Cotton Insect Populations: Development and Impact of Predators and Other Mortality Factors
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2 8 2 8 2 5 :; 11111 . ::; 11111 1.0 I"II~~ 1.0 . 11111 . I~ ~1P·2 I~ ~F2 2.2 J:': I~ 136 J.:. I~ L:.t:.i '_ I!. L!. L!. '"' e~ i~ ...L:a.:.u " '"' " 1.1 1.1 ........ r.;:."., -- 111111.25 111111.4 111111.6 111111.25 111111.4 111111.6 MICROCOPY RESOLUTION TEST CHART MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS~1963·A NATIONAL ~VREAIJ Of SlAN()AROS~I96,~A conON INSECT POPULATIONS DEVELOPMENT AND IMPACT OF PREDATORS AND OTHER ~ c:::C MORTALITY FACTORS ex:: rr - 0') c.: ":n 0: '::l 0. cr. 1 Wo. - u: ) c.';J ) ~~= ( -c::; l:::;;;:':' UNITED STATES TECHNICAL PREPARED BY ,U,.j) DEPARTMENT OF BULLETIN SCIENCE AND ~ AGRICULTURE NUMBER1592 EDUCATION ADMINISTRATION ABSTRACT Pye, Robert E. 1979. Cotton insect populations: Development and impact of predators and other mortality factors. U.S. Department of Agriculture, Technical Bulletin No. 1592, 65 pp., illus. Heat input converted to physiological time units may be used to deter mine the development of individual pests and predators and to establish the age stratification of the populations. Plant growth, as well as the predatory activities of predatOI:s and their interrelations with target insects, is related to temperature. Thu6; the host plant development and the interrelations of the crop plants with insect populations may be evaluated. In southern Arizo na cotton, relatively high temperatures place stringent restrictions, includ ing reduced fecundity and fertility, egg desiccation, high pupal losses, and impeded behavioral responses, upon the insect popUlations. Late in the sea son, the cotton plant canopy modifies the microenvironment and insect popUlations expand. Therefore, the summer temperature regim~s occurring in southern A'mona may be considered the overriding mortality factor as well as the driving force in the behavioral and developmental subsystems of .cotton insect population dynamics. KEYWORDS: Hemipterous predators, Hippodamia conuergens, Collops uittatus, Peromyscus, insect population model, prey index. ACKNOWLEDGMENTS The author gratefully acknowledges the assis computer programing used in this study are tance of Raymond Patana who furnished the gratefully acknowledged. copious amounts of prey required for the testing The technical assistance of Richard Carranza from the cultures of the Tucson laboratory. The and William McAda in the biological studies, many suggestions relative to technique and en and Eugene Neemann in the field temperature couragement of D. E. Bryan and C. G. Jackson studies is also gratefully acknowledged. are deeply appreciated. The author also expresses his sincere apprecia The efforts of Kevin Weise, Department of Sys tion to Edward Roth and to E. L. Cockrum, tems Engineering, University of Arizona, Tuc Department of Ecology and Evolutionary Biolo son, in fitting the curves and in developing the gy, University of Arizona, for identifying the mice and furnishing the student field data. Issued July 1979 CONTENTS Page Page Introduction, . .. 1 Numbers of pupae. .. 28 Methods and materials....................... 1 Pupal losses ............................ 29 Elources of predators ..................... 1 Pupal losses to climatic factors .......... 29 Prey accepted ........................... 1 Pupal losses to cultural factors ........... 29 Prey preferred......................... " 1 Pupal losses to biotic factors. .. 30 Calculation of point values (PV) in the prey Adult emergence. .. 30 index profile (PIP) . 2 Adult numbers ......................... 30 Searching capability and interception.. '" 2 Adult losses............................ 31 Protective sites .......................... 3 Model continuation ..................... 31 Protective sites on the cotton plant ........ 3 Other factors ............................... 31 Egg hatch and development of predators ... 5 Insecticide impact ...................... 31 Developmental model adjustments ........ 5 Migration .............................. 32 Mouse feeding tests...................... 5 Discussion ................................. 32 Results and discussion ....................... 6 Conclusions. .. 32 Sinea confusa Caudell .................... 6 Literature cited ............................ 33 Zelus renardii Kolenati. .................. 9 AppendixA ........................... 37 Nabis alternatus Parshley ............... 10 Gollops vittatus and Hippodamia Table I.-Food acceptance by hemipterous conuergens. .. .. 11 predators in close confines ............ 37 Peromyscus spp.......... , . .. 14 Table 2.-Prey consumption (Prey Index The model ................................ 16 Profile- PIP) by various stages of Introduction ......................... 16 hemipterous predators ............... 38 The insects. .. .. .......... 17 Table 3.-Prey preferences of predators The developmental submodel ............... 18 in paired food tests .................. 40 Modification of air temperature by cotton Table 4.-Percentage of prey captured in plants................................ 18 24 h by various stages of hemipterous Reciprocal units of development........ 18 predators tested in arenas held under Nutrition adjustment of RUD .......... 18 several light and temperature regimes .. 47 Age stratification ...................... 19 Table 5.-Mean numbers of predators The natality-mortality submodel . • . .. 21 responding each hour through holes of Initial conditions ...................... 21 various sizes to coddled beet armyworm Population assessments ................ 21 or pink bollworm egg prey. .. 50 Diapause.............................. 21 Table 6.-Spaces withiu the bracts of Oviposition site availability ............ 21 squares and bolls of Deltapine-16 Oviposition and egg loss ............... 22 Upland cotton. .. 51 Egg hatch............................. 22 Egg losses ............................ 23 Table 7.-Prey acceptance by Gollops Egg losses due to bioclimate............ 23 uittatus and Hippodamia conuergens Egg losses to parasitism ............. " 24 adults in close confines .............. 51 Numbers of larvae. .. 25 Table 8.-Longevity and prey consumption Larval losses to bioclimate ............. 25 of adult Gallops uittatus and Hippadamia Larval losses to biotic factors ........... 26 conuergens . ........................ , 52 For sale by the :-:IIPcrintcndellt of Do(·umenl$. e.:;, (;ovcrnmcnt P"lllting Oni"e Washington. D.e. 20·10'2 Stock :s'ullIber OOI-()()0-()3U77-6 CONTENTS-Continued Page Page Table 9.-Fercentage of immobile and Table 17.-Most common sites occupied mobile (in parentheses) prey captured by cotton insects .................... 58 in 24 h by Collops uittatus and Table IS.-Reciprocal units of development Hippodamia conuergens adults ......... 52 (RUD) for larval-pupal development for Table 10.-Duration of stages of 3 insects fed . 59 hemipterous predators reared at 5 Table 19.-Pertinent literature references temperatures and fed live cabbage looper available for population assessments and and beet armyworm larvae ............ 53 diapause of cotton pests and their Table n.-Regression data for the predators in southern Arizona .......... 59 transformation of temperatures to Table 20.-Daily fecundity estimates with reciprocal units of development (RUD) ... 54 RUD as the independent variable . .. 59 Table 12.-Duration of stages of 3 Table 21.-Parameters for the estimation of hemipterous predators held at 25 °0 and the proportions of eggs hatched. .. 60 fed different prey .................... 54 Table 22.-Fecundity and fertility reduction Table 13.-Daily consumption by by high temperatures. .. 60 Peromyscus maniculatus and P. merriami Table 23.-Prey point values (PV) consu.med with single and paired food choices ...... 56 daily by 3 hemipterous predators . .. 61 Table l4.-Emergence of moths from pupae Table 24.-Searching efficiency factors of exposed to mouse predation for 24 h ..... 56 individual predators paired with prey. .. 62 Table 15.-Parameters for the determination Table 25.-Potential survival of pupating of the percentage of individuals in a given insects after cultivation of cotton .......62 instar (equations 3, 4a, b) .............. 57 Appendix B . .. 63 Table 16.-Regression coefficients for Reciprocal unit of development estimation of the modification of air accumulation program. .. 63 temperature by the cotton plant using the linear regression equationy=a+bx ..... 58 COTION INSECT POPULATIONS DEVELOPMENT AND IMPACT OF PREDATORS AND OTHER MORTALITY FACTORS By R. E. Fye' INTRODUCTION The interpretation of results from field experi may be adequate to control the pest without ap ments with biological control agents for pest plying additional control measures. The following species requires that the impact of naturally oc lahoratory studies of Sineaconfusa Caudell, curring mortality factors be assessed so their ac Zelus renardii Kolenati, Nabis alternatus Parsh tion may be separated from that of the introduced ley, Gollops vittatus (Say), and Hippodamia con biological control organism (22).2 Likewise, in vergens Guerin-Meneville, predators common in decisions on controls to be applied to pest species, Arizona cottonfields, were made to develop basic it is necessary to evaluate the potential action of information on the predatory activities of these naturally occurring predators and parasites that species and relate it to field populations. METHODS AND MATERIALS Sources of Predators Prey Accepted The predators were collected from cotton, alfal Various stages of potential prey found in cotton fa, and grain sorghum in the vicinity of Tucson,