The Effect of Temperature, Relative Humidity And Exposure To Sunlight Upon The Mexican Bean Beetle

Abstract

MILLER: MEXICAN BEAN BEETLE AND CLIMATIC FACTORS 945 quently the influence of each borer of population on the percentage of transportation of food material is correspondingly less as the size of plant increases and as a result, the smaller stalk varieties suffer greater damage. CONCLCSION. In planning this project it was hoped that by ascertaining the ratio existing between borer population and reduction in yield, the damage occurring within any field could be readily computed after determining the borer population. However, the results of the investigations reported here indicate that there is not likely to be established a specific formula, based upon borer population per stalk alone, for measuring damage that will apply to all varieties, soils, planting dates, seeding rates, crop rotations and weather conditions. The writers believe that the same populations established on the varieties presented here would not produce identical results another year because of the above mentioned factors. Nevertheless the amount of damage per average borer of population can be correlated in a general way with the nature of the variety according to the scale given in Table 6.

Life Tables and Larval Dispersal of Mexican Bean Beetle (Coleoptera: Coccinellidae) on Dry Bean in the High Plains

“…Larvae usually pupate beneath leaves and on stems located at the lower part of bean plants, so they are less likely to be exposed to direct sunlight reducing the chance of desiccation and the effect of high temperatures. Miller (1930) studied the inßuence of temperature, relative humidity, and sunlight on Mexican bean beetle fourth-stage larvae and pupae. Single exposures of adults, larvae, and pupae to 37.5ЊC for 3 h did not affect survival of individuals at any stage, independent of the relative humidity imposed (0, 30.72, 56.18, 73.14, and 100%).…”

“…Although the biology and ecology of the Mexican bean beetle and the factors affecting its population dynamics have not been studied in the western high plains, there are many studies of beetle biology from other regions of the United States on soybean. Abiotic factors, such as drought, have long been recognized as important factors affecting Mexican bean beetle population dynamics and pest status (Marcovitch and Stanley 1930, Miller 1930, Howard 1931 and play an important role in geographic distribution (Sweetman 1932). Recent studies have established the sensitivity of Mexican bean beetle eggs and larvae to humidity and temperature (Kitayama et al 1979).…”

A dynamic model of water gain and loss in larval Mexican bean beetle

“…Marcovitch & Stanley (1930) found that large larvae and adults survived c. 25 h at 37.5"C and 80% relative humidity (r.h.) without access to host foliage, whereas small larvae died within 8 h. At both 40 and 100% r.h., these survival times were halved. Miller (1930) investigated survival of adults and larvae on Phaseolus under extreme temperatures (37.5-42.5"C) and varying r.h. (O-lOO%) without food or water for 3h. They measured 100% survival at 37.5"C, 88% at 39.5"C, and less than 10% survival at 41.5"C, regardless of humidity.…”

A dynamic model of larval Mexican bean beetle survival as a function of body water balance

“…Host plant species and phenology, temperature, and relative humidity have all been recognized as important factors influencing survival of Mexican bean beetle, Epilachna i3arivesti.r Mulsant (Eddy & McAlister, 1927;Miller, 1930;Sweetman & Fernald, 1930;Howard, 1921;Deitz et al, 1976;Wilson, 1981;Sprenkel & Rabb, 1981;Wilson et al, 1982). However, there are few papers which discuss the relationship between body water content and survival under variable conditions (note review by Wharton & Richards (1978) for lack of quantitative information on this subject).…”

“…However, there are few papers which discuss the relationship between body water content and survival under variable conditions (note review by Wharton & Richards (1978) for lack of quantitative information on this subject). Miller (1930) investigated survival of Mexican bean beetle following exposure to high temperature for 3 h at different relative humidities. He found survival at 73% r.h. of larval Mexican bean bettle to be 100, 96, 89 and 91% at temperature of 37.5, 38.5, 39.5 and 40.5"C, respectively.…”