COMPARISON OF SAMPLING METHODS FOR INSECT PESTS OF CANTALOUPE

Sampling of cantaloupe fields was conducted during three growing seasons to determine insect pests present on melons in the lower Rio Grande Valley [Texas USA]. Comparisons were made between two sampling methods (visual observations and a combined suction/visual technique) and three sample area sizes (1, 2, and 3 m2) during two of the seasons to determine sampling precision and efficiency. Five species and one species complex [Diabrotica undecimpunctata howardi, Acalymma vittatum, Aphis, gossypii, Empoasca abrupta and Liromyza spp.] of insects considered as pests were monitored. Means, relative variation (RV), and relative net precision (RNP) for sampling techniques and sample area sizes were compared. Suction sampling followed by immediate visual examination of the plant material vacuumed yielded lowest RV values and highest RNP values. The largest-size area sampled resulted in lowest RV and RNP values for both techniques. The required number of samples associated with differing degrees of precision for both methods and all sample areas was very large.