Saltatorial Orthoptera as Common Visitors to Tropical Flowers

Abstract

In wet tropical regions of Peru and the Panama Canal Zone, saltatorial Orthoptera were found to visit of certain species of Commelinaceae, Compositae, Gramineae, and Euphorbiaceae. Tettigoniids, especially Coinocephalus, were the commonest visitors, though representatives of Tridactylidae, Gryllidae, and Acrididae were also seen on the flowers. Most were nymphs. In the Commelinaceae, the principal family studied, most of the visitors fed only on the anthers, and some were observed to walk from flower to flower. This behavior suggests that they may effect some pollination. However, their destruction of the anthers, which reduces a flower's potential for more efficient bee pollination, would probably make the orthopterans' net effect on the plant deleterious. A GREAT VARIETY of insects visit flowers, but there is rare mention of saltatorial Orthoptera among them. Ramsay (1960) mentions a specimen of Caedidia simplex (Tettigoniidae) found on chrysanthemum flowers in New Zealand. Wickler (1968) notes that the juveniles of a cicindellid mimic, Condylodera tricondyloides (Tettigoniidae), are found in the of a tree in Borneo. Tettigoniidae were mentioned as flower visitors to Tripogandra cumanensis' (Kunth) R. E. Woodson (Commelinaceae) in Peru by Schuster and Schuster (1971). Further observations in Peru and the Panama Canal Zone have confirmed and extended the knowledge of saltatorial Orthoptera interractions with tropical flowers. Occasional observations were made of various flowers, particularly Commelinaceae, during the period from June 1970 to late February 1972 in the region of Tingo Maria, Peru, and during April 22-23, 1972 on Barro Colorado Island in the Canal Zone. Tingo Maria, at 670 meters on the eastern slopes of the Andes, is in a region of Subtropical Wet Forest (Tosi 1960). Barro Colorado Island is in a region of Tropical Moist Forest (Holdridge and Budowski 1959). Both in Peru and on Barro Colorado Island, the usual sites of observation were open weedy areas, such as clearings and roadsides. Such sites were similar floristically and included abundant Tripogandra cumanensis, some Commelina (Commelinaceae), and similar species of Compositae, Acanthaceae, Euphorbiaceae, and Gramineae in bloom. In Peru, one additional site studied was slightly different. This site, an ecotone area between forest and roadside ditch, contained abundant Zebrina pendula Schnizl. (Commelinaceae) in the shadier parts and T. cumanensis in the sunnier. Also present were two species of Urticaceae and a couple of flowering bushes of Hamelia patens (Rubiaceae). The Orthoptera found on are shown in table 1. By far the most common was a species of Conocephalus (Tettigoniidae), of which only nymphs (various instars) were observed on flowers.2 In Peru, it was found on T. cumarnensis during February, May, June, August, September, October, and November, and is probably present on the throughout the year. Clumps of T. cumrnensis produce large quantities of fresh every day in the year. Conocephalus sp. was observed feeding on the anthers, perhaps also consuming stamen hairs, but not eating other parts of the flower. The insects visited a given flower for approximately five to fifteen minutes, and were, at times, observed to pass directly to another flower. Many of the visited would be left without anthers. This situation occurred only while the were open, i.e., from about 9:00 to about 13: 00 (Schuster and Schuster 1971). In the Commelinaceae, which are open on one day do not reopen the following day. This has the result that, at the beginning of any day's open period, all the are unexploited, and the insects do not waste time and energy visiting exploited the previous day. On only one occasion was Conocephalus sp. seen to eat a petal as well as the anthers. This was on a flower of Commelina diffusa Burm. f. in January 1972. Conocephalus sp. was also encountered on the small pale-purple heads of a roadside composite during May 1971. For example, on May 4, 1971 at 10:45 a.m., Conocephalus sp. was found on flower heads of all six plants of this composite growing at a particular site. They were observed to walk from 1 Now T. serrulata (Vahl) Handlos (D. R. Hunt pers comm.). 2 In both Trinidad and Tobago in August 1967 first and second instar nymphs of Conocephalus sp. and Neoconocephalus sp. were observed chewing the anthers of grasses. Crop analyses revealed that anthers and pollen had been ingested. The later instars and adults fed upon the seeds as these became available. M. G. Emsley, Ed. 138 BIOTROPICA 6(2): 138-140 This content downloaded from 157.55.39.78 on Mon, 20 Jun 2016 07:21:09 UTC All use subject to http://about.jstor.org/terms TABLE 1. Species of Orthoptera observed on in Peru (P) and the Canal Zone (C). unidentified ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~; sp. (Paerperne Pu Pn d) 4'S Anaxq7hv? s p. ( Trigonidiinae ) P ~ ~ ~ s ~ ~ Speiescoflinsec 0 ~ ~ ~ ~~~~~a