Mosquitocidal Susceptibility and Non-Target Effects of Tricholoma equestre Mushroom (Agaricomycetes) on the Immature Stages of Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus.

The worldwide scientific community is well aware that mosquitoes are the sole agents responsible for transmitting various dreadful diseases and critical illnesses caused by vector-borne pathogens. The primary objective of this current research was to evaluate the effectiveness of methanol extract from Tricholoma equestre mushroom in controlling the early life stages of Culex quinquefasciatus Say, Anopheles stephensi Liston, and Aedes aegypti (Linnaeus in Hasselquist) mosquitoes. The larvae, pupae and eggs of these mosquitoes were exposed to four different concentrations (62.5 to 500 ppm). After 120 h of treatment, the methanol extract of T. equestre exhibited ovicidal activity ranging from 66% to 80% against the eggs of the treated mosquitoes. It also demonstrated promising larvicidal and pupicidal activity with LC50 values of 216-300 and 230-309 ppm against the early life stages of all three mosquito species. Extensive toxicity studies revealed that the methanol extract from T. equestre had no harmful effects on non-target organisms. The suitability index (SI) or predator safety factor (PSF) indicated that the methanol extract did not harm Poecilia reticulata Peters 1859, (predatory fish), Gambusia affinis S. F. Baird & Girard 1853, dragonfly nymph and Diplonychus indicus Venkatesan & Rao 1871 (water-bug). Gas chromatography-mass spectrometry (GCMS) analysis identified key compounds, including 3-butenenitrile, 2-methyl-(25.319%); 1-butanol, 2-nitro-(18.87%) and oxalic acid, heptyl propyl ester (21.82%) which may be responsible for the observed activity. Furthermore, the formulation based on the methanol extract demonstrated similar effectiveness against all treated mosquitoes at the laboratory level and was found to be non-toxic to mosquito predators. This groundbreaking research represents the first confirmation that methanol extract from T. equestre could be effectively employed in preventing mosquito-borne diseases through mosquito population control programs.

Chemical composition and mosquitocidal properties of essential oil from Indian indigenous plants Ocimum tenuiflorum L. and Ocimum americanum L. against three vector mosquitoes.

Mosquitoes stand out as the most perilous and impactful vectors on a global scale, transmitting a multitude of infectious diseases to both humans and other animals. The primary objective of the current research was to assess the effectiveness of EOs from Ocimum tenuiflorum L. and Ocimum americanum L. in controlling Anopheles stephensi Liston. Culex quinquefasciatus Say and Aedes aegypti L. mosquitoes. The larvae, pupae and eggs of the mosquitoes were exposed to four different concentrations (6.25-50 ppm). The tested EOs resulted in >99-100 % mortality at 120 h for the eggs of all examined mosquito species. It also showed robust larvicidal and pupicidal activity with LC50 and LC90 values of 17-39, 23-60 ppm and 46-220, and 73-412 ppm against Aedes, Culex and Anopheles mosquito species, respectively, at 24 h of treatment. The Suitability Index or Predator Safety Factor demonstrated that the EOs extracted from O. tenuiflorum L. and O. americanum L. did not cause harm to P. reticulata, D. indicus (water bug), G. affinis and nymph (dragonfly). GC-MS analysis identified the major probable constituents of the oil, including Phenol, 2-Methoxy-4-(1-Propenyl)- (28.29 %); 1-Methyl-3-(1'-Methylcyclopropyl) Cyclopentene (46.46 %); (E,E,E)-3,7,11,15-Tetramethylhexadeca-1,3,6,10,14-Pentaene (18.91 %) and 1,3-Isobenzofurandione, 3a,4,7,7a-Tetrahydro-4,7-Dimethyl (33.02 %). These constituents may play a significant role in the mosquitocidal activity of the oil. The same results were identified in the formulation prepared from the EOs. This marks the first report confirming the successful utilization of EOs derived from O. tenuiflorum L. and O. americanum L. in mosquito population control initiatives.

Mosquitocidal Activity of the Pale Brittle Stem Mushroom, Psathyrella candolleana (Agaricomycetes), against Three Vector Mosquitoes.

The aim of the present study was to screen for mosquito larvicidal activity of methanol extract of a wild mushroom Psathyrella candolleana against Culex quinquefasciatus, Aedes aegypti, and Anopheles stephensi. Larvae and eggs were exposed to four different concentrations (62.5, 125, 250, and 500 ppm) and mortality was assessed 24 and 120 h after treatment. The LC50 and LC90 values of the extract were calculated. Methanol crude extract of P. candolleana showed good larvicidal activity against the third instar larvae of Cx. quinquefasciatus with LC50 and LC90 values of 166.713 and 259.17 ppm, respectively, after 24 h of exposure. No larvicidal activity was observed against Ae. aegypti and An. stephensi. The methanol extract of P. candolleana presented 88% ovicidal activity against Cx. quinquefasciatus at 500 ppm concentration 120 h after treatment. The active methanol extract was tested for toxicity against non-target organism and found was to have no toxicity. Histopathological studies of the treated larvae revealed serious damages to the midgut cells. The mushroom species was confirmed by 5.8S rRNA sequence and phylogenetic tree was constructed. These results suggest that the methanol extract of P. candolleana could be used in Cx. quinquefasciatus control programs as a new eco-friendly larvicide.

Larvicidal, Ovicidal, and Histopathological Effects of the Sulphur Polypore Mushroom, Laetiporus sulphureus (Agaricomycetes), Collected from Tamil Nadu, India against Mosquitoes.

This study was conducted to determine the mosquitocidal activity of 6 species of higher Basidiomycetes collected from various places in the state of Tamil Nadu, India. The mushrooms were identified using MycoKey MMI software. We used morphological characteristics such as size, color, height, width (of the cap, lamellae, stipe, and fruiting body), spore deposits, and the presence or absence of ring to identify species. Eggs and larvae of Culex quinquefasciatus and Anopheles stephensi were exposed to various concentrations (62.5, 125.0, 250.0, and 500.0 ppm) of extracts from the 6 mushrooms. The extracts were dissolved in dimethyl sulfoxide. Among the 6 mushrooms, the methanol extract of Laetiporus sulphureus showed high toxicity toward mosquitoes at different life stages, with 96% larvicidal activity against A. stephensi and 76% activity against C. quinquefasciatus. After 24 hours, we found half-maximal lethal concentrations of 155.862 ppm for A. stephensi and 227.225 ppm for C. quinquefasciatus, and 90% lethal concentrations of 424.128 ppm for A. stephensi and 1011.663 ppm for C. quinquefasciatus. The extracts also showed strong ovicidal activity against mosquito eggs: 100% activity against A. stephensi and 91% activity against C. quinquefasciatus were observed at an extract concentration of 500 ppm 120 hours after treatment. The methanol extract of L. sulphureus was tested for toxicity against a nontarget organism, but we found none. Histopathological studies of the treated larvae revealed serious damage to cells in the midgut. These results suggest that the methanol extract of L. sulphureus is a good natural source for controlling mosquitoes.