Evaluation of Conidia-Dust Formulation of the Entomopathogenic Fungus, Metarhizium anisopliae to Biocontrol the Brown-Banded Cockroach, Supella longipalpa F.
BACKGROUND
The brown-banded cockroach Supella longipalpa (F.) as a mechanical vector of pathogens and source of allergens has recently become widespread in the city of Ahvaz, southwestern Iran.


OBJECTIVE
This research was done to evaluate the efficacy of a dust-formulation of Metarhizium anisopliae isolate IRAN 437C, as a common entomopathogenous fungus, against S. longipalpa.


METHODS
Conidia dust-formulations of M. anisopliae were prepared in proportions of 1%, 5%, 10%, 25%, 50% and 100% with bad wheat flour as the carrier. Cockroaches were exposed to surfaces treated with 1.5 mg/cm(2) of the formulations under laboratory and semi-field conditions.


RESULTS
Cockroach mortality rates increased and survival times (ST50) decreased with an increased proportion of conidia from 1% to 100% but records taken for mortality and survival time from proportions of 25%, 50% and 100% were not significantly different. The mortality rates reached 100% and 90-100% in adults and nymphs, respectively on the seventh day. The lowest ST50 was related to the proportion of 100% (3 days). Probit analysis indicated LD50 and LD90 values of 1.7 × 10(6) and 1.7 × 10(7) conidia/cm(2) for adults and these values changed to 4.5 × 10(6) and 2.9 × 10(7) for third and fourth instar nymphs at three days post exposure. Proportion of 25% caused mortality rates of 87%, 81% and 73% in adult, adult & nymph and nymph populations, respectively at four days after exposure under room conditions.


CONCLUSIONS
Conidia dust-formulation of M. anospliae isolate IRAN 437C could present a promising alternative to control the brown-banded cockroach.
Department of Medical Entomology and Vector Control, School of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
Mona
M
Sharififard
Department of Plant Protection, College of Agiculture, Chamran Univercity, Ahvaz, IR Iran.
Mohammad Saeed
MS
Mossadegh
Department of Medical Entomology and Vector Control, School of Health and Infectious and Tropical Disease Research Centre, Ahvaz Jundishapur University Medical Sciences, Ahvaz, IR Iran.
Babak
B
Vazirianzadeh
Department of Statics and Epidemiology, School of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
Seyed Mahmood
SM
Latifi
Biological Control; Metarhizium anisopliae; Supella Longipalpa