Kelly V. Tindall

Plant-mediated interactions between the rice water weevil and fall armyworm in rice

Greenhouse studies were conducted to investigate plant‐mediated interactions between an above‐ground and a below‐ground herbivore when sharing a common host plant, rice (Oryza sativa L). Two common pests of rice were used: the rice water weevil (RWW), Lissorhoptrus oryzophilus Kuschel, as the root herbivore, and the fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) as the foliage‐feeding herbivore. Rice water weevil larval performance was assessed by measuring larval density and average weight in response to different levels of defoliation by FAW larvae. The reciprocal experiment was done to evaluate FAW performance (growth rate) in response to RWW feeding. Severe defoliation by FAW decreased RWW densities by 32% and reduced larval weights by 48% compared to larvae on roots of non‐defoliated plants. Effects in the converse experiments were not as strong. FAW growth rates were reduced 9–37% when feeding on rice leaves from plants damaged by RWW compared to larvae feed leaves from the no damage treatment. These reciprocal negative effects show that RWW and FAW are potential competitors when sharing a rice plant. Because RWW and FAW did not interact directly, competition was plant‐mediated.

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

ABSTRACT 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.

Tarnished Plant Bug (Hemiptera: Miridae) Thresholds for Cotton Before Bloom in the Midsouth of the United States

ABSTRACT Insecticide applications to control tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), during cotton, Gossypium hirsutum L., bud formation are common throughout the Midsouth of the United States. Cultivation practices and the pest complex have changed since action thresholds were established for this pest. A trial was conducted at 33 locations over 3 yr throughout the Midsouth to evaluate tarnished plant bug damage to cotton during the prebloom period. There was no consistent yield response to action thresholds, but average tarnished plant bug density and average square loss were both significant factors impacting lint yield. Based on the yield responses and application frequency of the various action thresholds, the best economic scenario occurred when tarnished plant bug density during the prebloom period averaged eight per 100 sweeps and square retention averaged 90%. The action thresholds required to achieve these averages are expected to be higher than these levels because pest pressure is not normally constant during the prebloom period. When insecticides are required, an application interval shorter than one week may be needed to obtain satisfactory control.

Lepidoptera (Crambidae, Noctuidae, and Pyralidae) Injury to Corn Containing Single and Pyramided Bt Traits, and Blended or Block Refuge, in the Southern United States

ABSTRACT Fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae); corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae); southwestern corn borer, Diatraea grandiosella Dyar (Lepidoptera: Crambidae); sugarcane borer, Diatraea saccharalis F. (Lepidoptera: Crambidae); and lesser cornstalk borer, Elasmopalpus lignosellus Zeller (Lepidoptera: Pyralidae), are lepidopteran pests of corn, Zea mays L., in the southern United States. Blended refuge for transgenic plants expressing the insecticidal protein derivative from Bacillus thuringiensis (Bt) has recently been approved as an alternative resistance management strategy in the northern United States. We conducted a two-year study with 39 experiments across 12 states in the southern United States to evaluate plant injury from these five species of Lepidoptera to corn expressing Cry1F and Cry1Ab, as both single and pyramided traits, a pyramid of Cry1Ab×Vip3Aa20, and a pyramid of Cry1F×Cry1Ab plus non-Bt in a blended refuge. Leaf injury and kernel damage from corn earworm and fall armyworm, and stalking tunneling by southwestern corn borer, were similar in Cry1Fx×Cry1Ab plants compared with the Cry1F×Cry1Ab plus non-Bt blended refuge averaged across five-plant clusters. When measured on an individual plant basis, leaf injury, kernel damage, stalk tunneling (southwestern corn borer), and dead or injured plants (lesser cornstalk borer) were greater in the blended non-Bt refuge plants compared to Cry1F×Cry1Ab plants in the non-Bt and pyramided Cry1F×Cry1Ab blended refuge treatment. When non-Bt blended refuge plants were compared to a structured refuge of non-Bt plants, no significant difference was detected in leaf injury, kernel damage, or stalk tunneling (southwestern corn borer). Plant stands in the non-Bt and pyramided Cry1F×Cry1Ab blended refuge treatment had more stalk tunneling from sugarcane borer and plant death from lesser cornstalk borer compared to a pyramided Cry1F×Cry1Ab structured refuge treatment. Hybrid plants containing Cry1F×Cry1Ab within the pyramided Cry1F×Cry1Ab blended refuge treatment had significantly less kernel damage than non-Bt structured refuge treatments. Both single and pyramided Bt traits were effective against southwestern corn borer, sugarcane borer, and lesser cornstalk borer.

First Records of Piezodorus guildinii 1 in Missouri

Redbanded stink bug, Piezodorus guildinii (Westwood), is an important pest of soybean, Glycine max L., in South America (Panizzi and Slansky 1985b, Arroyo and Kawamura 2003) and Louisiana (Paxton et al. 2007). The ability to utilize numerous host plants (Panizzi and Slansky 1985b, Panizzi 1997) allows early season reproduction before redbanded stink bug moves into soybeans at the preferred stage of plant growth. Seed quality and yield are reduced because redbanded stink bug prefer to feed on fruiting structures (Panizzi and Slansky 1985a, Corrêa-Ferreira and de Azevedo 2002). Application of insecticide to protect soybean yield can reduce grower profits (Paxton et al. 2007) The redbanded stink bug has been found in Florida (Panizzi and Slansky 1985b) and Georgia (McPherson et al. 1993). In 2000, redbanded stink bug was observed in south-central Louisiana (Temple et al. 2007). By 2004, redbanded stink bug had increased to outbreak levels across the south-central parishes and reached the northeastern corner of Louisiana. In 2005, redbanded stink bugs were documented in Arkansas and continue to be found in southern Arkansas soybeans (Smith et al. 2009). In 2009, redbanded stink bug was found during surveys of late-planted fields R6-7 (Fehr et al. 1971) soybeans in Dunklin and New Madrid counties, MO (Table 1). These occurrences were the first records of redbanded stink bug in Missouri. Soybean field locations were determined using a Garmin eTrex GPS (Garmin Ltd., Olathe, KS). Sixteen fields in six southeastern Missouri counties were surveyed by sweep net (200 sweeps per field) for late-season stink bugs. Adult stink bugs with the exception of redbanded stink bug were identified using McPherson (1982). J. E. McPherson (personal communication) confirmed the identification of the redbanded stink bug adults. The few stink bug nymphs encountered were not identified or counted.

Bioassays for monitoring insecticide resistance.

Pest resistance to pesticides is an increasing problem because pesticides are an integral part of high-yielding production agriculture. When few products are labeled for an individual pest within a particular crop system, chemical control options are limited. Therefore, the same product(s) are used repeatedly and continual selection pressure is placed on the target pest. There are both financial and environmental costs associated with the development of resistant populations. The cost of pesticide resistance has been estimated at approximately

Effect of Depth of Flooding on the Rice Water Weevil, Lissorhoptrus oryzophilus, and Yield of Rice

1.5 billion annually in the United States. This paper will describe protocols, currently used to monitor arthropod (specifically insects) populations for the development of resistance. The adult vial test is used to measure the toxicity to contact insecticides and a modification of this test is used for plant-systemic insecticides. In these bioassays, insects are exposed to technical grade insecticide and responses (mortality) recorded at a specific post-exposure interval. The mortality data are subjected to Log Dose probit analysis to generate estimates of a lethal concentration that provides mortality to 50% (LC50) of the target populations and a series of confidence limits (CLs) as estimates of data variability. When these data are collected for a range of insecticide-susceptible populations, the LC50 can be used as baseline data for future monitoring purposes. After populations have been exposed to products, the results can be compared to a previously determined LC50 using the same methodology.

Lady Beetle (Coleoptera: Coccinellidae: Coccinellinae) Occurrences in Southeastern Missouri Agricultural Systems: Differences between 1966 and Present

Abstract The rice water weevil, Lissorhoptrus oryzophilus (Kuschel) (Coleoptera: Curculionidae), is a semi-aquatic pest of rice and is the most destructive insect pest of rice in the United States. Adults oviposit after floods are established, and greenhouse studies have shown that plants exposed to deep floods have more eggs oviposited in leaf sheaths than plants exposed to a shallow flood. Experiments were conducted in three mid-southern states in the USA to determine if the depth of flooding would impact numbers of L. oryzophilus on rice plants under field conditions. Rice was flooded at depths of approximately 5 or 10 cm in Arkansas in 2007 and 2008 and Louisiana in 2008, and at depths between 0–20 cm in Missouri in 2008. Plants were sampled three and four weeks after floods were established in all locations, and also two weeks after flood in Missouri. On all sampling dates in four experiments over two years and at three field sites, fewer L. oryzophilus larvae were collected from rice in shallow-flooded plots than from deep-flooded plots. The number of L. oryzophilus was reduced by as much as 27% in shallow-flooded plots. However, the reduction in insect numbers did not translate to a significant increase in rice yield. We discuss how shallow floods could be used as a component of an integrated pest management program for L. oryzophilus.

Halyomorpha halys (Hemiptera: Pentatomidae): a First Kansas Record

ABSTRACT Several species of lady beetles are of conservation concern due to the extirpation of some species from large areas of North America. Historical lady beetle specimens from New Madrid and Pemiscot Counties, Missouri were examined and compared to recent captures. Adalia bipunctata (L.), Anatis mali (Say), Anatis labiculata (Say), and Coccinella novemnotata Herbst were present historically, but have not been collected since 1970. Coccinella septempunctata L., Harmonia axyridis (Pallas), and Neoharmonia venusta (Melsheimer) are relative newcomers to the study area. The non-native species, C. septempunctata and H. axyridis, combined accounted for the majority of lady beetle captures within the study area during 2008 and 2009. The implications of the historical data with regard to these changes are discussed.

Distribution of the long-horned beetle, Dectes texanus, in soybeans of Missouri, Western Tennessee, Mississippi, and Arkansas.

Halyomorpha halys (Stål) is a non-native, pentatomid pest in North America and is commonly known as the Brown Marmorated Stink Bug (ESA, 2011), or BSMB. It was first documented in North America from Allentown, Pennsylvania during fall of 1996 (Hoebeke and Carter, 2003). Eaton (2011) lists detection of H. halys in 33 of the United States: all states east of the Mississippi River and also: Minnesota, Iowa, Nebraska, Arizona, California, Oregon, and Washington. Since 2005, H. halys has also been detected multiple times in California, but it is not known to be established (Daugherty, 2011). Halyomorpha halys was first discovered in Pennsylvania as a nuisance over-wintering in human homes (Hoebeke and Carter, 2003); it is also gaining notoriety because it has potential to be a serious agricultural pest (Nielsen and Hamilton, 2009). On 29 September 2011, at approximately 17:30, one adult individual of H. halys was found on a wall in the gas station, EZ GO #70, at mile marker 209 of the Kansas Turnpike in Douglas County, Kansas in the city of Lawrence by KVT and KF. The specimen was retained and resides in the collection of KVT. Further searching of the area and inquiring with employees did not yield additional specimens. The specimen was identified using characters in Hoebeke and Carter (2003). That this occurrence is the first record of H. halys for Kansas is supported by BM’s communications with the Kansas State University entomology faculty and search of the Kansas State University insect collection. Hoebeke and Carter (2003) postulate that shipping containers from China, Korea, or Japan may have introduced H. hayls into North America. It was first found in Nebraska in a shipping crate (Nebraska State Insect Records Database 2012) which is consistent with this postulate. Our Kansas record, along a major route for interstate commerce, may also have resulted from phoresy associated with human activity. This manuscript provides a reference point of when H. halys was first detected within the state of Kansas. Future searches will likely discover more individuals and possibly even established populations.