth (pupunha). O ensaio foi conduzido em condições de laboratório com temperatura variando entre 25°C + 1°C, umidade relativa entre 60,0% ± 10,0% e fotofase de 14h. O período decorrido de ovo a adulto foi de 13,0 dias para machos e de 13,6 dias para fêmeas, com sobrevivência de 59,3%. A proporção sexual foi de aproximadamente 4,7 fêmeas para cada macho. Depois de um período de pré-oviposição de 2,0 dias, as fêmeas passaram por um período médio de oviposição de 12,1 dias, com número médio de ovos por fêmea por dia de 0,82. A longevidade foi de 7,1 dias para machos e 16,7 dias para fêmeas. A razão intrínseca de aumento (r) foi de 0,06, a razão finita de aumento (2) de 1,06 indivíduos por fêmea por dia, o tempo médio de uma geração (T) de 21,6 dias e a taxa líquida de reprodução (Ro) de 3,7.

The objective of the work was to evaluate the biology of the mite called Tetranychus mexicanus (McGregor), reared on leaflets of Bactris gasipaes Kunth (peach-palm). The test was carried out under laboratory conditions at a temperature of 25°C ± 1°C, relative humidity of 60,0% ± 10,0% and photophase of 14 hours. The period of development from egg to adult was 13 days for males and 13.6 days for females, with a survival rate of 59.3%. The sex ratio was approx. 4.7 females per male. After a pre-oviposition period of 2 days, the females underwent a period of oviposition, on average, of 12.1 days, with 0.82 eggs per female per day. Longevity was 7.1 days for males and 16.7 days for females. The intrinsic rate of increase (r) was 0.06, the finite rate of increase (2) 1.06 individuals per female per day, the mean generation time (T) 21.6 days and net reproductive rate (Ro) 3.7.