Population dynamics of Palpita forficifera Munroe, 1959 (Lepidoptera: Crambidae) and associated parasitoids in olive orchards

Abstract

Abstract Palpita forficifera Munroe, 1959 (Lepidoptera: Crambidae) is the main pest of the olive tree (Olea europaea L., Oleaceae) in Brazil and its management has been difficult, as there are few products recommended for its control. This study aimed to evaluate the population dynamics of P. forficifera and the entomofauna of parasitoid eggs and larvae in three olive orchards under different cultivation systems, in Rio Grande do Sul state, Brazil. The study was carried out from October to May, in the 2017/18 and 2018/19 harvests, in olive orchards of different cultivars in the municipalities of Pelotas and Rio Grande, state of Rio Grande do Sul, Brazil. Population dynamics of P. forficifera varied according to the agricultural season, the months sampled, and the orchards (sites) evaluated. The highest infestation reached around 60% of the shoots in some months, depending on the orchard evaluated. During the pest infestation period, the occurrence of the egg parasitoid Trichogramma foersteri Takahashi, 2021 (Hymenoptera: Trichogrammatidae) was observed along with three larval parasitoids belonging to the genera Dolichogenidea Viereck, 1911, Hymenochaonia Dalla Torre, 1898 (Hymenoptera: Braconidae) and Temelucha Förster, 1869 (Hymenoptera: Ichneumonidae). Temelucha hilux Gauld, 2000 is recorded for the first time in association with a host, and its distribution in the country is extended to the southern region, from Brazil. Due to the scarcity of information on pest management, the natural occurrence of natural enemies in crops is of paramount importance in helping to manage P. forficifera in the field. The population dynamics of P. forficifera is also influenced by the parasitoid community, made up of at least four species of parasitic Hymenoptera. Therefore, strategies aimed at managing P. forficifera must be well developed in order to maintain and increase natural biological control in the field.

Keywords

• Braconidae
• Ichneumonidae
• olive caterpillar
• Trichogrammatidae