ECOLOGICAL STUDIES ON LACE BUGS (HEMIPTERA: TINGIDAE) ON THEIR MAJOR HOST PLANTS IN KHARTOUM STATE BY Abd alla Abdel rahim Satti B.Sc. (Agric.) Hons., University of Gezira M.Sc. (Agric.), University of Khartoum A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy Supervisor Prof. El-Imam El-Khidir Department of Crop Protection Faculty of Agriculture University of Khartoum December – 2003 1 TABLE OF CONTENTS Page ACKNOWLEDGEMENTS …………………………………….. iv ABSTRACT ……………………………………………………. v ARABIC ABSTRACT …………………………………………. Vi 1. INTRODUCTION …………………………………………… 1 2. REVIEW OF LITERATURE ……………………………….. 5 2.1. Lace bugs (= tinged bugs) ……………………………….. 5 2.1.1. Classification ………………………………………… 5 2.1.2. Description …………………………………………… 8 2.1.3. Life history and ecology ……………………………... 9 2.1.4. Distribution and damage ……………………………... 10 2.1.5. Natural enemies ……………………………………… 12 2.1.5.1. Parasites………………………………………….. 12 2.1.5.2. Predators………………………………………….. 12 2.1.6. General control measures ……………………………. 18 2.1.6.1. Cultural methods …………………………………. 18 2.1.6.2. Insecticidal control ………………………………. 19 2.2. Eggplant lace bug (= eggplant tingid bug) ………………. 19 2.2.1. Taxonomy ……………………………………………. 19 2.2.2. Description …………………………………………… 20 2.2.3. Life history and bionomics …………………………... 21 2.2.4. Ecology ………………………………………………. 22 2.2.5. Distribution …………………………………………... 23 2.2.6. Host plants …………………………………………… 23 2.2.7. Damage and economic importance ………………….. 24 2.2.8. Natural enemies …………………………………….. 25 2.2.9. Control ……………………………………………….. 25 2.3 "Adasi" lace bug ………………………………………….. 26 2.3.1. Taxonomy ……………………………………………. 26 2.3.2. Distribution …………………………………………... 26 2.3.3. Host plants …………………………………………… 27 2.4. Sunflower lace bug ………………………………………. 27 2.4.1. Taxonomy ……………………………………………. 27 2.4.2. Description …………………………………………… 27 2.4.3. Life history …………………………………………… 28 2.4.4. Ecology ………………………………………………. 28 2.4.5. Distribution …………………………………………... 29 2.4.6. Host plants …………………………………………… 29 2.4.7. Damage ………………………………………………. 30 2.4.8. Control ……………………………………………….. 30 2 3. MATERIALS AND METHODS ……………………………. 31 3.1. Field experiments ………………………………………… 31 3.1.1. Eggplant ……………………………………………… 31 3.1.2. Pigeon pea …………………………………………… 32 3.1.3. Sunflower …………………………………………….. 32 3.2. Field surveys ……………………………………………... 33 3.2.1. Lace bugs and their hosts plants ……………………... 33 3.2.2. Predators and their hosts plants ……………………… 33 3.3. Laboratory work …………………………………………. 34 3.3.1. Monitoring of lace bug parasites …………………….. 34 3.3.2. Morphological presentation of important lace bug species ………………………………………………... 34 3.3.3. Durations of the pre-adult stages of important lace bug species on some of their major host plants .……... 35 4. RESULTS ……………………………………………………. 39 4.1. Encountered lace bugs and their host plants ……………... 39 4.2. General morphological and behavioural observations …… 65 4.3. Seasonality of lace bugs and their distribution within host plants ………………………………………………... 67 4.4. Damage inflicted by the different lace bug species ……… 92 4.5. Duration of the pre-adult stages of some important species on their major host plants ………………………... 97 4.6. Natural enemies of lace bugs and their seasonal abundance ………………………………………………... 103 5. DISCUSSION ………………………………………………... 137 REFERENCES……………………………………………… 151 3 ACKNOWLEDGEMENTS Firstly, praise and thanks be to Allah, Lord of the world, who gave me strength and ability to conclude my research work. Secondly, I am very grateful and deeply indebted to my supervisor, Prof. El Imam El Khidir, for his thorough knowledge that makes us love and enjoy the science of ecology, not merely of our insects, but of our animals, plants, peoples and planet too. Through continuous investigations and invaluable dialogues he offers, the research time has passed unfelt. Also, it is a pleasure to acknowledge that kind helps I have received from the staff members and technicians of the Department of Crop Protection, Faculty of Agriculture, University of Khartoum (U. of K.), throughout the study period. I appreciate the cooperation provided between the National Centre for Research (NCR), University of Sudan (U. of S.), particularly the Faculty of Agricultural Studies, and the Faculty of Agriculture, U. of K., which facilitated the performance of the field experiments at Shambat. Special thanks are due to Dr. Seifel Din M. Khair and the staff members of the Department of Crop Protection, U. of S., for their fruitful cooperation. Thanks are also due to Dr. Sami A. Hamid, for permitting using his valuable Canon Camera during the field surveys, and to Dr. Abdel Wahab Hassan, for providing sunflower seeds. Finally, I deeply acknowledged the fund executed to this study by the Ministry of Sc. and Tech., and the help rendered to me by the Environment and Natural Resources Research Institute (ENRRI), NCR. I am grateful in particular to Dr. Osman E. Nasr, Head of the Department of Biocontrol and Alternatives to Pesticides, ENRRI, for encouragement, and to my colleaques Seifel Din, Mogbil and Abdel Muniem for their helps in various ways. The real assistant of Mogbil A. El Nuari made the difficulties of surveys and recognition of some new insects in the field, more possible and fruitful. Thanks are lastly extended to Ikhlas Y., for patience in typing this thesis. 4 ABSTRACT Ecological studies on lace bugs (Hemiptera: Tingidae) were carried out during three consecutive years (2000 – 2002) in Khartoum State, where these pests were investigated in their natural habitats. The research work was executed through field experiments, extensive field surveys on cultivated and wild hosts plants, and was supported by some laboratory work. Species present in the area with new ones, together with their host plants were recorded. Some essential features of the detected lace bugs were drawn. The seasonality of important species, their distribution on host plants, and the characteristics of damage inflicted were closely followed under field conditions. The duration of immature stages were also studied in the laboratory. Moreover, natural enemies were evaluated in various habitats. A total of nine lace bug species and nineteen host plants were found, from which six pests and thirteen hosts were new records. Urentius spp. were never found infesting the same host plants together, as believed. These species revealed an increase in their population build up twice a year, both at the end of rainy and winter seasons. On the other hand, Galeatus scrophicus Saunders and most of the newly encountered lace bugs peaked once, only during winter season. Some species with camouflaging habits were discussed. Different feeding patterns exhibited on leaves by the various lace bugs were explained. Various groups of general predators were found. Spiders (various species) were the dominant group associated with lace bugs during all seasons, followed by chrysopids and lastly, coccinellids. Prevalence of these predators on the bug host plants and other plants not attacked by the bugs were thoroughly discussed. Field management to preserve such natural enemies was thought essential. 5 ﺍﻟﺨﻼﺼﺔ ﺃﺠﺭﻴﺕ ﺩﺭﺍﺴﺎﺕ ﺒﻴﺌﻴﺔ ﻋﻠﻰ ﺤﺸﺭﺍﺕ ﺒﻕ ﺍﻟﺘﻨﺠﺩ (Lace bugs) ﺍﻟﺘﻲ ﺘﺘﺒﻊ ﻟﻠﻌﺎﺌﻠﺔ Tingidae ﺘﺤﺕ ﺭﺘﺒﺔ ﻨﺼﻔﻴﺔ ﺍﻷﺠﻨﺤﺔ (Hemiptera) ﻋﻠﻰ ﻋﻭﺍﺌﻠﻬﺎ ﺍﻟﻤﺨﺘﻠﻔﺔ ﺒﻭﻻﻴﺔ ﺍﻟﺨﺭﻁﻭﻡ ﻓﻲ ﺍﻟﻔﺘﺭﺓ ﻤﻥ 2000 ﺇﻟﻰ 2002 ، ﻭﺫﻟﻙ ﻤﻥ ﺨﻼل ﺇﺠﺭﺍﺀ ﺍﻟﻌﺩﻴﺩ ﻤﻥ ﺍﻟﺘﺠﺎﺭﺏ ﺍﻟﺤﻘﻠﻴﺔ ﻭﺍﻟﻤﺴﻭﺤﺎﺕ ﺍﻟﻤﻴﺩﺍﻨﻴﺔ ﻋﻠﻰ ﺍﻟﻌﻭﺍﺌل ﺍﻟﻤﺨﺘﻠﻔﺔ ﺒﺎﻹﻀﺎﻓﺔ ﻟﺒﻌﺽ ﺍﻟﺘﺠﺎﺭﺏ ﺍﻟﻤﻌﻤﻠﻴﺔ. ﻫﺩﻓﺕ ﺍﻟﺩﺭﺍﺴﺔ ﺇﻟﻰ ﺍﻟﺘﻌﺭﻑ ﻋﻠﻰ ﺍﻷﻨﻭﺍﻉ ﺍﻟﻤﻭﺠﻭﺩﺓ ﻭﺒﻌﺽ ﻤﻼﻤﺢ ﺼﻔﺎﺘﻬﺎ ﻭﺴﻠﻭﻜﻴﺎﺘﻬﺎ ﻭﻋﻭﺍﺌﻠﻬﺎ ﺍﻟﻬﺎﻤﺔ. ﻫﺫﺍ ﺒﺎﻹﻀﺎﻓﺔ ﻟﺩﺭﺍﺴﺔ ﺍﻟﺘﻌﺩﺍﺩ ﺍﻟﻤﻭﺴﻤﻲ ﻟﻸﻨﻭﺍﻉ ﺍﻟﻬﺎﻤﺔ ﻭﺘﺤﺩﻴﺩ ﻜﻴﻔﻴﺔ ﺘﻭﺯﻴﻌﻬﺎ ﻋﻠﻰ ﺍﻟﻨﺒﺎﺕ ﻭﻤﻥ ﺜﻡ ﻁﺒﻴﻌﺔ ﺍﻟﻀﺭﺭ ﺍﻟﻨﺎﺠﻡ ﻋﻥ ﺍﻟﺘﻐﺫﻴﺔ. ﺍﺸﺘﻤﻠﺕ ﺍﻟﺩﺭﺍﺴﺔ ﺍﻟﻤﻌﻤﻠﻴﺔ ﻋﻠﻰ ﺘﺤﺩﻴﺩ ﻁﻭل ﻓﺘﺭﺓ ﺍﻷﻁﻭﺍﺭ ﻏﻴﺭ ﺍﻟﻜﺎﻤﻠﺔ ﻭﺫﻟﻙ ﺨﻼل ﻤﻭﺴﻤﻲ ﺍﻟﺨﺭﻴﻑ ﻭﺍﻟﺸﺘﺎﺀ. ﻤﻥ ﻨﺎﺤﻴﺔ ﺃﺨﺭﻯ ﺘﻀﻤﻨﺕ ﺍﻟﺩﺭﺍﺴﺎﺕ ﻭﺍﻟﻤﺴﻭﺤﺎﺕ ﺍﻟﺤﻘﻠﻴﺔ ﺍﻟﺘﻌﺭﻑ ﻋﻠﻰ ﺍﻷﻋﺩﺍﺀ ﺍﻟﺤﻴﻭﻴﺔ ﺍﻟﻤﺘﻭﺍﺠﺩﺓ (ﺨﺎﺼﺔ ﺍﻟﻤﻔﺘﺭﺴﺎﺕ) ﻭﻤﺴﺘﻭﻴﺎﺕ ﺘﻌﺩﺍﺩﻫﺎ ﺍﻟﻤﻭﺴﻤﻲ ﻭﺘﻭﺯﻴﻌﻬﺎ ﻋﻠﻰ ﻤﺨﺘﻠﻑ ﺍﻟﻌﻭﺍﺌل. ﻟﻘﺩ ﺘﻡ ﺍﻟﺘﻌﺭﻑ ﻋﻠﻲ ﻋﺩﺩ ﺘﺴﻌﺔ ﺃﻨﻭﺍﻉ ﺤﺸﺭﻴﺔ ﻤﻥ ﺒﻕ ﺍﻟﺘﻨﺠﺩ ﻭﺘﺴﻌﺔ ﻋﺸﺭ ﻨ ﻭ ﻋ ﺎﹰ ﻤﻥ ﺍﻟﻌﻭﺍﺌل ﺍﻟﻨﺒﺎﺘﻴﺔ ، ﺒﻴﻨﻬﺎ ﺴﺘﺔ ﺃﻨﻭﺍﻉ ﻤﻥ ﺍﻟﺤﺸﺭﺍﺕ ﻭﺜﻼﺜﺔ ﻋﺸﺭ ﻨ ﻭ ﻋ ﺎﹰ ﻤﻥ ﺍﻟﻌﻭﺍﺌل ﺘﺴﺠل ﻷﻭل ﻤﺭﺓ. ﺘﺅﻜﺩ ﺍﻟﻨﺘﺎﺌﺞ ﻋﻠﻲ ﻭﺠﻭﺩ ﻋﻭﺍﺌل ﻤﻨﻔﺼﻠﺔ ﻟﻜل ﻤﻥ ﺒﻕ ﺍﻟﺒﺎﺫﻨﺠﺎﻥ ( Urentius hystricellus) ﻭﺒﻕ ﺍﻟﻌﺩﺴـﻲ (U. euonymus). ﺃﻭﻀـﺢ ﺍﻟﺘﻌـﺩﺍﺩ ﺍﻟﻤﻭﺴﻤﻲ ﺒﺄﻥ ﻤﺠﺎﻤﻴﻊ ﻫﺫﻩ ﺍﻵﻓﺎﺕ (.Urentius spp) ﺘﺯﺩﺍﺩ ﺒﺩﺭﺠﺔ ﻜﺒﻴﺭﺓ ﺨﻼل ﻓﺘﺭﺘﻴﻥ ﻓﻲ ﺍﻟﻌﺎﻡ، ﻋﻨﺩ ﻨﻬﺎﻴﺔ ﻜل ﻤﻥ ﻤﻭﺴﻤﻲ ﺍﻟﺨﺭﻴﻑ ﻭﺍﻟﺸﺘﺎﺀ. ﺩﺭﺠﺔ ﺍﻹﺼﺎﺒﺔ ﺒﺘﻨﺠﺩ ﺯﻫﺭﺓ ﺍﻟﺸﻤﺱ (Galeatus scrophicus) ﻭﻤﻌﻅﻡ ﺍﻷﻨﻭﺍﻉ ﺍﻷﺨﺭﻯ ﺘﺯﺩﺍﺩ ﺒﺼﻭﺭﺓ ﻭﺍﻀﺤﺔ ﺨﻼل ﻤﻭﺴﻡ ﺍﻟﺸﺘﺎﺀ. ﻟﻘﺩ ﺍﺸﺘﻤﻠﺕ ﺍﻟﻨﺘﺎﺌﺞ ﺃﻴﻀﺎ ﻋﻠﻲ ﻤﻨﺎﻗﺸﺔ ﺒﻌﺽ ﺍﻟﻤﻼﺤﻅﺎﺕ ﺍﻟﺴﻠﻭﻜﻴﺔ ﻟﺒﻌﺽ ﺃﻨﻭﺍﻉ ﺍﻟﺘﻨﺠﺩ ﻤﺜل ﺍﻟﻤﻤﺎﺘﻨﺔ (ﺍﻟﺘﺨﻔﻲ) ﺒﻐﺭﺽ ﺍﻟﺤﻤﺎﻴﺔ ﻤﻥ ﺃﻋﺩﺍﺌﻬﺎ ﺍﻟﻁﺒﻴﻌﻴﺔ. ﻭﺃﺒﺎﻨﺕ ﺍﻟﺩﺭﺍﺴﺔ ﻭﺠﻭﺩ ﺍﺨﺘﻼﻓﺎﺕ ﻫﺎﻤﺔ ﻓﻲ ﻜﻴﻔﻴﺔ ﻭﻤﻭﻀﻊ ﺃﺤﺩﺍﺙ ﺍﻟﻀﺭﺭ ﺒﺄﻭﺭﺍﻕ ﺍﻟﻌﺎﺌل ﺘﻡ ﺘﺩﻭﻴﻨﻬﺎ ﻟﻤﻌﻅﻡ ﺍﻷﻨﻭﺍﻉ. ﻜﺫﻟﻙ ﺃﻅﻬﺭﺕ ﺩﺭﺍﺴﺔ ﺍﻷﻋﺩﺍﺀ ﺍﻟﺤﻴﻭﻴﺔ ﻭﺠﻭﺩ ﺃﻋﺩﺍﺩ ﻜﺒﻴﺭﺓ ﻤﻥ ﺍﻟﻤﻔﺘﺭﺴﺎﺕ ﺍﻟﻌﺎﻤﺔ ﺍﻟﺘﻲ ﺘﺘﻐﺫﻯ ﻋﻠﻲ ﺍﻟﺘﻨﺠﺩ ﻭﻏﻴﺭﻫﺎ ﻤﻥ ﺍﻟﺤﺸﺭﺍﺕ. ﻤﻥ ﺃﻫﻡ ﻤﺠﻤﻭﻋﺎﺕ ﻫﺫﻩ ﺍﻟﻤﻔﺘﺭﺴﺎﺕ ﺒﺎﻟﻨﺴﺒﺔ ﻟﺒﻕ ﺍﻟﺘﻨﺠﺩ، ﻤﺠﻤﻭﻋﺔ ﺍﻟﻌﻨﺎﻜﺏ – Spiders (ﺃﻨﻭﺍﻉ ﻤﺨﺘﻠﻔﺔ)، ﺘﻠﻴﻬﺎ ﻤﺠﻤﻭﻋﺔ ﺃﺴﺩ ﺍﻟﻤﻥ (chrysopids)، ﻭﺃ ﺨ ﻴ ﺭ ﺍﹰ ﻤﺠﻤﻭﻋﺔ ﺃﺒﻭ ﺍﻟﻌﻴﺩ (coccinellids)، ﻭﺍﻟﺘﻲ ﺘﻡ ﻓﺤﺼﻬﺎ ﻓ ﺤ ﺼ ﺎﹰ ﻤﺴﺘﻔﻴﻀﺎ ﻤﻥ ﺤﻴﺙ ﺘﻭﺯﻴﻌﻬﺎ ﻋﻠﻲ ﺍﻟﻨﺒﺎﺘﺎﺕ ﺍﻟﻌﺎﺌﻠﺔ ﻟﻠﺘﻨﺠﺩ ﻭﻏﻴﺭﻫﺎ ﻤﻥ ﺍﻟﻨﺒﺎﺘﺎﺕ ﺍﻻﺨﺭﻱ ﺒﺎﻟﺤﻘل ﻟﻤﻌﺭﻓﺔ ﺃﻭﺴﻊ ﻻﺩﺍﺀ ﺩﻭﺭﻫﺎ ﻓﻲ ﺍﻟﺘﻭﺍﺯﻥ ﺍﻟﺒﻴﺌﻲ. 6 1. INTRODUCTION The Sudan is considered as one of the twelve largest countries in the world, with its area account for 967,500 square miles, lies wholly within the tropics, between latitudes 22º and 3º North and longitudes 38º and 22º East. Topographically, the country is more or less a uniform plains, except for few altitudes such as Marra and Nuba Mountains in the west and the Red Sea Hills in the east, which have limited effect on the climate of these areas. Most of this large area is a fertile land of potential