Sweep Net Methods Research Articles

Biodiversity of Insect Pests in The Agroecosystems of Maize (Zea Mays L.) In Telangana State, India

The study was conducted at maize/ corn crop fields in Nalgonda, Warangal, and Ranga Reddy, erstwhile districts of Telangana state, India, during the 2021–22 Kharif and Rabi seasons. Main objective of the study is to investigate Biodiversity of insect pests in the agroecosystems of maize (Zea mays L.) in Telangana state, India. Sweep net and hand-picking methods were used to collect insect pests on maize/ corn fields. sixteen insect pest’s species were observed, belonging to Coleoptera, Diptera, Hemiptera, Lepidoptera, and Orthoptera orders in the class Insecta of the Arthropoda phylum of the Kingdom Animalia. The order Lepidoptera represented the highest number of eight species followed by Hemiptera three species, Coleoptera two species, Orthoptera two species and Diptera one species. The family Noctuidae of lepidoptera was the richest with eight species followed by Acrididae of Orthoptera with two species, Chrysomelidae of Coleoptera with one species, Scarabaeidae of Coleoptera with one species, Muscidae of Diptera with one species, Aphididae of Hemiptera with one species, Lophopidae of Hemiptera with one species, and Derbidae of Hemiptera with one species on maize/ corn crop fields. Ecological indices of insect pest’s species i.e., Species diversity (Shannon-Wiener Index), Species richness (Margalefs Index) and Species evenness (Pielou Evenness Index) were calculated.

Diversity of Insects of Two Rice (Oryza sativa L. 1787) Farms in Nnamdi Azikiwe University, Awka, Nigeria

The recognition of insect-related damages to rice plants and the subsequent consequences for biodiversity have shown the relevance of insect communities in rice farms. This study documented the insect fauna of rice (Oryza sativa L. 1787) in two rice farms in Nnamdi Azikiwe University, Awka, Nigeria from September to November, 2022. The insects associated with the two sites were collected using handpicking, sweep net, water trap and pitfall trap methods. Data collected from the study were subjected to non-parametric t- test at 5% significant level. A total of 51,021 insects belonging to twelve insect orders were found associated with the two sites. Out of the aforementioned number, 15,120 (29.63%) were collected from site 1 while 35,901 (70.37%) were collected in site 2. There was significant difference (P <0.05) on insect abundance between site 1 and 2. Crematogaster peringueyi was found to be the most abundant (82.67%) insect in site 1, whereas Camponotus perrisi was found to be the most abundant (27.85%) in site 2. The result further showed that only Hobomok skipper had the least relative abundance (0.01%) in site 1, while Catantops quadratu, Anacatantops notatus, Dysdercus cingulatus, Crematogaster peringueyi, Dasyleurotettix infaustus and Apis mellifera had the least relative abundance (0.01%) in site 2. The diversity indices computed showed that Site 1 had a higher Simpson dominance index (0.6845), Shannon Weiner diversity index (1.07597) and Shannon Weiner evenness than site 2 (0.0019, 0.41248and 0.0393 respectively). The Margalef richness index (6.3879) of site 2 was greater than site 1 (4.9876).There is need for regular monitoring of insects in rice farms for sustainable management of the crop.

ESTIMATION OF DIVERSITY-RELATIVE ABUNDANCE AND TEMPORAL DISTRIBUTION OF LEPIDOPTERAN SPECIES FROM AGRO-ECOSYSTEM OF DISTRICT FAISALABAD, PAKISTAN

Pakistan is an agricultural Country having diverse types of soil and irrigation system. Punjab being the most productive province contributes 69% of total land area for agriculture. Faisalabad is one of the most productive regions of Punjab sharing 3985 hectares for cropland usage. Agriculture sector besides providing food and employment also provides a shelter for insect fauna. Lepidoptera, which includes butterflies, moths and skippers, is the second largest order of insects having more than 180 thousand species. Diversity of lepidopteran fauna is largely influenced by availability and type of floral diversity. These lepidopterans act as pest and pollinators at same time. During present study diversity, relative abundance, richness and temporal distribution of lepidopteran fauna (larvae + adult) was explored from four selected crops namely wheat, sugarcane, fodder and vegetables by using quadrat and sweep net and pitfall methods from May 2019 to April 2020. Specimens were collected and identified by using different identification keys at Department of Agri-Entomology, University of Agriculture, Faisalabad, Pakistan. Results showed that Noctuidae family was abundantly distributed (43.27%). Most abundant species was Pieris brassicae with 10.97% relative abundance. Quadrat method was proved to be good method for collection of lepidoptera with 76.79% relative abundance. Autumn season was found most favorable in regards for species distribution and abundance (43.98%). Significant results (p-value < 0.05) were found from all selected crops and seasons. Species richness (H’) was highest in fodder (2.6396) during autumn (2.73). Inshort, lepidoptera diversity, occurrence, richness and relative abundance depends upon cropland ecosystem and environmental conditions.

Monitoring of Water Quality Using Aquatic Insects as Biological Indicators in Bhosga Reservoir, Karnataka, India

Aquatic insects are the utmost generally employed macroinvertebrates in freshwater monitoring and assessment worldwide. However, aquatic insects have received far less attention for the objectives of health and water quality bioassessment, particularly in Kalaburagi, Karnataka. This study examined the abundance of aquatic insects in the Bhosga reservoir and their relationship to physicochemical factors. Water ecosystem health had been assessed using the BMWP, ASPT, and FBI scoring systems from October 2020 to September 2021. Samples were collected monthly by using the sweep net and dip net methods. There were 5964 aquatic insects recorded and divided into 23 families and 6 orders. Hemiptera (53%) was the most dominated aquatic insect family, followed by Coleoptera (16%), Diptera (15%), Odonata (8%), Ephemeroptera (6%), and Trichoptera (2%). Water quality falls under the class 2 category attributing

Diversity of mosquito species and potential arbovirus transmission in long-tailed macaque (Macaca fascicularis) breeding facilities

Background and Aim:Mosquito-borne viral infections are diseases that reduce human and animal health levels. Their transmission involves wildlife animals as reservoirs and amplifying hosts, including long-tailed macaques (Macaca fascicularis), and potentially transmits to humans and vice versa. This study aimed to determine the species diversity, richness, and biting activity of mosquitoes in a long-tailed macaque breeding area facility and discover the presence of Flavivirus and Alphavirus as the two main arboviruses reported to infect macaques.Materials and Methods:Human landing catch, light trap, and sweep net methods were used for mosquito collection around long-tailed macaques cages at parallel times for 12 h (18:00–06:00) for 12 nights. Mosquito species were identified to the species level based on the morphological identification key for Indonesian mosquitoes. Mosquito diversity was analyzed by several diversity indices. Mosquitoes caught using the human landing catch method were pooled based on mosquito species for viral ribonucleic acid extraction. Reverse transcription-polymerase chain reaction (RT-PCR) detected the non-structural protein 5 of the Flavivirus region and the non-structural protein 4 of the Alphavirus region. This study used the man-hour density and man-biting rate formulas for mosquito density.Results:Ten mosquito species were collected, namely, Aedes albopictus, Anopheles aconitus, Anopheles minimus, Anopheles vagus, Armigeres foliatus, Armigeres subalbatus, Culex gelidus, Culex hutchinsoni, Culex tritaeniorhynchus, and Culex quinquefasciatus. The number of mosquitoes caught using the light trap method had the highest abundance. In contrast, the number of mosquito species caught using the sweep net method had lower diversity than the other two methods. Seven mosquito species were obtained using the human landing catch method. The mosquito species with the highest density was Cx. quinquefasciatus within the observed densest period from 20:00 to 21:00. Negative results were obtained from RT-PCR testing on five species detected using universal Flavivirus and Alphavirus primers.Conclusion:The occurrence of mosquitoes in long-tailed macaque breeding facilities can be a source of transmission of zoonotic vector-borne diseases between animals and humans and vice versa.

CHECKLIST OF SPIDERS (ARACHNIDA ARANEAE) FROM CHAMPANER PAVAGADH ARCHAEOLOGICAL PARK, GUJARAT

Spiders are one of the most diverse organisms in the terrestrial ecosystem and occupy the seventh position in global diversity. They are arthropods belonging to the class Arachnida and the order Araneae. Spiders are chiefly entomophagous, ubiquitous, harmless and biocontrol agents. The present study was conducted to document spider diversity in Champaner- Pavagadh Archaeological Park; a world heritage site in Gujarat, India. The spider fauna of this site has never been studied in its entirety despite contributions by many arachnologists in Gujarat. Spiders were collected by using active searching, pitfall, and sweep net methods. The study was conducted from January 2016 to December 2019. In the present research work, we compiled a checklist of spiders from Champaner-Pavagadh, Archaeological Park of Gujarat, India based on their taxonomic identification. A total of 189 species belonging to 106 genera and 32 families were collected during the study. The most dominant families reported were Salticidae followed by Araneidae, Lycosidae, and Theridiidae; Oxyopidae and Thomisidae. Finding twenty-seven new records of spiders is the highlight of this work

Distribution of insects at Gokilapuram paddy field inTheni district, Tamilnadu

A study was carried out to observe the abundance, diversity, richness and evenness of insect species at Gokilapuram paddy fields in two cropping seasons per year during 2018-2020. The insects were collected at every month adapting sweep net, light trap and hand-picking methods. A total of 30 species under 8 orders including 22 families were recorded. Diversity of insects was high during second cropping season followed by first cropping season, 2019-2020 and was low in both the seasons of 2018-2019. Evenness was high during the second cropping season 2018-2019 but low during first cropping season, 2019-2020. The insect abundance was belonging to the families like Grambidae and Noctuidae but high richness was recorded in 2019-2020 during the two crops and the low richness was recorded in second cropping season in 2018-2019 in these families.

Determination of Zygaenidae (Lepidoptera) species by morphological and molecular methods in the Eastern Mediterranean Region of Turkey

Morphological identification of the majority of Zygaenidae species in the Eastern Mediterranean Region of Turkey was undertaken and a phylogenetic tree of these species was generated. Sampling was performed between May and September in 2017 and 2018 in Adana, Hatay, Kahramanmaraş, Mersin and Osmaniye Provinces. This area is a zoogeographical junction between central Anatolia and the Levant. The species were collected by sweep net and visual control methods. Thirteen Zygaenidae species identified: Theresimima ampellophaga (Bayle-Barelle, 1808), Adscita (Adscita) obscura (Zeller, 1847), Jordanita (Tremewania) notata (Zeller, 1847), Jordanita (Praviela) anatolica (Naufock, 1929), Jordanita (Solaniterna) subsolana (Staudinger, 1862) (Procridinae), Zygaena (Mesembrynus) diaphana Staudinger, 1887, Zygaena (Mesembrynus) graslini Lederer, 1855, Zygaena (Mesembrynus) punctum Ochsenheimer, 1808, Zyganea (Agrumenia) olivieri Boisduval, 1828, Zygaena (Agrumenia) carniolica (Scopoli, 1763), Zygaena (Agrumenia) viciae (Denis & Schiffermüller, 1775), Zygaena (Agrumenia) loti (Denis & Schiffermüller, 1775) and Zygaena (Zygaena) filipendulae (L., 1758). Macherey-Nagel NucleoSpin kit was used for DNA extraction and PCR was performed with LCO1490/HCO2198 primer pair for the mtCOI gene region. This analysis effectively separated these genera and species in the phylogenic tree, and these data supported the morphological identification.

Assessing the Potential Infection of Tagosodes orizicolus (Hemiptera: Delphacidae) by Rice Hoja Blanca Virus in Texas.

Tagosodes orizicolus (Muir) is the most important pest of rice in Latin America. Besides causing direct damage called hopperburn from feeding on and ovipositing in rice leaves, this insect pest also transmits rice hoja blanca virus (RHBV, Family Phenuiviridae, Genus Tenuivirus) in a persistent-propagative manner. This pathosystem can cause up to 100% yield loss in Latin American rice fields. T. orizicolus and RHBV symptoms were detected in Louisiana, Mississippi, and Florida rice fields in the 1950s, 1960s, and 1980s. However, neither has been detected in the United States since. Two outbreaks of T. orizicolus on ratoon rice occurred in the fall of 2015 and 2018 in counties southwest and south of Houston, TX. Insects were collected from ratoon rice fields by sweep net methods. Insects from the 2015 and 2018 outbreaks were tested individually and in pools of 10, respectively, for RHBV infection and the cytochrome oxidase 1 (CO1) gene from Delphacidae. No insects were positive for RHBV, however, all samples yielded amplicons for the CO1 gene. Furthermore, the CO1 gene from five 2015 individuals was sequenced and found to have a 100% identity to the Fer26_Argentina and 99.81% identity to the DEL074 Venezuela isolates of T. orizicolus. Five new sequences from 2015 individuals have now been deposited in GenBank. It is imperative to stay up to date on the potential invasion and establishment of this exotic pest of rice in Texas and other rice-growing regions of the United States through continued monitoring and research.

Suitability of Two Sampling Methods for Determining the Population Trends of Certain Sap-Sucking Species Inhabiting Tomato and Cucumber Plantations

Faunistic composition and seasonal abundance of certain sap-sucking species inhabiting tomato and cucumber plantations were determined by using sweep net and direct count methods, during summer seasons of 2015 and 2016 in Assiut Governorate, Northern Upper Egypt. Twelve species belonging to 8 families and 3 orders in addition to the acarid mite were recorded. Heteropteran species were found to be constituted 69.24% of the gathered species. However, Homopteran species were found to be constituted 15.38%. Thysanoptera and Tetranichidae were presented by 7.69% for each. Concerning to the sampling method, 76.92% of the collected species were captured by the sweep net method, while 23.08% were gathered by the direct count method. The recovered species were classified as predominantly predaceous, predominantly phytophagous, predaceous in part and phytophagous in part species. Seasonal abundance of the recorded species was determined. The distinct predators, Coranus aegyptius (Fabricius, 1775) and Orius spp. showed relatively low abundance percentages. The predatory-phytophagous mirid species [Campylomma unicolor Poppius, 1914; Nesidiocoris tenuis (Reuter, 1895); Creontiades pallidus (Rambur, 1839). and Deraeocoris serenus (Douglas & Scott, 1868)], showed different abundance percentages. Amongst these taxa, N. tenuis revealed the highest abundance percentage on tomato plantations with an average of 63.00 and 75.00% during 2015 and 2016 seasons, respectively. The distinct phytophagous species, Thrips tabaci Lindeman, 1889; Bemisia tabaci (Gennadius, 1889) and Tetranychus urticae Koch, 1836 presented the greatest abundance percentages on cucumber when estimated by the direct count method.So, this work can be reflect the importance of sweep net as a suitable sampling method for determine the faunistic composition of the flight predatory insects inhabiting tomato and cucumber. However, direct count can be consider the most suitable method for determine the population trends of mobile or non-mobile arthropods inhabiting the same crops. Also, use of more than one sampling method could be successful to clarify the relation between useful and harmful arthropod species.

Spider fauna (Araneae) of the Sieraków Landscape Park (Central Poland) – preliminary data

The paper presents preliminary data on araneofauna of the selected habitats in the Sieraków Landscape Park, where spiders have not yet been studied. The fauna was sampled by sweep net and pitfall trap methods in crop fields, forest and in the ecotone zones: forest/crop field and forest/lake. It was found 44 spider species and four genera represented by young specimens, i.e. Metellina sp., Neriene sp., Haplodrassus sp. and Xysticus sp. The largest number of taxa (24) was found in the forest/lake ecotone, and the smallest one (10) in the crop field, 200 m distant from the forest. The recorded spiders belong to the common species, but they were characteristic for their biotopes.

KEPADATAN POPULASI DAN PREFERENSI HABITAT Anopheles ludlowae DI BERBAGAI EKOSISTEM DI SULAWESI TENGAH

Anopheles ludlowae is specifically known as malaria vector found in Sulawesi. The aim of study was to investigate population and breeding place of An. ludlowae in several ecosystems of Central Sulawesi. The study was conducted in Malino, Tanah Mpulu, and Lalombi villages, South Banawa sub district, Donggal district, Central Sulawesi province. There were six observed ecosystems i.e. settlements where were close and distant from a jungle area, settlements where were close and distant from non-jungle area, and settlements where were close and distant from a coastal area. Mosquitoes were caught using a man landing, animal bite trap, sweep net and light trap methods. All traps were set up at 6 p.m. and collected at 6 a.m. Trapped mosquitoes were identified based on key of morphological characteristic identification. Surveillance of mosquitoes larvae was carried out at some potential places of breeding sites i.e. holes around a river, wetland lagoon and other sites. The result demonstrated that An. ludlowae tended to suck blood of livestock and human. The highest population was MHD 4.42 head/person/hour found at settlements where were far from non-jungles. The holes around a river were the breeding place preference of An. ludlowae.

Effects of Diamide Insecticides on Predators in Soybean.

Predatory arthropods can be important for preventing insect pests from reaching damaging levels in soybean. However, the predator community can be compromised when pest control strategies include the application of broad-spectrum insecticides. The use of selective insecticides such as diamides could conserve predators while still providing necessary pest control. We evaluated two selective diamide insecticides, chlorantraniliprole and flubendiamide, and a broad-spectrum insecticide, lambda-cyhalothrin in combination with chlorantraniliprole, for impact on predators in soybean. We applied insecticides to field plots and documented predator abundance prior to and up to 3 wk postapplication using sticky card, beat sheet, and sweep net sampling methods. In sweep net samples, total predator abundance in plots treated with the selective insecticides was not significantly different from untreated control plots. For beat sheet samples, there were no significant differences in the abundance of total predators on any day postapplication between the selective diamide insecticides or the untreated control, but abundance decreased after application of lambda-cyhalothrin + chlorantraniliprole and did not recover. For sticky cards, there were no differences in predator abundance among treatments on any day postapplication. Over all, results showed that there were no significant differences in the abundance of total predators, Anthocoridae, Araneae, or Geocoridae after application of flubendiamide or chlorantraniliprole compared with the untreated control for up to 3 wk after application. All insecticides significantly decreased populations of lepidopteran pests compared with the untreated control, but only lambda-cyhalothrin + chlorantraniliprole reduced predatory arthropod abundance.

Diversity and equitability of insect pests and natural enemies in brinjal field treated with insecticide

Experiment was conducted during winter season to study the diversity and equitability of insect pest species and natural enemies in insecticide treated brinjal fields. Highest number of insect pests were recorded in` Tracer 45 SC, Bactoil (Bt), Nimbicidene 0.03 EC and lowest was in Necstar-50 EC and Proclaim-5 SG treated plots. The highest total abundance of insect pest was recorded in the plots treated with Bactoil and Tracer-45 SC and lowest total abundance was in Helicide (HNPV), Proclaim-5 SG and Booster-10 EC treated plots. The diversity index and equitability of insect pest species were highest in the plots treated with Nimbicidene 0.03 EC and Bactoil in visual search and sweep net methods while Bactoil and Booster 10 EC in pitfall trap method. However, lowest diversity index and equitability were obtained from the plots treated with Booster 10 EC, Proclaim-5 SG, Necstar-50 EC, Tracer-45 SC in visual search and sweep net methods but also in plots treated with Nimbicidene 0.03 EC in pitfall trap method. In case of natural enemies, the highest number of families were recorded in Tracer-45 SC, Nimbicidine 0.03 EC and Bactoil treated plots while lowest was in Helicide, Booster 10 EC, Proclaim-5 SG and Necstar-50 EC treated plots. The highest total abundance of natural enemy was recorded in the plot treated with Bactoil and Tracer-45 SC while lowest abundance was in the plot treated with Necstar-50 EC and Boster-10 EC. The diversity index and equitability of natural enemies were the highest in the plots treated with Proclaim-5 SG, Bactoil, Helicide and Necstar-50 EC in visual search, sweep net method and pitfall trap method while lowest was in Booster 10 EC, Tracer-45 SC treated plots in visual search method, Booster 10 EC and Nimbicidene 0.03 EC treated plots in sweep net method, Necstar-50 EC and Nimbicidene 0.03 EC treated plots in pitfall trap method. Bactoil and Tracer-45 SC were relatively safe for natural enemies and therefore would be fit well into integrated pest management (IPM) against BSFB of brinjal crop.Jahangirnagar University J. Biol. Sci. 4(1): 71-80, 2015 (June)

Arthropods Associated with Corn Planted in the Marginal Uplands of Inopacan, Leyte

A study was conducted to assess and identify the arthropods associated with corn planted in the marginal uplands of Inopacan, Leyte, using pan trap and sweep net methods, done biweekly during the two cropping periods. Two major groups of arthropods were recorded which included the Arachnids and the insect group, consisting of nine (11) orders of insects represented by 59 insects species and 20 spiders. These arthropods belonged to phytophagous groups (chewing and sucking arthropods); natural enemies (predators and parasitoids) and the innocuous groups or considered “others” (scavengers and saprophagous) The most abundant insect pest species in corn were the Chrysomelidae and Scarabaeidae beetles, while leafhoppers (Homoptera) were moderately abundant in the crop. The predators were mostly ants (Hymenoptera), the spiders (Arachnids), and coccinellid beetles. The parasitoids included the braconid, ichneumonid, and chalcid wasps. The most abundant non-pest and innocuous species are the Dipterans which are potential hosts or prey of the biotic agents in the corn ecosystem. The abundance of pest species in corn is not yet alarming, which indicates that the pests are not attracted to the crops which were marginal in growth. The natural enemies were also occurring in moderate numbers adequate to suppress abundance of pest species. However, from the results, the corn planted in the marginal upland with chicken dung was observed to have the higher number of insect associations than the other treatments.

Effect of Jasmonic Application on Economically Insect Pests and Yeald in Spring Wheat

Field trials were conducted in spring wheat to observe effects of jasmonic acid (JA) on aphids, thrips and wheat blossom midge (WBM). Two spring wheat varieties (Triso and Kadrilj) were sprayed twice, with two concentrations of JA plus control. Wheat pests and associated natural enemies (Coccinellidae, Empididae and Aphelinidae) were surveyed by direct count and sweep net methods. Thrips larvae and adults and WBM larvae were estimated by dissecting wheat ears. Wheat midge larvae were monitored using white traps in treated and untreated plots. At the end of season, wheat yield was assessed in treated and control plots. There was a significant difference in the number of insect pests and their natural enemies between treatments in both varieties. Plants in control plots had higher numbers of aphids, thrips and midges than in treated plots. There were more aphids, thrips and midges on the variety ‘Triso’ than on ‘Kadrilj’. JA application enhanced wheat yield in treated plots compared to control plots. The results indicated that JA mediated induction of plant defense in wheat plants can improve resistance against insect herbivores. JA could be used to develop environmentally sound crop management with reduced insecticide applications.

Research Note: Lymphatic filariasis (LF) <i>Aedes albopictus</i>: A new entrant

Lymphatic filariasis , an ancient disease is a major global problem infecting more than 120 million men, women and children. Vectors for the causative agent Wuchereria bancrofti were investigated in Abia State, Nigeria. Of all the mosquito vectors encountered using sweep net, test tube and Pyrethrum Knockdown Count (PKC) methods, only Aedes albopictus has not been known to be implicated in the transmission of W. bancrofti -caused lymphatic filariasis. This is no good news considering the health implications and bearing in mind that Aedes albopictus is a competent vector for at least 22 arboviruses. The finding of W. bancrofti in A. albopictus (0.21%) in this study has thrown more light to it being a potential vector and possibly an actual vector of W. bancrofti . Keywords: lymphatic filariasis, mosquito vectors, Wuchereria bancrofti, Aedes albopictus , new entrant.

The Impact of Pareuchaetes pseudoinsulata (Lepidoptera: Arctiidae), on the Growth Rate of Chromolaena odorata (L.) in Southern Ghana

The abundance and effectiveness of Pareuchaetes pseudoinsulata Rego Barros (Lepidoptera:Arctiidae) in controlling the Siam weed, Chromolaena odorata (L.) King and Robinson in southern Ghana wasassessed in C. odorata infested fields through monthly sampling and monitoring surveys carried out between October 2007 and March 2008. Insect data was collected using line transects of 100 metres long and 100 metres apart and the removal, sweep net and direct count methods were used and data on the impact of feeding damage on the weed was collected by measuring several plant characteristics. The populations of P. pseudoinsulata were generally low in allsites investigated, throughout the study period. However, higher numbers of the bio-agent were recorded at site #1 (Akotokyire, Central Region) compared to the other sites and this was significantly (P

Sampling Stink Bugs (Hemiptera: Pentatomidae) for Population Estimation and Pest Management in Southeastern Cotton Production

Stink bugs (Hemiptera: Pentatomidae) were sampled in commercial cotton, Gossypium hirsutum L., fields in 2007 and 2008 in South Carolina and Georgia. The main species collected with the beat cloth and sweep net methods were green stink bug, Acrosternum hilare (Say) (63 and 57%, respectively); brown stink bug, Euschistus servus (Say) (23 and 18%, respectively); and southern green stink bug, Nezara viridula (L.) (14 and 22%, respectively). Average stink bug densities were 0.145 +/- 0.010 (mean +/- SEM) for adults and 0.250 +/- 0.027 for nymphs per 3.7 m of row by using the beat cloth method. Average stink bug densities were 0.291 +/- 0.016 for all adults and 0.137 +/- 0.018 for all nymphs per 50 sweeps. A density of two southern green stink bugs per 3.7 m of row by using the beat cloth method required 43 samples (reliability or precision, Dx = 0.3) for population estimation, whereas 88 samples were necessary for a density of two southern green stink bugs per 50 sweeps. At low densities, the sweep net was a more cost-reliable sampling method for all species and life stages. For adult stink bugs, the beat cloth method became more reliable at densities of 1.0, 3.2, and 5.8 stink bugs per 3.7 m of cotton row for southern green stink bug, brown stink bug, and green stink bug, respectively. Sequential sampling consistently reduced sample size for all insects compared with a fixed sampling plan.

Tarnished Plant Bug (Hemiptera: Miridae) Thresholds and Sampling Comparisons for Flowering Cotton in the Midsouthern United States

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), has become the primary target of foliar insecticides in cotton, Gossypium hirsutum L., throughout the Midsouth over the past several years. This prompted a reevaluation of existing action thresholds for flowering cotton under current production practices and economics. A trial was conducted at 19 locations throughout the Midsouth during 2006 and 2007. Threshold treatments ranged from a weekly automatic insecticide application to a very high threshold of 10 tarnished plant bugs per 1.5 row-m on a black drop cloth. Individually, all locations reached the lowest threshold, and eight locations had a significant yield loss from tarnished plant bugs. Across all locations, lint yield decreased 0.85 to 1.72% for each threshold increase of one tarnished plant bug per 1.5 row-m. Yield loss was most closely correlated to pest density during the latter half of the flowering period. The relationship between plant bug density or damage and yield was similar for drop cloth, sweep net, and dirty square sampling methods, but the correlations among these sampling methods were not high. Incorporating actual insecticide application data from the trial and average production and economic factors for Midsouth cotton, the economic threshold, if monitoring once per week, should be between 1.6 and 2.6 tarnished plant bugs per 1.5 row-m during the flowering period. More frequent monitoring or situations where insecticide applications are more efficacious may alter this threshold.