Project properties
Title Unravelling interactions between spiders and mealybugs (in Spain)
Group Entomology, Laboratory of
Project type internship
Credits 24-36
Supervisor(s) IVIA: Dr. Maite Fernández de Bobadilla and Dr. Alejandro Tena
WUR: Dr. Martine Kos
Examiner(s) Prof. dr. M. Dicke
Contact info IVIA: Dr. Maite Fernández de Bobadilla (maria.fernandezdebobadilla@gmail.com)
WUR: Dr. Martine Kos (martine.kos@wur.nl).
Begin date 2024/02/01
End date 2025/12/31
Description Start and end date: Projects can start any time from beginning of February 2024 and finish at December 2025.

Internship at Plant Protection- Entomology at Instituto Valenciano de Investigaciones Agrarias (IVIA) Valencia (Spain)

The FAO estimates that annually 40 percent of global crop production is lost to pests. One of the most difficult-to-manage and damaging pests in agriculture are hemipterans. such as aphids, whiteflies, mealybugs, psyllids, and soft scales. All these hemipterans have in common that they feed from the phloem sap and excrete honeydew rich in carbohydrates. Historically, honeydew has been viewed only as a problem in agriculture because it is the growth medium of sooty moulds that reduce the photosynthetic capacity of the plant and cause aesthetic damage to the fruits. However, this excretion product is also the most abundant and accessible source of carbohydrates for parasitoids and predators in many agroecosystems and, thus, it mediates many interactions that affect biological control.
Spiders are one of the more diverse arthropod taxa, naturally occurring ubiquitous predators in most ecosystems. Due to their high diversity, spiders encompass many guilds or functional groups (i.e., groups of species using the same class of resources in a similar way) according to their hunting strategies. Spiders are the most widespread of the predators, often they exist in any place, in the agricultural ecosystem where they are beneficial in the reduction of the population density of the pests. Thus, they can play an important role in the control of the pests. These characteristics led to considering spiders as potentially successful natural enemies.
Spiders are considered exclusively carnivores. Nonetheless, researchers at IVIA spotted spiders associated with colonies of honeydew producers (specially mealybugs). Interestingly, the spiders build the silk web around the colony of the mealybugs to attract honeydew feeder (including beneficial insects such as parasitoids and pollinators) and prey them. The goal of this line of research is to investigate the potential beneficial interaction between spiders and mealybugs. In your MSc thesis you may focus on the following points depending on your interests:
i) To investigate if the spider benefits from the interaction with the mealybug (i.e., increased performance, increased prey attraction).
ii) To investigate if the mealybug benefits from the interaction with the spider (i.e., increased protection against natural enemies, reduced parasitism, and predation)
iii) To determinate if the mutualistic relationship shifts towards a negative interaction in case of absence of prey for the spider.

Study system: mealybugs (Delottococcus aberiae or Planococcus citri), true spider (Kochiura sp.), mealybugs’ natural enemies (Anagyrus sp.).
Used skills behavioral ecology, preference assays, parasitism assessment, biological control, trophic interactions, experimental design, spider-mealybugs mutualism.
Requirements ENT-30806 Fundamental and Applied Aspects of the Biology of Insects. For MBI students the requirement is that they have followed the two courses of their MBI specialization.