Rhagoletis fruit flies are strongly attracted to relatively large yellow surfaces that act as leaf mimics. Our objective was to determine whether apple maggot, Rhagoletis pomonella (Walsh), and cherry fruit fly, R. cingulata (Loew), (Diptera: Tephritidae) are more attracted to small yellow deposits than other colors, and whether contrast with the background modifies the response to deposit color. The experimental setup consisted of Petri dish arenas with sucrose deposits on the inside surface of the cover or the bottom. Female flies were introduced individually into the arena, and flies were either observed for 5 min or until they touched the sucrose with their labellum. Initially, translucent-colored deposits were produced by drawing a colored dot outside the cover of the same size as a sucrose deposit placed inside. In later trials, sucrose deposits contained pigment and wax emulsion and were opaque. More apple maggot flies found translucent yellow deposits than black, red or clear. When opaque deposits were used, there were no differences in the numbers of apple maggot flies that found deposits of different colors, but more cherry fruit flies found yellow than white, pink or blue deposits. Contrast cues were produced by depositing colored sucrose on the bottom of the Petri dish and placing the dish on a white or black background. More apple maggot and cherry fruit flies found yellow deposits than black or white, but the number of flies of both species that found a deposit strongly contrasting with the background was not significantly different from those finding the yellow deposit. We conclude that apple maggot and cherry fruit fly find small yellow deposits, or colors strongly contrasting with the background, more often than other colors, and that the response to color cue varies in different species.

The variation in instar number and the pattern of sequential instar development time of Tenebrio molitor L. (Coleoptera: Tenebrionidae) was studied under 4 different diet regimes. Addition of dietary supplements consisting of dry potato or a mix of dry potato and dry egg whites significantly reduced the number of larval instars and total development time. The pattern of sequential stadia length showed regularity and low variability in instars 5 - 9. Stadia length continuously increased between instar 10 and the last instar before pupation (P₋₁). Instar number significantly impacted total development time and was also significantly correlated with stadia length. The length of the 1^st, 2^nd, 3^rd, and 4^th stadia was not significantly affected by diet indicating that they may represent a stable part of the life cycle of T. molitor. The length of the last stadium (P₋₁) was regular within food treatments regardless of sequential instar number, but P₋₁ was also significantly affected by nutrition in a similar way as all the sequential stadia. The pattern of instar variation is discussed in regard to the insertion of new instars based on variation of stadia length.

Twenty-two species collected with Malaise traps are recorded for the first time from Spain. These are: Agromyza anthracina Meigen, 1830; A. bromi Spencer, 1966; A. hiemalis Becker, 1908; A. megalopsis Hering, 1933; Aulagromyza buhri(de Meijere, 1938); Au. luteoscutellata (de Meijere, 1924); Au. similis (Brischke, 1880); Au. trivitatta (Loew, 1873); Cerodontha (Poemyza) lapplandica (Rydén, 1956); Liriomyza amoena (Meigen, 1830); L. erucifolii de Meijere, 1944; L. graminivora Hering, 1949; L. samogitica Pakalniškis, 1996; Melanagromyza eupatorii Spencer, 1957; M. nibletti Spencer, 1957; M. spinulosa Spencer, 1974; Ophiomyia labiatarum Hering, 1937; O. penicillata Hendel, 1920; Phytobia cerasiferae (Kangas, 1955); P. lunulata (Hendel, 1920); Phytomyza bupleuri Hering, 1963; and Ph. tanaceti Hendel, 1923. These new reports increase the total number of known agromyzid species in Spain to 287. In addition, M. spinulosa is a new report for Europe. Information on host plants, phenology, development, and distribution are included.

Malaise traps were operated for 3 yrs (2004 - 2007) at 2 locations in Spain. Agromyzid adults were collected from plant material that was periodically removed from one of those locations. From these sampling efforts, Pseudonapomyza atratula Zlobin, 2002 (Diptera: Agromyzidae), a species previously reported only from Tunisia, is reported for the first time in Europe (Spain). Specimens were collected from the host plants, Avena barbata Pott ex Link and A. fatua L., which are first records as hosts of this leaf-miner. Males were captured from late-September or the beginning of October continuously through the end of May with 8 to 10 generations annually. Population peaks appeared when average temperatures were in a range of approx. 10 - 20°C. Pseudonapomyza atratula is closely related to P. atra (Meigen); morphological criteria (male genitalia) are provided for taxonomic separation of the two species.

Three sampling methods—sweep-net, hand-vacuum modified from a leaf vacuum/blower, and a wheeled, blower-vacuum designed to blow insects from the foliage into the vacuum port of a leaf vacuum—were compared as methods for sampling insects in sweetpotatoes, Ipomoea batatas L. Results of the 4-yr study at 2 locations in Mississippi showed that the number of insects collected by the blower-vacuum method was lower than the number collected by the other 2 methods. Although results differed with different insect species, the numbers of insects collected in hand-vacuum samples were usually greater than or equal to those collected in sweep-net samples during the first few weeks after planting, but less than those in sweep-net samples late in the season. Based upon these results, sweep-nets are the preferred method for season-long sampling of insects in sweetpotatoes.

Adult and larval coccinellids are important predators of the cotton aphid, Aphis gossypii Glover, in cotton, Gossypium hirsutum L. Adult and larval Coccinellinae and Scymninae were sampled by beat-pan method and identified to species in a 3-year field study (1999 - 2001) conducted in northeast Arkansas. The coccinellids observed in descending order of abundance were Hippodamia convergens Guerin, Scymninae (Scymnus spp. and Diomus spp.), Coleomegilla maculata (Degeer), Harmonia axyridis (Pallas), and Coccinella septempunctata L. Population dynamics and community structure by species for C. maculata, H. axyridis and C. septempunctata were unpredictable within and among years. Based on population densities, timing of colonization, and consistent delayed density-dependent relationship with aphid populations, H. convergens and Scymninae genera (Scymnus spp. and Diomus spp.) were the most important predators of cotton aphids in northeast Arkansas.

Increased occurrence of tick-borne diseases requires the surveillance of tick species associated with humans and the animals they contact. Tick species were collected from canines and deer throughout Arkansas by veterinarians during December 2006 to October 2007, while personnel with the Arkansas Game and Fish Commission collected ticks from hunter-killed deer throughout the 2007 hunting season (Oct-Dec). Five tick species were collected: Ixodes scapularis Say (51%), Amblyomma americanum (L.) (22%), Rhipicephalus sanguineus (Latreille) (12%), A. maculatum (Koch) (7%), Dermacentor variabilis (Say) (6%), and unidentified Amblyomma species (2%). Tick collections from canines were A. americanum (45%), whereas 89% of ticks collected from deer were I. scapularis. These 2 tick species also were found simultaneously infesting the same canine and deer hosts. Our data identify 5 tick species and update the current distribution of each species that may be involved in the Arkansas tick-borne disease cycle.

This study assessed the effect of silicon-based fertilizer treatments on development of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood), while feeding on poinsettia, Euphorbia pulcherrima (Willd. ex Klotzsch). A potassium silicate fertilizer was applied at treatment rates of 0, 50, 100, 400, and 800 ppm silicon as a growing medium drench. The mean development time, proportion (%) of pupae and proportion of T. vaporariorum adult emergence were determined for each assessment period. Total silicon concentration in the aboveground tissues (leaves and stems) of poinsettia plants were measured at 4 time intervals throughout the study, using a plant alkaline fusion technique (PAFT) silicon determination procedure. Total moisture content (g), height (cm), and number of fully-expanded mature leaves of the poinsettia plants also were measured. Our results showed significant differences in silicon concentration with poinsettia plants receiving the 100, 400, and 800 ppm silicon treatments having the highest silicon concentrations (1240, 1193, and 1121 mg kg⁻¹ silicon, respectively) in the aboveground tissues. However, there were no significant differences in development time or emergence rates of T. vaporariorum adults when feeding on poinsettia plants treated with potassium silicate in the nutrient solutions. There also were no significant differences in moisture content (g), height (cm), and number of fully-expanded mature leaves of poinsettia plants associated with the silicon-based fertilizer treatments. Incorporating potassium silicate into nutrient solutions did not confer resistance to T. vaporariorum populations developing on poinsettia leaves, and applications of the silicon-based fertilizer failed to enhance the plant growth parameters measured, height (cm), number of fully-expanded mature leaves, and moisture content (g).

The actual feeding injury of Creontiades signatus Distant (Heteroptera: Miridae) was compared with a simulated technique during 2005, 2006 and 2008 by injecting varying dilutions of pectinase into cotton bolls at different boll sizes (ages) and into 2 or 4 locules to determine if such a technique could be used to reduce the time and labor involved with conducting economic injury level studies in the field. The most accurate simulation occurred in 2008 by injecting 1 μL of 10% pectinase into all 4 locules of a cotton boll. This improved the relationships of injury score to seed cotton, seed, and lint weights. The youngest boll age class of ≥ 2 cm diam. (2 d of age) was not significantly more damaged than the medium age ≥ 2.5 cm (8 d of age) bolls, and both sustained significantly more injury than the large boll classification of ≥ 3 cm (12 d of age). However, small bolls were at least 3 times more likely to abscise than medium-sized bolls, and large bolls did not abscise regardless of treatment. Some damage was observed for large bolls from the injected and actual feeding compared with the controls, but the lint and seed weights were not significantly different for any of the treatments including the controls. Our study characterizes the feeding injury caused by C. signatus and describes a simulated technique that may be used to further economic injury studies.

Abiotic factors, such as temperature, are important in the activity and performance of insecticidal compounds, as they influence biochemical reactions that may either enhance or limit the insecticide effectiveness. The influence of these temperature-mediated factors on the toxicity of insecticides in red and green color morphs of the tobacco-adapted form of the green peach aphid, Myzus persicae (Sulzer), was evaluated using leaf-dip bioassays in laboratory incubators. Postexposure temperatures of 15, 20, and 25°C were evaluated for 4 classes of insecticides: organophosphate (acephate), carbamate (methomyl), pyrethroid (lambda-cyhalothrin), and neonicotinoid (imidacloprid). Except for lambda-cyhalothrin, all the insecticides had positive temperature coefficients that indicated increased toxicity to M. persicae at both 5 (15 - 20 and 20 - 25°C) and 10°C (15 - 25°C) temperature ranges. Postexposure temperature had similar effects on insecticide toxicity to both color morphs. A temperature increase of 5°C, from 15 - 20°C and 20 - 25°C, caused 1.3- to 3-fold increases in toxicity for methomyl, acephate, and imidacloprid in both color morphs. A change of 10°C (15 - 25°C) increased the toxicity of the three chemicals from 2.9- to 6.0-fold. In contrast, the toxicity of lambda-cyhalothrin decreased as the temperature increased, showing a negative temperature coefficient. Because laboratory bioassays are typically used for monitoring insecticide resistance, this study confirms that using standardized temperatures is necessary for diagnosing problems and making recommendations for resistance management programs in aphids.