# Availability, Accessibility, and Suitability of Native Flowers from Central Chile to Mastrus ridens, a Parasitoid of Codling Moth

## TL;DR

This study identifies native Chilean flowers that can support a parasitoid wasp used to control codling moths, promoting both pest control and biodiversity.

## Contribution

The study evaluates native Chilean flowers for their suitability in supporting Mastrus ridens, a parasitoid of codling moth, through nectar availability, accessibility, and longevity.

## Key findings

- Four native Chilean species provided easily accessible nectar for Mastrus ridens.
- Teucrium bicolor and Sphaeralcea obtusiloba extended parasitoid longevity when used as cut flowers.
- Using native flowering species in agroecosystems can enhance biological control and biodiversity conservation.

## Abstract

Non-crop vegetation can be used to conserve pest natural enemies by providing complementary food, and by using native plants, biodiversity conservation in agricultural areas can be promoted. The potential for nectar provision of 13 flowering species native to Chile, and two introduced, was studied considering Mastrus ridens, a natural enemy of the codling moth. Nectar availability was studied by looking at flowering periods, accessibility by contrasting the size of the flowers and head of the insect, and suitability by the longevity when exposed to nectar solutions or cut flowers. Most species had long flowering periods, potentially making nectar available when insects are active, but they differed in nectar accessibility and profitability. Of the 13 native species, nectar was easily accessible for M. ridens in only four species. Parasitoid longevity did not increase with nectar solutions, but they lived longer with cut flowers of two native species, Teucrium bicolor and Sphaeralcea obtusiloba, and one introduced, Fagopyrum esculentum, making them candidates for M. ridens conservation. In conclusion, using suitable native flowering species in agroecosystems can improve codling moth control and biodiversity conservation.

Habitat manipulation through non-crop vegetation management is a strategy in conservation biological control, and using native plants is attractive because they can also help in biodiversity conservation. The potential for nectar provision of 13 flowering species native to Chile, and two introduced, was evaluated considering Mastrus ridens (Hymenoptera: Braconidae). Nectar availability was studied through flower phenology, accessibility through flower and parasitoid morphology, and suitability through longevity when exposed to nectar solutions or cut flowers. Most species had long flowering periods, potentially making nectar available when adults are active, but they differed in nectar accessibility and profitability. Of the 13 native species, nectar was easily accessible for M. ridens in Cistanthe grandiflora, Sphaeralcea obtusiloba, Andeimalva chilensis, and Lycium chilense. None of the nine native species tested with nectar solutions increased longevity, but with cut flowers, parasitoids lived longer with the natives Teucrium bicolor and S. obtusiloba, and the introduced Fagopyrum esculentum, making them candidates for M. ridens conservation. Females lived longer with cut flowers of T. bicolor and S. obtusiloba than with their nectar solutions. In conclusion, using the native flowering species Teucrium bicolor and Sphaeralcea obtusiloba in agroecosystems can serve biological control and biodiversity conservation.