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Plant derived volatiles are cues used widely that guide the behavior of plant associated insects, influencing both the ability of insects to locate host plants, as well as tritrophic interactions with predators or parasitoids. Therefore, an understanding of how volatiles impact a specific ecological system may aid the development of plants that are less attractive to pests or more amenable to biocontrol. Because each plant-insect interaction is different, it is important to develop bioassays to compare plants with different volatile profiles and assess their comparative attractiveness to specific insects. To this end, we developed a laboratory-based pair-wise choice assay to determine the oviposition preference of fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), a global crop pest, to maize, Zea mays L. (Poaceae) plants with different volatile profiles. An alterna- tive greenhouse-based assay also was developed to assess the effect of different Z. mays plants on the oviposition behavior of Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae), a parasitoid wasp that can be used as a biocontrol agent for S. frugiperda. These bioassays are easily adaptable for use on a range of plant-insect interactions. [ABSTRACT FROM AUTHOR]

Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae) is among the world's worst invasive species, and there is an increasing need for effective control methods for this species. Existing chemical treatments and baits used in managing other invasive ant species may not be as effective for managing W. auropunctata. Development of effective ant control treatments and baits depends on laboratory experiments to test the potential efficacy of a large number of products and control methods prior to implementation of large-scale field studies. However, anecdotal evidence suggests that laboratory-raised W. auropunctata may respond differently than their wild counterparts to bait types, and if this is the case, laboratory trials may not accurately predict results under field conditions. Here we report on experimental research investigating whether ant colonies raised in laboratories, and those in the field, show different patterns of recruitment to non-toxic baits. Laboratory and wild colony recruitment to non-toxic Hawaii Ant Lab gel bait, pureed tuna, and 50% gelled sucrose solution was measured via multi-choice and no-choice field recruitment studies. Secondly, we discuss experiments testing whether the bait preference of laboratory-raised W. auropuncata varies with their base diet. We tested 4 base diets: (1) lipid rich, (2) protein rich, (3) carbohydrate rich, and (4) a "complete" diet with lipid, protein, and carbohydrates offered as a buffet. Overall, we found that laboratory colonies differed from wild W. auropunctata in their foraging behaviors in no-choice and multi choice experiments, particularly in their levels of recruitment to the Hawaii Ant Lab gel bait. This contrast indicates that experimental trials may give misleading indications of potential outcomes of field trials. Further research is needed on optimal laboratory diets for laboratory-reared ant colonies. However, our results suggest that behavioral differences may be mitigated if colonies are maintained on a nutritionally limited diet while conducting laboratory experiments. [ABSTRACT FROM AUTHOR]

The use of non-conventional insecticides and entomopathogenic fungi to control adult mosquitoes is increasing; however, the current methods are designed to evaluate the insecticidal action of the active ingredient. We describe the bioassay method to evaluate the effect of non-conventional insecticides and entomopathogenic fungi to control mosquitoes using the Potter tower. Twenty d after application, entomopathogenic fungi produced a proportion of mortality of 0.49 to 0.82, while non-conventional insecticides produced 100% mortality from 15 min after application. Our results showed that this bioassay could provide basic information on the effect of different non-conventional insecticides and entomopathogenic fungi on adult mosquitoes. [ABSTRACT FROM AUTHOR]

The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) is an economically significant pest of sorghum and maize. Laboratory bioassays are often conducted for convenience and for fall armyworm confinement but as the number of entries and replications increase, the replenishing of fresh tissue daily and the cleaning of insect diet cups or petri dishes becomes laborious. The current study was conducted to determine if agar plates, used to retain leaf moisture, supplemented with benzimidazole, a fungicide that delays leaf senescence and retards fungicide growth, can be used to assess fall armyworm feeding on fresh maize and sorghum leaf tissue with minimal labor. We conducted 2 trials consisting of 3 cultivars of maize with known resistance or susceptibility to fall armyworm feeding, and 4 cultivars of sorghum that are parents of existing mapping populations. The top 2 (whorl) leaves were removed from 36-37- day old plants, 7.6 cm long pieces of leaf were excised, and each piece was placed on a benzimidazole agar plate. One larva per plate was placed on the leaf tissue; the plate was sealed with Parafilm and placed in an incubator for 7 days. Average larval weights for Trial 1 were significantly different than Trial 2 after 7 days, and thus each trial was analyzed separately. For both trials, the larvae that were fed susceptible maize line 'AB24E' had weights that were significantly greater than larvae fed resistant maize lines 'Mp708' and 'FAW1430'. No significant differences in weight were observed for fall armyworm larvae fed on the 4 sorghum lines except for those larvae fed 'Collier' in Trial 2, which had weights significantly greater than larvae fed the other 3 sorghum cultivars (Entry 22, 'Honey Drip', 'AN109'). Thus, the benzimidazole agar plate method is an easy and effective method for assessing fall armyworm feeding on maize and sorghum, and thus can be used to identify maize and sorghum germplasm lines with resistance to fall armyworm. [ABSTRACT FROM AUTHOR]

Laboratory bioassays and caged field trials were conducted to compare the acute toxicities of molluscicide formulations on the neonate, juvenile, and adult development stages of giant African snail (GAS) Lissachatina fulica (Bowdich 1822) and 3 non-target snail species in Barbados. Nine commercially available molluscicides, diatomaceous earth, and a kaolin clay product (Surround WP) were evaluated. High levels of mortality to neonate GAS were seen in all the laboratory molluscicide bioassays except for Surround and diatomaceous earth. The highest mortality rates to neonate GAS were observed from Durham granules and Slugfest treatments tested during field trials. Deadline, Durham granules, Metarex, and Orcal pellets caused the highest rates of mortality to juvenile GAS in our field trials. For adult GAS several molluscicides including Blitzem, Deadline, Durham Granules, Mesurol 75W, Metarex, Orcal pellet, and Slugfest caused greater than 95 % mortality in laboratory bioassays. Field trials showed that Durham granules and Slugfest yielded the highest mortality rates. Sluggo pellet, touted as an environmentally safe molluscicide, did not cause high rates of mortality to juvenile and adult GAS in our field trials, but did cause higher rates of mortality to neonate GAS than the control. The majority of the molluscicides tested in our trials were equally or more lethal to 3 non-target snail species than GAS. Our results identify several effective commercially available molluscicides that can be used to control incipient populations of GAS. However, our results show that the potential impact on non-target snail species during control or eradication programs may be considerable, causing substantial mortality regardless of what brand, active ingredient, or formulation is used. [ABSTRACT FROM AUTHOR]