Do primary and secondary host plants affect aphid- parasitoid interactions in fruit orchards?

Area of Science:

• Agricultural Entomology
• Ecology
• Biological Pest Control

Background:

• Fruit orchards host complex tritrophic interactions between aphids, their parasitoids, and host plants.
• Understanding these interactions is crucial for developing effective biological control strategies.
• The role of primary host plants (PHP) versus secondary host plants (SHP) in mediating these interactions remains understudied.

Purpose of the Study:

• To investigate the influence of primary (PHP) and secondary host plants (SHP) on aphid-parasitoid interactions in Turkish fruit orchards.
• To assess the impact of host plant type on species richness and biodiversity of aphids and parasitoids.
• To document new aphid-parasitoid-host plant associations for Europe and Turkey.

Main Methods:

• Field surveys were conducted in northwest Turkey during spring and summer of 2020 and 2021.
• Aphids and their parasitoids were collected from 22 primary and secondary host plants in fruit orchards.
• 16 parasitoid species (subfamily Aphidiinae) and 25 aphid species were identified, documenting 67 tritrophic interactions.

Main Results:

• Species richness and biodiversity indices for both aphids and parasitoids were significantly higher on secondary host plants (SHP) compared to primary host plants (PHP).
• Aphid-parasitoid interactions exhibited greater diversity on SHP than on PHP.
• New records of aphid-parasitoid-host plant associations were identified for Europe and Turkey.

Conclusions:

• Secondary host plants play a more significant role in supporting diverse aphid and parasitoid communities in fruit orchards than primary host plants.
• The findings underscore the importance of considering SHP in pest management and conservation strategies within agricultural landscapes.
• This study contributes valuable data on tritrophic interactions and expands the known geographical distribution of several aphid parasitoid species.