Volume 46: Issue 1

Formosan subterranean termites, Coptotermes formosanus Shiraki, were tested under laboratory conditions to determine preferences among different sand moisture levels in a choice test. Foraging behavior, rate of filter paper consumption and distribution patterns of the termites were studied among 3 soldier ratios: low (4% soldier), normal (16% soldier) and high (32% soldier) and 7 sand moisture gradients (4, 8, 12, 16, 20, 24 and 28% wt/wt) in a circular 3-dimensional arena. The results showed that sand moisture had a significant effect on termite distribution and filter paper consumption, whereas soldier proportions had no effect. Treatment means comparisons indicated that there were no significant differences in termite distribution or consumption among moisture levels ranging from 4 - 24%; however, significant differences were obtained when termite distribution or consumption on these moisture levels were compared with that of the saturated sand (28% moisture). Termites also were not present in the center release chamber (which had dry sand and no food) at any observation point. Within the range of 4 - 24%, we found a very uneven distribution pattern where 70 - 80% of the total released termites aggregated in 1 of the 6 moisture chambers. Filter paper consumption generally corresponded with the aggregation sites. Importantly, among the 27 replicates no particular moisture chamber was consistently chosen for aggregation indicating that Formosan subterranean termites probably can adapt to a range of substrate moisture levels in nature provided other conditions are suitable.

Insecticide products based on cedar oil are readily available, but evaluations against pine bark beetles (Coleoptera: Curculionidae: Scolytinae) are lacking. In the southeastern U.S., the southern pine beetle, Dendroctonus frontalis Zimm, is the major bark beetle pest for which tree protectants are applied. However, Ips avulsus (Eichhoff) are more consistently available, are easily trapped and can attain pest status at times, making them an attractive option for the evaluation of certain tree protection products. In this study, we evaluated 2 commercial cedar oil products for their ability to prevent attack by I. avulsus on loblolly pine (Pinus taeda L.) bolts. The field method we deployed was an extension of a previously developed laboratory method in which small-bolts are treated with the product and provided a challenge by adult beetles. The new method used multiple-funnel traps baited with synthetic attractants to direct I. avulsus to test bolts. The method was successful in providing a challenge to treatments with I. avulsus, and resulted in neither product being consistently effective for preventing bolt utilization by this beetle. Although not considered effective in the majority of our trials, full-strength (neat) application of cedar oil product reduced bolt utilization by I. avulsus during winter trials (November and February), perhaps due to lower attack pressure from beetles. Evaluations at other times of the year (March through May), or that began > 0 days post-application, resulted in the products consistently failing to meet either of our efficacy criteria. Compared with competing insecticide products (e.g., those based on bifenthrin), the cedar oil products appear to be less effective, require more frequent reapplication and be more expensive.

The choice of an appropriate sample size is a neglected topic in termite sex ratio research because the literature contains a variety of sample sizes with most < 50 individuals. We compared the effect of sample size (from 25 - 800) on matching the ratio obtained from several Reticulitermes flavipes (Kollar) populations of 1600 individuals. This study showed that a sample size of < 50 is too small to estimate the actual sex ratio of a population. A sample size of at least 100 termites is required to provide ±10% error in a census of Reticulitermes sex ratios. The results should improve confidence in estimates of termite colony sex ratios, and we propose a standard sample size for such studies.

Liriomyza trifolii (Burgess), sometimes referred to as the American serpentine leafminer, readily infests greenhouses, and their larvae feed on numerous crops worldwide including ornamentals and vegetable crops (Parella 1987, Annu. Rev. Entomol. 32: 201 - 224). Damage caused by larval mining significantly reduces photosynthetic capacity of the crops and causes leaf fall during heavy infestations (Johnson et al. 1983, J. Econ. Entomol. 76: 1061 - 1063). Apart from direct damage caused by larval feeding on leaf tissues, females may act as vectors for diseases during oviposition (Matteoni and Broadbent 1988, Can. J. Plant Pathol. 10: 47 - 52).

Control

Relationship Between Frankliniella occidentalis (Thysanoptera: Thripidae) Population Density and Three of Its Natural Enemies in Commercial Lemon Orchards in Mexico¹

Saúl Pardo-Melgarejo,

Filemón Morales-Hernández,

Jaime González-Cabrera,

Mario A. Miranda-Salcedo,

Juan Carlos Álvarez-Hernández,

J. Concepción Rodríguez-Maciel,

Alejandra Mondragón-Flores,

Bismarck Aguilar-Garzón, and

Karen Vianey Díaz Arias

Effects of Sand Moisture Level on Food Consumption and Distribution of Formosan Subterranean Termites (Isoptera: Rhinotermitidae) with Different Soldier Proportions

Effectiveness of Cedar Oil Products for Preventing Host Use by Ips avulsus (Eichhoff) (Coleoptera: Curculionidae) in a Modified Small-Bolt Assay

Sample Size Requirement in the Study of Subterranean Termite (Isoptera: Rhinotermitidae) Sex Ratio

Improved Methods for Survey of Carabid Beetles (Coleoptera: Carabidae) Using Pitfall Trapping and Spatial Autocorrelation Techniques

Thrips Species Composition on Onions in the Vidalia Production Region of Georgia

The Korean Species of the Genus Baeocera (Coleoptera: Staphylinidae: Scaphidiinae)

Improved Visualization of Fat Body Cell Conditions and Abundance in the Southern Green Stink Bug (Hemiptera: Pentatomidae)

New Records of Six Staphylinid Species (Coleoptera: Staphylinidae) from Coastal Habitats in Northeastern Russia

Description of a New Crypticus Species (Coleoptera: Tenebrionidae) from Turkey

Control of Liriomyza trifolii (Diptera: Agromyzidae) in Cut Flowers using Isaria fumosorosea (Hypocreales: Cordycipitaceae) Alone and in Combination with Insecticides

Influence of Trap Color on Collection of the Recently-Introduced Bean Plataspid, Megacopta cribraria (Hemiptera: Plataspidae)

Relationship Between Frankliniella occidentalis (Thysanoptera: Thripidae) Population Density and Three of Its Natural Enemies in Commercial Lemon Orchards in Mexico¹

A Review of the Host Plant Records of Phthorimaea absoluta (=Tuta absoluta) (Lepidoptera: Gelechiidae)¹

Carabidae (Coleoptera: Harpalinae: Harpalini: Harpalina) from an Upper Cretaceous Rock Deposit at Orapa Diamond Mine in Botswana¹

Chemical Mechanism of Exogenous Jasmonic Acid-Induced Resistance in Rose Against Spodoptera exigua (Lepidoptera: Noctuidae)¹

Interference with Fatty Acyl-CoA Reductase Reduces Wax Secretion and Influences the Development of Male Ericerus pela (Hemiptera: Coccoidae) Nymphs¹