Stem Borer Solutions Quiz Quiz

Assess your understanding of stem borer pests in fodder sorghum, their identification, life cycle, damage symptoms, and effective management strategies in agriculture.

1. Identifying the Causative Pest

   Which pest is primarily responsible for 'dead heart' symptoms in fodder sorghum fields?

   1. Spodoptera litura
   2. Helicoverpa armigera
   3. Chilo partellus
   4. Aphids

   Explanation: Chilo partellus, the spotted stem borer, is mainly responsible for 'dead heart' in fodder sorghum as its larvae bore into stems and damage the growing point. Helicoverpa armigera targets mainly pods or flowers, not stems. Spodoptera litura is a leaf-eating caterpillar. Aphids suck sap from leaves and do not cause dead heart symptoms.

2. Life Cycle Checkpoint

   During which stage of Chilo partellus does it cause the most damage to sorghum stems?

   1. Adult moth stage
   2. Egg stage
   3. Pupal stage
   4. Larval stage

   Explanation: Larvae of Chilo partellus bore into the stem and feed on internal tissues, causing the most severe damage. Eggs do not feed and hence cause no injury. Pupae are inactive and sheltered within the stem. Adults are moths that lay eggs but do not damage the plant directly.

3. Recognizing Damage

   Which symptom best characterizes stem borer infestation in fodder sorghum?

   1. Central leaf shoots drying while outer leaves remain green
   2. Leaves with yellow streaks
   3. Powdery mildew on leaf surfaces
   4. Small round holes in pods

   Explanation: Dead heart, where central leaf shoots dry but outer leaves stay green, is a hallmark of stem borer injury. Yellow streaks are generally signs of viral disease. Powdery mildew affects leaf surfaces but not stems. Round holes in pods are caused by pod borers, not stem borers.

4. Management Strategy

   Which integrated method is commonly recommended to manage stem borer in fodder sorghum?

   1. Early sowing and removal of infested stems
   2. Heavy irrigation only
   3. Use of chemical herbicides
   4. Planting sorghum in shaded areas

   Explanation: Early sowing avoids peak pest activity and removing affected stems reduces pest numbers, making this an integrated approach. Heavy irrigation alone does not control stem borers. Herbicides target weeds, not pests. Shaded planting isn't an effective control and might even increase borer incidence.

5. Predator Awareness

   Which natural enemy most commonly helps control Chilo partellus populations in sorghum fields?

   1. Trichogramma spp.
   2. Armyworm
   3. Rice weevil
   4. Locusts

   Explanation: Trichogramma spp. are parasitic wasps that lay eggs inside stem borer eggs, reducing their numbers naturally. Locusts and armyworms are pests themselves, not beneficials. Rice weevil infests stored grains, not field pests.