Gerris spinolae Lethierry and Severin (Hemiptera: Gerridae) and Brachydeutera longipes Hendel (Diptera: Ephydridae): Two Effective Insect Bioindicators to Monitor Pollution in Some Tropical Freshwater Ponds under Anthropogenic Stress

Table 1

Physical, chemical, and biological parameters of water quality in the four ponds (Botanical garden—control; Kurukshetra, Sankuldhara and Durgakund—anthropogenically stressed) located in different parts of Varanasi, India.

Water parameters	In Botanical garden pond	In anthropogenically disturbed ponds
	(Control)	Kurukshetra	Sankuldhara	Durgakund
Temperature (°C)(Mean ± SEM )	16.19 ± 2	16.35 ± 2.01^ns	16.53 ± 2.02^ns	16.67 ± 2.02^ns
pH (Mean ± SEM)	6.89 ± 0.11	9.16 ± 0.015***	8.85 ± 0.013***	6.402 ± 0.016***
Dissolved oxygen (mg/L)(Mean ± SEM )	8.84 ± 0.50	7.61 ± 0.42***	4.98 ± 0.33***	4.13 ± 0.45***
Free CO2 conc. (mg/L)(Mean ± SEM)	1.8 ± 0.25	1.07 ± 0.16^ns	5.18 ± 0.38***	5.38 ± 0.5***
BOD (mg/L)(Mean ± SEM)	5.68 ± 0.42	6.49 ± 0.47***	8.03 ± 0.53***	8.47 ± 0.62***
Phosphate ion conc. (mg/L)(Mean ± SEM)	0.16 ± 0.02	0.43 ± 0.05***	0.47 ± 0.05***	0.63 ± 0.09***
Dry weight of algae,Microcystis sp.(g/sq m)(Mean ± SEM)	00.00	10.81 ± 0.35***	10.94 ± 0.29***	30.58 ± 0.36***

Where *𝑃<0.05, **𝑃<0.01, and ***𝑃<0.001, ns—not significant.