This document discusses the symptoms caused by different types of entomopathogenic microorganisms, including bacteria, viruses, fungi, nematodes, protozoa, and rickettsiae. It describes how these pathogens affect insects through reduced feeding and activity, disintegration of tissues, production of spores or hyphae on the exterior of the insect, and other symptoms. The document also lists desirable attributes for entomopathogens used as biopesticides, such as high virulence, host specificity, safety to non-target organisms, and cost-effective mass production.

1. ELEC 230 (2+1):BIOPESTICIDES AND
BIO FERTILIZERS
Course In-Charge
Mr.S.Srinivasnaik
Assistant Professor
Department of Entomology
Lecture No.5
VIRULENCE, PATHOGENESITY AND SYMPTOMS OF
ENTOMOPATHOGENS

2. ENTOMOPATHOGENIC BACTERIA
•Reduced feeding and reduced activity of insect
•Fluid discharge from mouth and anus
•Body becomes dark/black and finally septicaemia (Blood
poisoning)
•Excretory system is affected, body cells get disintegrated
•Non coordination of nervous system
•Milky disease caused by Bacillus popilliae in Scarabaeidae
family insects viz., Popillia japonica (Japanese beetle). The
blood of the insect becomes white.
•Virulence: 2-3 days the insect get killed

3. ENTOMOPATHOGENIC VIRUS
•Dull in colour
•Feeding rate is reduced
•Larvae become pinkish white in the ventral side due to the
accumulation of polyhedra
•Larvae become flaccid, fragile, rupture,
•Diseased larvae hangs upside down known as
wipfelkrankheit/tree top symptom/caterpillar wilt
•Virulence:4-6 days

4. ENTOMOPATHOGENIC FUNGI
1. Beauveria bassiana
•Soft and breakable
•Dried and giving milky liquid
2. Nomouraea rileyi
•Yellow to brown spots on the integument
•Swelling of posterior abdominal segments
•Covered with pale green spores
3. Metarhizium anisopliae
Mummified
Hard
Covered olive green powdery mass of spores
4. Verticillium lecanii
Mummified
Hard
Covered filamentous white hyphae

5. ENTOMOPATHOGENIC NEMATODE
Reduced appetite, activity and disintegrated tissues of
different organs

6. ENTOMOPATHOGENIC PROTOZOA
Chronic effect, prolong the larval life and expose to the predators
and parasitoids and body becomes soft and breakable. Virulence
is 30 days

7. ENTOMOPATHOGENICRICKETTSIAE
•Lorsch disease: Rickettsiae melolanthe on lamellicorn beetle
•Blue disease: Rickettsiae popilliae on Japanese beetle, Popillia
japonica
Virulence: debilitative pathogen: it kills the insect in 30-90 days
indirectly

8. ENTOMOPATHOGENICRICKETTSIAE
Stomach poisons: Bacteria and Viruses
Contact poisons: Fungi
Contact and stomach: Nematode, Protozoa and Rickettsiae
Desirable attributes of entomopathogens
•Pathogen should be highly virulent able to cause disease in short
period
•It should have host specificity
•Cost effective and economical for its mass production
•Harmless to other forms of life (Safe to non target organisms)
•Rapid prevention of pest feeding