Studies on the Feculae of Selected Michigan Acrididae (Orthoptera)

Feculae have been used for some years in the study of insect food-habits and biology. Among the past authors who have used them are Frost (1928), Hodson and Brooks (1956), and Morris (1942), who discussed the use of feculae and frass in the identification of insect species in general; Boldyrev (1928), who figured the feculae of the bradyporine katydid Bradyporus multituberculatus; Brown (1937), who described in detail fecular microstructure in the spine-breasted grasshopper Melanoplus bivittatus; Weiss and Boyd (1 950. 1 952), who figured the feculae of representatives of selected insect orders; Gangwere (1 962). who described the various factors responsible for shaping and coloring feculae, and with Morales (Gangwere and Morales, 1964) erected the first formal classification of orthopteroid feculae, and later (Gangwere, 1969) discussed the use of feculae of museum specimens as a shortcut method for determining food-habit; Scott (1964), who constructed a pictorial key to the droppings of cockroaches; Simeone (1964), who described the frass of posting beetles; Bhatia and Chandra (1967), who discussed the effect of food plants on the color, structure, and size of feculae in the locust Schistocerca gregaria; and Sardesai (1 969) who reported on size variation in feculae of larval Lepidoptera. With the partial exception of Gangwere and Morales (1964) and Bhatia and Chandra (!967), investigators have paid scant attention to variations in fecular structure within given species. The present study fills, in part, this gap in our knowledge. It describes those differences in fecular size and structure in selected Michigan acridids that relate to sex of defecator and type of food. It also attempts a statistical measurement of such differences

Field diet of the grasshopper Abracris dilecta Walker (Orthoptera, Acrididae)

Abracris dilecta Walker, 1870 (Orthoptera, Acrididae, Ommatolampinae) ate leafs of at least 14 plant species, in the families Asteraceae, Lamiaceae, Malvales (Sterculiaceae, Tiliaceae or Malvaceae), Poaceae, Fabaceae, Verbenaceae, Aristolochiaceae, Rubiaceae and Melastomataccae. Elephantopus mollis H.B.K. (Asteraceae) and Hyptis suaveolens Poit. (Lamiaceae) comprised 50% of the diet. The diet breadth of A. dilecta was compared to that of other 11 grasshopper species of the same sub-family, with rarefaction curves. The number of plant species eaten by A. dilecta was greater than that of nine other grasshopper species of the same sub-family (Rhachicreagra spp.) but was lower then two others (Microptylopteryx hebardi Rehn, 1905 and Rhachicreagra astytophallus Jago & Rowell, 1981). This results are discussed in view of the broad geographical range and possession of developed wings by A. dilecta, which contrasts with most Ommatolampinae grasshoppers