Contents of stomachs were analyzed. Scats and contents of lower digestive tracts, although obtained in large quantity, were unsuitable for analysis because of the fragmentary nature of the foods they contained. Relative amounts of various kinds of foods in stomachs were estimated; volume was determined by displacement of water or fine shot.
Twenty-three stomachs of adults were selected at random (except for the fact that empty stomachs were discarded) from more than a hundred specimens collected in Douglas County, Kansas, in the period from June, 1954, to June, 1957; the sample included stomachs obtained in nearly all the months of the season of activity. Kinds of foods in stomachs did not differ significantly in regard to the sex of the turtles or to time of year. The stomach of each of two juveniles (included in Table 6) contained a greater variety of animal food than did the stomach of any adult, but no kind of animal was eaten by the juveniles exclusively.
Each of the 23 stomachs contained animal matter and, in addition, all but two contained at least some plant material from dung, which constituted up to 20 per cent of total stomach contents.
Insects were present in each of the 23 stomachs and constituted the bulk of the animal matter; beetles, caterpillars, and grasshoppers (ranked in descending order) were the kinds occurring most frequently and constituting the largest average percentages of total stomach-contents. Most of the beetles were scarabaeids and carabids; the bulk of the caterpillars were noctuids and arctiids. Grasshoppers, with one exception, were of a single species, Melanoplus differentialis. It is noteworthy that two of the kinds of insects frequently eaten (differential grasshoppers and noctuid caterpillars) are of economic importance in that they damage crops.
Table 6.—Kinds of Animals Found in the Stomachs of 25 Terrapene o. ornata of Both Sexes (23 adults, 2 juveniles) from Douglas County, Kansas. Frequency of Occurrence (number of stomachs in which found) is Given for Each Item Listed.
| Frequency of Occurrence | |||
| Adults | Larvae | Total | |
| Gastropoda | |||
| Helisoma sp | 1 | . . . . | 1 |
| Succinia sp | 1 | . . . . | 1 |
| Polygyra sp | 1 | . . . . | 1 |
| Retinella sp | 1 | . . . . | 1 |
| Crustacea | |||
| Procambaris gracilis | 1 | . . . . | 1 |
| Armadillidium vulgare | 4 | . . . . | 4 |
| Orthoptera (Locustidae) | |||
| Locustinae (Melanoplus differentialis) | 13 | . . . . | 13 |
| Oedipodinae | 1 | . . . . | 1 |
| Lepidoptera (unspecified) | . . . . | 1 | 1 |
| Arctiidae | . . . . | 9 | 9 |
| Noctuidae | . . . . | 10 | 10 |
| Pyralidae | . . . . | 1 | 1 |
| Sphingidae | . . . . | 1 | 1 |
| Diptera (Sarcophagidae) | . . . . | 1 | 1 |
| Coleoptera (unspecified) | 3 | . . . . | 3 |
| Cantharidae | . . . . | 1 | 1 |
| Carabidae (unspecified) | 6 | . . . . | 6 |
| Carabidae (Eumolops colossus) | 1 | . . . . | 1 |
| Cerambycidae (Prionus fissicornis) | 1 | . . . . | 1 |
| Chrysomelidae (Diabotrica 12-punctata) | 1 | . . . . | 1 |
| Curculionidae (Calendra parvulus) | 3 | . . . . | 3 |
| Lampyridae (Photinus pyralis) | 2 | . . . . | 2 |
| Lampyridae (Photuris sp.) | 1 | 1 | |
| Phengodidae | . . . . | 1 | 1 |
| Scarabaeidae | 11 | . . . . | 11 |
| Hymenoptera (Formicidae) | 2 | . . . . | 2 |
| Phalangida | 1 | . . . . | 1 |
| Araneida (Epeira) | 1 | . . . . | 1 |
| Diplopoda | 1 | . . . . | 1 |
| Vertebrata (carrion) | . . . . | . . . . | 4 |
Table 7.—Occurrence of Insects, by Frequency and Volume, in Stomachs of 23 Terrapene ornata from Douglas County, Kansas. Relative Volume is Based on Total Amount of Food Material Present, Excluding Stones and Vegetable Material Contained in Dung.
| Insects (all) | Orthoptera | Lepidoptera (larvae) | Coleoptera | |
| Average volumetric percentage | 88.6 | 28.7 | 26.9 | 32.5 |
| Range (volumetric percentage) | trace to 100 | 0 to 100 | 0 to 100 | 0 to 100 |
| Frequency of occurrence (percentage of total stomachs in which found) | 100 | 52 | 65 | 74 |