Identification and Distribution of \u3ci\u3eBaetisca\u3c/i\u3e Nymphs (Ephemeroptera: Baetiscidae) in Wisconsin

Nymphs of three species of Baetisca (Ephemeroptera: Baetiscidae) have been collected in Wisconsin. Baetisca laurentina was most abundant. occurring in a wide variety of streams and occasionally in impoundments. Baetisca obesa was uncommon and occured only in two large rivers, while B. lacustris was somewhat more common and inhabited medium to streams. Except for a few nymphs of B. lacustris that were collected from Green Bay on Lake Michigan, no Baetisca nymphs were found within 100 km of Lake Michigan

New Records of Odonata from Wisconsin

Excerpt: In 1967 Mary Davis Ries published a list of 117 species of Odonata known to occur in Wisconsin, and later (1969) reported details of the distribution of species new to the state list. Collections from the Pine-Popple River in northeastern Wisconsin (Hilsenhoff 1972) added four more species to the list. Five additional Wisconsin records are reported below as the result of occasional collections made throughout the state

Aquatic Hemiptera of Wisconsin

About 59,000 aquatic Hemiptera were collected in Wisconsin, most of them in the last 15 years. These include three species of Belostomatidae, 48 species of Corixidae, one species of Naucoridae, four species of Nepidae, nine species of Notonectidae, and one species of Pleidae. The riparian Gelastocoris oculatus was also found. Species keys for adults are provided along with notes on identification, habitat, biology, distribution, and abundance. Most species reached peak abundance in late summer and autumn and overwintered as adults, but seven species apparently overwintered as eggs. Most lentic species flew to streams or larger len tic habitats to overwinter. Populations of all species declined rapidly after mating and oviposition in the spring

Dytiscidae and Noteridae of Wisconsin (Coleoptera). II. Distribution, Habitat, Life Cycle, and Identification of Species of Dytiscinae

Twenty-one species of Dytiscinae were collected in Wisconsin over the past 30 years, including three species of Acilius, one species of Cybister, eight species of Dytiscus, five species of Graphoderus, two species of Hydaticus, and two species of Thermonectus. Species keys are provided for adults, and except for Dytiscus and Cybister, keys are also provided for larvae. Based on a study of 13,236 adults and 854 larvae, information on the distribution and abundance of each species in Wisconsin is provided along with notes on their habitat, life cycle, and identification

Gyrinidae of Wisconsin, With a Key to Adults of Both Sexes and Notes on Distribution and Habitat

More than 25,000 adult gyrinids that include 24 species were studied from all areas of Wisconsin. Dineutus discolor, Gyrinus aeneolus, G. analis, G. bifarius, and G. marginellus are lotic; D. assimilis, G. aquiris, G. confinis, and G. dichrous apparently breed in both lotie and lentic habitats; and the remaining species probably breed primarily in deep ponds or littoral areas of lakes and impoundments. Most collections were from streams in late summer and autumn because adults of almost all lentic species fly to streams to overwinter and these overwintering aggregations were easily collected. A key to adults of Wisconsin species was developed, and by using the gonocoxae and secondary sexual characters, females can be identified as accurately as males

Dytiscidae and Noteridae of Wisconsin (Coleoptera). V. Distribution, Habitat, Life Cycle, and Identification of Species of Hydroporinae, Except \u3ci\u3eHydroporus\u3c/i\u3e Clairville Sensu Lato

Thirty species in 11 genera of Hydroporinae were collected in Wisconsin over the past 32 years, excluding those in Hydorporus s.l. Fourteen species of Hygrotus were found; other genera were represented by one to four species. Species keys and notes on identification are provided for adults of all species that occur or may occur in Wisconsin. Information on distribution and abundance in Wisconsin, habitat, and life cycle is provided for each species based on a study of 34,628 adults. Life cycles were predominantly univoltine, with adults overwintering and larvae completing development from late spring to late summer, depending on the species. Most adults apparently overwinter in aquatic habitats, except those of Laccornis and Hygrotus compar, which probably overwinter in terrestrial habitats

An Improved Biotic Index of Organic Stream Pollution

Major improvements were made in using a biotic index of the arthropod fauna to evaluate organic stream pollution. All tolerance values were reevaluated, many were changed, and the scale for tolerance values was expanded to 0-10 to provide greater precision. Keys to larvae of Ceratopsyche have been developed and tolerance values for species in this important genus are provided. Sorting of samples in the laboratory instead of in the field is recommended, and directions for processing and evaluating samples are included

Dytiscidae and Noteridae of Wisconsin (Coleoptera). VI. Distribution, Habitat, Life Cycle, and Identification of Species of \u3ci\u3eHydroporus\u3c/i\u3e Clairville Sensu Lato (Hydroporinae)

Thirty-four species of Hydroporus s.l. were collected in Wisconsin over the past 32 years, including 20 of Hydroporus s.s., 7 of Neoporus, 4 of Hydroporus oblitus-group, 2 of Heterosternuta, and 1 of Sanfilippodytes. Species keys and notes on identification are provided for adults of species that occur or may occur in Wisconsin. Information on distribution and abundance in Wisconsin, habitat, and life cycle is provided for each species based on a study of 27,310 adults. Life cycles were predominantly univoltine, with adults overwintering and larvae completing development from late spring to late summer, depending on the species. Most adults apparently overwinter in aquatic habitats, but several species of Hydroporus s.s. probably overwinter in terrestrial or ripar­ian habitats

Aquatic Hydrophilidae and Hydraenidae of Wisconsin (Coleoptera). II. Distribution, Habitat, Life Cycle and Identification of Species of Hydrobiini and Hydrophilini (Hydrophiudae: Hydrophilinae)

Nine genera and 30 species of Hydrobiini and 3 genera and 12 species of Hydrophilini were found in Wisconsin, including a new species of Laccobius. Life cycles of all species of lentic Hydrobiini were similar; adults overwinter in terrestrial habitats, return to aquatic sites in spring to mate, oviposit adjacent to these sites, and eventually die. The riparian larvae complete development, pupate, and emerge sometime during the summer depending on the species and habitat, and teneral adults disperse to suitable aquatic habitats. Adults enter overwintering sites in late summer or early autumn. Lotic species of Cymbiodyta have a similar life cycle, with larvae probably developing along stream banks. Other lotic species, Crenitis digesta, Hydrobius melaenus, and Sperchopsis tessellata, apparently are semivoltine with both larvae and adults overwintering along margins of streams. In Hydrophilini, life cycles of Hydrochara and Hydrophilus are the same as described above for lentic Hydrobiini, except larvae are aquatic, developing in lentic habitats. Life cycles of Tropisternus also differ in having aquatic larvae; they differ further in having adults that overwinter in aquatic habitats, especially streams, deep ponds, and lakes, which they enter in late summer and autumn. Tropisternus ellipticus is lotic, with larvae and adults inhabiting streams, and larvae completing development in mid-summer. Keys to species of adults are included along with information about each species, which includes distribution and abundance in Wisconsin, range in North America, habitat, life cycle, and notes on identification

Aquatic Hydrophilidae and Hydraenidae of Wisconsin (Coleoptera). I. Introduction, Key to Genera of Adults, and Distribution, Habitat, Life Cycle, and Identification of Species of \u3ci\u3eHelophorus\u3c/i\u3e Fabricius, \u3ci\u3eHydrochus\u3c/i\u3e Leach, and \u3ci\u3eBerosus\u3c/i\u3e Leach (Hydrophilidae), and Hydraenidae

The 3,920 Helophorus (Helophorinae) adults collected in Wisconsin included 16 species, two of which were new species. Helophorus orientalis and H. lacustris predominated. Three types of univoltine life cycles occurred: (1) adults overwinter in terrestrial habitats and larvae complete development in riparian habitats from early summer to early autumn, depending on the spe­cies; (2) the same as type 1, except eggs and a few adults overwinter; (3) larvae, pupae, and/or recently emerged adults overwinter and teneral adults occur in aquatic habitats in early spring. Nine species of Hydrochus (Hydrochinae) were found among 6,278 adults, with H. squamifer predominating. All had a similar univoltine life cycle in which adults overwinter in terrestrial habitats and enter aquatic sites in spring; larvae complete development in riparian habitats from late spring to late summer, depending on the species. Eight species and 5,167 adults of Berosus (HydrophIlinae: Berosini) occurred. WIth B. striatus predominating; their univoltine life cycles varied greatly among species. Some species overwinter as diapausing eggs (B. aculeatus, B. peregrinus, B. stylifer), others as adults in terrestrial habitats (B. pantherinus, B. fraternus), one as aquatic larvae (), and another as adults and larvae (B. fraternus). Only 35 Hydraenidae adults were collected; included were Hydraena angulicollis, H. pennsylvanica, and Ochthebius lineatus. A generic key to aquatic Hydropbilidae adults and keys to species of Helophorus, Hydrochus, Berosus, and Hydraenidae in Wisconsin are provided. Following each species key is information about species that includes distribution and abundance in Wisconsin, range in North America, habitat, life cycle, and notes on identification