REPRODUCTIVE AND DEVELOPMENTAL BIOLOGY OF CHELINIDEA VITTIGER t'HLER (HEMIPTERA: COHEIDAE) by STANLEY CLAY CARROLL, B.S. A THESIS IN ENTOMOLOGY Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Reauirements for the Degree of MASTER OF SCIENCE Approved Aecerted p, . ' . ... !ri ..... -, ;. ~ ••• ~ •, ,r ..... : • 1... , , • .. ,.-~;.~: t' \. _.. ,, ,! I •' ••' I J 1" I ;,,, t!J I i , I ' AC~~OWLEDG1'IENTS Special appreciation is extended to Dr. James K. Wangberg for his encouragement, direction, and guidance as the chai~~an of my committee. Dr. Darryl P. Sanders and Dr. Joe R. Goodin are also extended my appreciation for the suggestio~s and constructive criticism during the development and completion of my graduate studies. Sincere thanks also go out to Dr. David E. Foster, former Texas Tech professor, for his guidance at the initiation of this study. My wife, Cheryl, is also thanked for her patience and assis- tance in preparing my thesis. This study was conducted through the facilities and financial resources provided by Texas Tech University. To this institution I am indebted. ii TABLE OF CONTENTS ACK1~0WLEDG11ENTS ......................................... i i LIST OF TABLES .......................................... i v LIST 0 F FIGURES . v LIST OF APPENDICES ...................................... vi I . INTRODUCTION. 1 Review of Lit era ture. 5 I I . METHODS AND \lATER I ALS .......................... 16 Laboratory Colonization of Chelinidea vittiger .......................... 16 Rearing Techniques for Data Collection ................................... 18 III. RESULTS ru~D INTERPRETATIONS .................... 26 Temperature Effects on Nymphal Development . ................................. 26 Staggered Nymphal Development ................ 32 P reov1pos. 1•t• 1on. 3°...; Reproduction Potential ....................... 36 Adult Longevity .............................. 44 IV. SUMMARY AND CONCLUSIONS ........................ 45 LITERATURE CITED ........................................ 48 .APPEi\TD I CE S . 50 iii LIST OF TABLES 1. Duration (Days) of the various life stages of Chelinidea vittiger as reported by previous researchers ............................. 13 2. Percentage of Chelinidea vittiger nymphs dying in each life stage whe~ reared at six constant temperatures (Based upon the most advanced stage reached by each nymph). Lubbock, Texas, 1978-79: ......................... 27 3. Relative humidity ranges recorded for the six temperature treatmen~s. The ranges are based on the lowest and highest relative humidity readings and also the most common range observed. Lubbock, Texas} 1978-79 ......... 28 4. Developmental time requirements for those 1st instar Chelinide~ vittlger nyTiphs reaching the adult stage when reared at three constan~ temperatures. Lubbock, Texa.s, 1978-79 ................................... 31 5. Preoviposition requirements for Chelinidea vittiger when reared at three constan~ temperat1rres. Lubbock, Texas, 1978-79 ........... 34 iv LIST OF FIGURES 1. Life stages of Chelinidea vittiger (left to right: adult, third instar nymph, eggs) ............. 2 2. Heavy infestation of Opuntia in the Rolling Plains of Texas. 2 3. Chlorotic lesions; the initial symptom caused by the feeding activity of Chelinidea vittiger ...... 10 ~- Vinyl plastic cage and enclosed prickly pear cactus plant utilized in rearing Chelinidea vittiger ............................................ 19 o. Mean number of eggs produced per week by the ovipositing Chelinidea vittiger females caged at three constant temperatures for the initial fourteen weeks of the adult stage. Weekly means based on the number of ovipositing females living at each inspection. Lubbock, Texas, 1978-79 . ..................................... 39 6. Mean number of eggs produced per week by Chelinidea vittiger females (both ovipositing and non-ovipositing) caged at three constant temperatures for the initial fourteen weeks of the adult stage. Weekly means based on the total number of females living at each inspection. Lubbock, Texas, 1978-~9 ............................. 40 7. Cumulative mean number of eggs produced by the ovipositing Chelinidea vittiger females caged at three constant temperatures for the initial fourteen weeks of the adult stage (after Lublinkhof 1976). Lubbock, Texas, 1978-79 .......... 42 8. Cumulative mean number of eggs produced by Chelinidea vittiger females (both ovipositing and non-ovipositing) caged at three constant temperatures for the initial fourteen weeks of the adult stage (after Lublinkhof 1976). Lubbock, Texas, 1978-79 ............................. 43 v LIST OF APPENDICES A. Developmental data for the nymphs of Chelinidea vittiger reared at six constant temperatures. Lubbock, Texas, 1978-79 ............................. 51 B. Chi-Square analysis of the Chelinidea vittiger nymphs reaching the adult stage when reared at six constant temperatures. Lubbock, Texas, 1978-79 ............................................ 57 c. Analysis of variance and Duncan's multiple range test for the time Chelinidea vittiger nymphs require to reach the adult stage when reared at three constant temperatures. Lubbock, Texas, 1978-79 ...................................... 58 D. Nymphal development of Chelinidea vittiger nymphs reared under similar environmental conditions. The nymphs originated from seven pairs of adults producing eggs at 31°C. Lubbock, Texas, 1979 ................................ 59 E. Analysis of variance for the immature develop­ ment of Chelinidea vittiger. Analysis is based upon the egg incubation and nymphal development periods combined for 24 nymphs originating from four pairs of adults. Lubbock, Texas, 1979 ......... 62 F. Analysis of variance for the comparison of the i~~ature development of the males versus females of Chelinidea vittiger. Analysis is based upon the combined egg incubation and nymphal development periods for eight females and thirteen males reared under similar environ- mental conditions. Lubbock, Texas, 1979 ............ 63 G. Analysis of variance and Duncan's multiple range test for the preoviposition time require­ ments of Chelinidea vittiger females producing eggs when reared at three constant temperatures. Lubbock, Texas, 1978-79 ............................. 64 H. Reproductive behavioral responses of ~_e_l_i_n_l_·d__ e_a vittiger females reared at six constant temp- eratures. Lubbock, Texas, 1978-79 .................. 65 vi Appendix J. Chi-Square analysis for egg production of Chelinidea vittiger females reared at six constant temperatures. Lubbock, Texas, 1978-79 ............................................ -71 J. Analysis of variance and Duncan's multiple range test for the reproductive potential of Chelinidea vittiger females producing eggs when reared at three constant temperatures. Analysis is based upon the mean number of eggs produced per week over the lifetime of each female but excluding the preoviposition period. Lubbock, Texas, 1978-79 .................... 72 K. Egg production in the initial 14 weeks of the adult stage for Chelinidea vittiger females reared at six constant temperatures. Lubbock, Texas, 1978-79 ...................................... 7 ~ L. Longevity of the adult stage in Chelinidea vittiger females and males when reared at six constant temperatures. Lubbock, Texas, 1978-79 ............................................. 78 vii CHAPTER I INTRODUCTION Chelinidea vittiger Uhler, one of four species collec­ tively known as the cactus bugs, is documented as one of the most important of the native enemies of prickly pear (Fig­ ure 1). Hunter et al. (1912) concluded in their study of the insects affecting cactus that the cactus bugs are by far the most important native enemy of prickly pear cactus (Opuntia spp.) found in the United States. This decision was based upon the prolific breeding and the wide distribu­ tion of C. vittiger in the United States. This cactus bug attacks most, if not all, species of prickly pear cactus within tts range of distribution (Mann 1969). It is reported to be found in essentially all regions of the prickly pear distribution, extending from the Atlantic coast across to the Pacific coast and into northern ~exico (Dodd 1940, Mann 1969). Prickly pear infests millions of acres of rangeland often unchecked by other less competitive range plant species (Figure 2). Although many control methods have been inves­ tigated for prickly pear cactus, biological control is often the only feasible approach. Prickly pear species often 1 2 .Figure 1. Life stages of Chelinidea vittiger (left to right; adult, third instar nymph, eggs). Figure 2. He.:-avy infestation of _9pu~t . \i~~ ~r~ the Rolli.ng n-- .· · · f ,.., ..: .L~.J.l1!-> o. _ exas. 3 invade relatively inferior land, and the low-value-per-acre of the rangeland prohibits the use of other control methods. Due to the permanent nature of the control, biological control programs utilizing insect species have already proved successful in suppressing prickly pear infestations at a relatively low cost. In recent months there has been a renewed interest i~ a possible biological control program against prickly pear in the southern areas of the United States. Since Opuntia species serve some regions as a valuable forage for livestock in periods of drought and also as a source of human food, the cactus is not considered to be a pest in some areas. If a conflict of interest exists, it might be necessary to uti­ lize indigenous arthropod species instead of inGroducing exotic species. Understanding