ICAR AIEEA PG Entomology 14 July 2023 Shift-1 Paper

EPN foraging strategies:

• Ambushers: Remain near the soil surface and nictate (stand upright) waiting for mobile surface-dwelling hosts (e.g., Steinernema carpocapsae).
• Cruisers: Highly mobile nematodes that actively cruise through soil pores responding to host volatiles and $\text{CO}_2$ cues to infect sedentary hosts deeper in the soil profile (e.g., Steinernema glaseri and Heterorhabditis bacteriophora).
• Intermediates: Exhibit both ambushing and cruising behaviors (e.g., Steinernema feltiae).

Integrated management of Meloidogyne enterolobii in guava orchards:

• Chemical nematicides (e.g., fluopyram, carbofuran) provide rapid curative suppressive action.
• Biological control agents (such as Purpureocillium lilacinum and Trichoderma harzianum) actively parasitize nematode egg masses and juveniles.
• The primary and most critical preventive barrier is planting certified, clean, nematode-free saplings in uninfested soil to prevent introduction of this destructive nematode into new orchards.

Quarantine status of nematodes in India:

• Bursaphelenchus xylophilus (pine wood nematode, the causal agent of pine wilt disease) is a regulated high-risk quarantine pest in India prohibited under the Plant Quarantine (Regulation of Import into India) Order.
• Heterodera zeae (corn cyst nematode), Heterodera avenae (cereal cyst nematode), and Pratylenchus zeae (root-lesion nematode) are already established domestic pests within India.