Numbers
4 spp. in 2 subgenera in our area
(1); 3 subgenera total
(2)
H. (H.) ensifer s.FL & the Neotropics
H. (H.) insularis s.AZ, s.TX, FL & Mesoamerica
H. (H.) triangularis: Canada (BC‒QC) to Mexico
H. (D.) ovatus: e.NA (QC‒FL to IA‒TX); Mexico
Size
the largest members of the family, >30 mm (our spp. up to 40 mm, extralimital spp. up to ~50 mm)
(2)(3)Habitat
stagnant/slow waters; prefer deeper water (weedy ponds, deep drainage ditches)
(2)Life Cycle
Female deposits up to 140 eggs in cocoon-like case with a "mast". Pupation in moist soil. 1‒2 generations per year. Some adults overwinter under leaf litter. Others may remain under ice and stay active all winter. Lifespan may exceed one year.
Remarks
The subgenus Dibolocelus in Mexico was recently revised, with 5 additional spp. (other than H. ovatus) recorded along the Gulf Coast in Mexico and one in Cuba. Some of these species may be eventually discovered in so.TX or FL. (Arce-Pérez et al. 2021)
Print References
Arce-Pérez R., Arriaga-Varela E., Novelo-Gutiérrez R., Navarrete-Heredia J.L. (2021) Giant water scavenger beetles
Hydrophilus subgenus
Dibolocelus (Coleoptera: Hydrophilidae) from Mexico with description of two new species. Zootaxa 5027: 387–407.
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